JP4817976B2 - Drive control device, drive control method, and program - Google Patents

Description

  The present invention relates to a drive control device, a drive control method, and a program, and in particular, a drive control device for correcting camera shake of an imaging device, a drive control method applied to the drive control device, and a computer that uses the drive control method. Relates to a program to be executed.

  Conventionally, as a device for controlling the position of a driven body, for example, there is a drive control device disclosed in Patent Document 1. In this drive control device, a magnetic detection element such as a Hall element detects the position where the driven body exists and outputs it as a position signal. On the other hand, a position command signal indicating a position where the driven body should be present is input. The drive control device feedback-controls the position of the driven body so that the difference between the position signal and the position command signal converges to zero. The drive control device disclosed in Patent Document 1 is applied to an imaging device, and the driven body is a shift lens for image blur correction.

  FIG. 6 is a block diagram showing a basic control circuit configuration of the drive control device disclosed in Patent Document 1. In FIG.

  In this control circuit, a target signal (position command signal) is input to the subtraction circuit 603 from the outside. On the other hand, the magnetic detection element 601 configured by a Hall element or the like detects the lens position of the shift lens unit 606, and the detection circuit 602 outputs a position signal to the subtraction circuit 603. The subtraction circuit 603 outputs a difference (deviation) between the target signal (position command signal) and the position signal to the amplification circuit 604. The difference (deviation) is amplified by the amplifier circuit 604 and converted into a voltage by the driver circuit 605. This voltage is applied to the shift lens unit 606, and the lens position of the shift lens unit 606 is driven in a direction in which the difference (deviation) becomes zero.

  The shift lens unit 606 includes a drive magnet that is displaced integrally with the shift lens, and a fixed coil for displacing the drive magnet. Then, the fixed coil is energized and excited, and the driving magnet is displaced using an electromagnetic force generated by a change in magnetic flux density distribution due to the excitation. Thereby, the shift lens position of the shift lens unit 606 is displaced.

The magnetic detection element 601 detects the lens position of the shift lens unit 606 by detecting the magnetic flux of the driving magnet that is displaced integrally with the shift lens.
Japanese Patent Laid-Open No. 10-62676

  However, in the above-described conventional drive control device, the magnetic detection element 601 detects not only the magnetic flux of the driving magnet but also the magnetic flux due to the excitation of the fixed coil. Therefore, there is a possibility that the detection circuit 602 may output a false position signal when detecting the magnetic flux by the fixed coil, in addition to outputting a true position signal when detecting the magnetic flux of the driving magnet.

  When a false position signal is output from the detection circuit 602, the applied voltage to the fixed coil increases in a frequency band where the control followability of the driven body (shift lens of the shift lens unit 606) deteriorates. For this reason, the mixing ratio of the false position signal rapidly increases with respect to the true position signal. As a result, there is a problem that the gain margin and the phase margin are lowered, the stability of the feedback control is lowered, and vibration noise is generated.

  The present invention has been made in view of such problems, and has attempted to reduce the influence of a false position signal due to coil excitation, improve the stability of feedback control, and reduce vibration noise. It is an object to provide a drive control device, a drive control method, and a program.

To achieve the above object, according to the first aspect of the present invention, a magnetic body that can be displaced integrally with a driven body, and an energization exciter that is excited by energization and displaces the magnetic body by electromagnetic force. And position detection means for detecting a magnetic flux of the magnetic body and outputting a position signal indicating a position where the driven body exists, and a target for generating a target position signal indicating a target position where the driven body should exist A position command signal for controlling the position of the driven body based on a difference between a position generation unit, a position signal output by the position detection unit, and a target position signal generated by the target position generation unit Drive control means for generating and outputting to the energization exciter, and the position command signal generated by the drive control means is negatively fed back to the position signal output by the position detection means to Due to the magnetic flux exciting body generates possess a feedback means for canceling the position signal false output from said position detecting means, said feedback means is a phase lag relative to the output position signal by said position detecting means Phase compensation means for compensating for phase lag caused by digital processing performed in the target position generation means, the drive control means, and the feedback means in the position command signal generated by the drive control means, and the position detection And a feedback amount adjusting means for adjusting the level of the position command signal generated by the drive control means with respect to the level of the position signal output by the means .

According to a fifth aspect of the present invention, the drive control includes a magnetic body that is displaceable integrally with the driven body, and an energization excitation body that is excited by energization and displaces the magnetic body by electromagnetic force. A drive control method executed by the apparatus, comprising: a position detection step of detecting a magnetic flux of the magnetic body and outputting a position signal indicating a position where the driven body exists; and a target where the driven body should exist Based on a difference between a target position generation step for generating a target position signal representing a position, a position signal output in the position detection step, and a target position signal generated in the target position generation step, the driven body A drive control step for generating a position command signal for controlling the position of the current and outputting the position command signal to the energized exciter; and the position command signal generated in the drive control step Out negative feedback is allowed to output position signals in step, the power excitation body due to the magnetic flux generated possess a feedback step of canceling a location signal false output from said position detecting means, the feedback step A phase lag with respect to the position signal output by the position detection step, the digital being performed in the target position generation step, the drive control step, and the feedback step in the position command signal generated by the drive control step A phase compensation step for compensating for a phase lag associated with the processing, and a feedback amount adjustment step for adjusting the level of the position command signal generated by the drive control step with respect to the level of the position signal output by the position detection step. A drive control method is provided.

Furthermore, Help program to execute the above-described drive control method in a computer is provided.

  According to the present invention, in the drive control device comprising: a magnetic body that can be displaced integrally with the driven body; and an energization exciting body that is excited by energization and displaces the magnetic body by electromagnetic force. A position signal representing the position where the driven body exists is output and a target position signal representing a target position where the driven body should exist is generated. Then, based on the difference between the output position signal and the generated target position signal, a position command signal for controlling the position of the driven body is generated and output to the energized exciter. On the other hand, the generated position command signal is negatively fed back to the output position signal to cancel the false position signal output from the position detecting means due to the magnetic flux generated by the energized exciter.

  As a result, the false position signal output from the position detecting means due to the magnetic flux generated by the energized exciter can be canceled, and the influence of the false position signal can be reduced. Feedback control in the drive control means Stability can be improved and vibration noise can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a digital camera including a drive control device according to an embodiment of the present invention.

  In FIG. 1, reference numeral 101 denotes a zoom unit, which includes a zoom lens that performs zooming. Reference numeral 102 denotes a zoom drive control unit that controls the drive of the zoom unit 101. Reference numeral 103 denotes a shift lens unit whose position can be changed with respect to the optical axis. Reference numeral 104 denotes a shift lens drive control unit, which drives and controls the shift lens unit 103. Reference numeral 105 denotes an aperture / shutter unit. Reference numeral 106 denotes an aperture / shutter drive control unit, which controls the drive of the aperture / shutter unit 105. A focus unit 107 includes a lens that performs focus adjustment. A focus drive control unit 108 controls the drive of the focus unit 107. Reference numeral 109 denotes an imaging unit that converts an optical image that has passed through each lens group into an electrical signal. Reference numeral 110 denotes an imaging signal processing unit that converts an electrical signal output from the imaging unit 109 into a video signal. A video signal processing unit 111 processes the video signal output from the imaging signal processing unit 110 according to the application. Reference numeral 112 denotes a display unit, which displays an image as necessary based on a signal output from the video signal processing unit 111. Reference numeral 113 denotes a power supply unit that supplies power to the entire system according to the application. An external input / output unit 114 inputs / outputs communication signals and video signals to / from the outside. Reference numeral 115 denotes an operation unit for operating the system. Reference numeral 116 denotes a storage unit that stores various data such as video information. Reference numeral 117 denotes a control unit that controls the entire system. The control unit 117 includes, for example, a central processing unit (CPU), a ROM (Read Only Memory) that stores a control program executed by the CPU, a RAM (Random Access Memory) that the CPU uses for calculation, an input / output device, and the like. . When the CPU executes the control program, at least a part of the function of the shift lens drive control unit 104 is realized.

  Next, the operation of the digital camera having such a configuration will be described.

  The operation unit 115 has a shutter release button configured such that the first switch and the second switch are sequentially turned on according to the amount of pressing. The first switch is turned on when the shutter release button is depressed approximately halfway, and the second switch is turned on when the shutter release button is depressed to the end. When the first switch of the operation unit 115 is turned on, the focus drive control unit 108 drives the focus unit 107 to perform focus adjustment, and the aperture / shutter drive control unit 106 drives the aperture / shutter 105 to set an appropriate value. Set to exposure. Further, when the second switch is turned on, the image data obtained from the light image exposed to the imaging unit 109 is stored in the storage unit 116.

  At this time, if there is an instruction to turn on the image stabilization from the operation unit 115, the control unit 117 instructs the shift lens drive control unit 104 to perform the image stabilization operation, and the shift lens drive control unit 104 that receives the instruction instructs the image stabilization off. Anti-vibration operation is performed until

  Further, in this digital camera, one of the still image shooting mode and the moving image shooting mode can be selected from the operation unit 115, and the operating condition of each actuator can be changed in each mode.

  When an instruction for zooming magnification is given to the operation unit 115, the zoom drive control unit 102 that has received the instruction via the control unit 117 drives the zoom unit 101 to place the zoom lens at the designated zoom position. Moving. At the same time, based on the image information sent from the imaging unit 109 and processed by each signal processing unit (110, 111), the focus drive control unit 108 drives the focus unit 107 to perform focus adjustment.

  FIG. 2 is a diagram illustrating a drive mechanism of the shift lens unit 103.

  In FIG. 2, reference numeral 502 denotes a drive magnet, which is made of a magnetic material magnetized with a plurality of poles. Although not shown, a shift lens included in the shift lens unit 103 is fixed to the driving magnet 502. The shift lens can be displaced in a direction perpendicular to the optical axis, and is driven in a direction to correct a shake of a captured image generated by a shake of the digital camera.

  Reference numeral 501 denotes a Hall element that detects the magnetic flux at the magnetization boundary portion of the driving magnet 502, and thereby indirectly detects the position of the shift lens that is displaced integrally with the driving magnet 502. The Hall element 501 is actually composed of a Hall element 209 for pitch direction and a Hall element 210 for yaw direction, which will be described later with reference to FIG.

  Reference numeral 503 denotes a fixed coil fixed to the digital camera body. A current is passed through the fixed coil 503, and as a result, an electromagnetic force generated between the fixed magnet 503 and the driving magnet 502 is used. Displace the position.

  FIG. 3 is a block diagram showing an internal configuration of the shift lens drive control unit 104 shown in FIG.

  Reference numeral 201 denotes a pitch direction gyro unit, which detects vibration in the vertical direction (pitch direction) of a digital camera in a normal posture (an attitude in which the length direction of the image frame substantially coincides with the horizontal direction). Reference numeral 202 denotes a yaw direction gyro unit that detects vibration in the horizontal direction (yaw direction) of a digital camera in a normal posture. Reference numerals 203 and 204 denote anti-vibration control units in the pitch direction and yaw direction, respectively, which perform anti-vibration control and shift lens position control according to the situation. Reference numerals 205 and 206 respectively denote PID units, which obtain control amounts from corrected position control signals in the pitch direction and yaw direction, and position signals indicating positions in the pitch direction and yaw direction of the shift lens, and output position command signals. To do. Reference numerals 207 and 208 respectively denote drive units that drive the shift lens unit 103 based on position command signals sent from the PID units 205 and 206, respectively. Reference numerals 209 and 210 denote Hall elements, which detect the positions of the shift lens unit 103 in the pitch direction and the yaw direction, respectively.

  Reference numerals 211 and 212 denote AD converters that convert analog position signals from the hall elements 209 and 210 in the pitch direction and the yaw direction, respectively, into digital position signals. Here, the position command signals from the PID units 205 and 206 are negatively fed back to the digital position signals in the pitch direction and yaw direction from the AD converters 211 and 212, respectively. In other words, reference numerals 213 and 214 denote phase compensators that advance the phase of each position command signal from the PID units 205 and 206 by a predetermined amount (details will be described later). Reference numerals 215 and 216 denote feedback amount adjusters that adjust feedback amounts to be negatively fed back to the digital position signals in the pitch direction and yaw direction from the AD converters 211 and 212, respectively. This adjustment is performed so that the output signals of the PID units 205 and 206 and the false position signals (described later in detail) included in the output signals from the Hall elements 209 and 210 have the same magnitude.

  FIG. 4 is a block diagram illustrating an internal configuration of the image stabilization control unit 203. Note that the image stabilization control unit 204 also has the same internal configuration as the image stabilization control unit 203, and the description of the image stabilization control unit 204 is omitted.

  In FIG. 4, reference numeral 301 denotes an AD converter that converts a shake information signal (angular velocity signal) from the pitch direction gyro section 201 into a digital signal. Reference numeral 302 denotes a high-pass filter (HPF), which is a filter capable of changing the cutoff frequency for cutting the DC component. Reference numeral 303 denotes a phase lead filter (PLF) whose phase can be changed. Reference numeral 304 denotes a high-pass filter (HPF) capable of changing the cutoff frequency. A low-pass filter (LPF) 305 is a filter for converting an angular velocity signal into an angle signal. A cut-off switching unit 306 changes the cut-off frequency of the HPF 304 according to the amount of shake.

  The shake information signal (angular velocity signal) input to the image stabilization control unit 203 is subjected to a series of filter processes and is input to the PID unit 205 as a corrected position control signal.

  FIG. 5 is a block diagram showing the internal configuration of the PID unit 205. Note that the PID unit 206 also has the same internal configuration as the PID unit 205, and a description of the PID unit 206 is omitted.

  In FIG. 5, 401 is an integral compensator (Ki), 402 is a proportional compensator (Kp), and 403 is a differential compensator (Kd).

  Although the PID unit 205 performs PID control, the PID unit 205 may perform PD control, or PID control and PD control may be switched according to shooting conditions.

  Next, shift lens position control will be described.

  The shift lens drive control unit 104 displaces the driving magnet 502 fixed to the shift lens of the shift lens unit 103 based on shake information signals (angular velocity signals) from the gyro units 201 and 202 in the pitch direction and the yaw direction. . That is, basically, the position of the driving magnet 502 is detected by the Hall elements 209 and 210, and each position signal is sent to the PID units 205 and 206. On the other hand, the image stabilization control units 203 and 204 receive a correction position control signal for correcting image shake based on the degree of shake of the digital camera body detected by the gyro units 201 and 202 in the pitch direction and yaw direction. Output to 205 and 206, respectively. In the PID units 205 and 206, feedback position control is performed on the driving magnet 502 via the drive units 207 and 208 so that each position signal converges to each corrected position control signal.

  In the shift lens drive control unit 104 having such a configuration, the magnetic flux generated by the fixed coil 503 is detected by the Hall elements 209 and 210, and a false position signal is output. The magnitude of the false position signal is proportional to the magnitude of the magnetic flux generated by the fixed coil 503. The magnitude of the magnetic flux generated by the fixed coil 503 is proportional to the amount of current flowing through the fixed coil 503. Further, the amount of current flowing through the fixed coil 503 is proportional to the magnitude of the output signal from the PID units 205 and 206. Because of this relationship, if the output signals from the PID units 205 and 206 are negatively fed back with respect to the output signals from the Hall elements 209 and 210, the false signals included in the output signals from the Hall elements 209 and 210, respectively. The position signal is canceled.

  In the shift lens drive control unit 104 configured as described above, the processing performed by the image stabilization control units 203 and 204, the PID units 205 and 206, the phase compensation units 213 and 214, and the feedback amount adjusters 215 and 216 is digital computation. Is done. For this reason, as the frequency of the signal to be processed increases, the time required for the digital arithmetic processing becomes relatively large with respect to the period of the signal to be processed, and the phase delay of the output signals of the PID units 205 and 206 as the feedback amount becomes remarkable. become. As a result, a phase shift occurs between the false position signal included in the output signals from the Hall elements 209 and 210 and the output signals of the PID units 205 and 206, and the false position signal cannot be canceled.

  Therefore, the phase compensation units 213 and 214 perform phase compensation for compensating for the phase delay caused by the digital arithmetic processing on the output signals of the PID units 205 and 206. Thereby, the phase shift between the false position signal included in the output signals from the Hall elements 209 and 210 and the output signals of the PID units 205 and 206 is eliminated.

  Thus, in the above embodiment, the influence of the false position signal generated by the excitation of the fixed coil 503 can be reduced, the stability of the feedback control can be improved, and the vibration noise can be reduced.

  In particular, the hall element detection dedicated magnet is not separately prepared, and the yoke is not attached so that the magnetic field of the drive magnet and the drive coil does not leak to the outside. And effective.

[Other Embodiments]
Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus. It is also achieved by reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. An optical disc such as RW or DVD + RW, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) or the like running on the computer based on the instruction of the program code. Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Furthermore, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the expanded function is based on the instruction of the program code. This includes a case where a CPU or the like provided on the expansion board or the expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows the structure of the digital camera containing the drive control apparatus which concerns on one embodiment of this invention. It is a figure which shows the drive mechanism of a shift lens unit. It is a block diagram which shows the internal structure of the shift lens drive control part shown in FIG. It is a block diagram which shows the internal structure of a vibration proof control part. It is a block diagram which shows the internal structure of a PID part. It is a block diagram which shows the basic control circuit structure of the drive control apparatus shown by patent document 1. FIG.

Explanation of symbols

103 Shift lens unit (driven body)
104 Shift lens drive control unit 117 Control unit 203 Anti-vibration control unit (target position generation means)
204 Anti-vibration control unit (target position generating means)
205 PID section (drive control means)
206 PID section (drive control means)
213 Phase compensation unit (feedback means)
214 Phase compensation unit (feedback means)
215 Feedback amount adjuster (feedback means)
216 Feedback amount adjuster (feedback means)
501 Hall element (position detection means)
502 Driving magnet (magnetic material)
503 Fixed coil (energized energizer)

Claims (6)

A magnetic body that can be displaced integrally with the driven body;
An energized exciter that is excited by energization and displaces the magnetic body by electromagnetic force;
Position detecting means for detecting a magnetic flux of the magnetic body and outputting a position signal indicating a position where the driven body exists;
Target position generating means for generating a target position signal representing a target position where the driven body should exist;
Based on the difference between the position signal output by the position detection means and the target position signal generated by the target position generation means, a position command signal for controlling the position of the driven body is generated, and Drive control means for outputting to the energized exciter;
The position command signal generated by the drive control means is negatively fed back to the position signal output by the position detection means, and the position detection means outputs a false signal generated by the magnetic flux generated by the energized exciter. It possesses a feedback means for canceling the position signal,
The return means is
Digital processing performed in the target position generation unit, the drive control unit, and the feedback unit in the position command signal generated by the drive control unit, which is a phase lag with respect to the position signal output by the position detection unit Phase compensation means for compensating for the phase lag associated with
And a feedback amount adjusting means for adjusting the level of the position command signal generated by the drive control means with respect to the level of the position signal output by the position detecting means . The drive control apparatus according to claim 1, wherein the phase compensation unit performs phase advance compensation. The drive control device according to claim 1, wherein the phase delay accompanying the digital processing is caused by a time required for the digital arithmetic processing. Said drive control means, said proportional compensation based on the difference, integral compensation, and the drive control of any one of claims 1 to 3 carried out differential compensation and generates the position command signal apparatus. A drive control method executed by a drive control device including a magnetic body that can be displaced integrally with a driven body, and an energization excitation body that is excited by energization and displaces the magnetic body by electromagnetic force,
A position detection step of detecting a magnetic flux of the magnetic body and outputting a position signal indicating a position of the driven body;
A target position generating step for generating a target position signal representing a target position where the driven body should exist;
Based on the difference between the position signal output in the position detection step and the target position signal generated in the target position generation step, a position command signal for controlling the position of the driven body is generated, and A drive control step for outputting to the energized exciter;
The position command signal generated in the drive control step is negatively fed back to the position signal output in the position detection step, and a false signal output from the position detection means due to the magnetic flux generated by the energized exciter is generated. possess a feedback step of canceling a location signal,
The return step includes
Digital processing performed in the target position generation step, the drive control step, and the feedback step in the position command signal generated by the drive control step, which is a phase lag with respect to the position signal output by the position detection step A phase compensation step for compensating for the phase lag associated with
And a feedback adjustment step for adjusting the level of the position command signal generated by the drive control step with respect to the level of the position signal output by the position detection step . A drive control method applied to a drive control device including a magnetic body that can be displaced integrally with a driven body, and an energization excitation body that is excited by energization and displaces the magnetic body by electromagnetic force. A program to be executed,
The drive control method includes:
A position detection step of detecting a magnetic flux of the magnetic body and outputting a position signal indicating a position of the driven body;
A target position generating step for generating a target position signal representing a target position where the driven body should exist;
Based on the difference between the position signal output in the position detection step and the target position signal generated in the target position generation step, a position command signal for controlling the position of the driven body is generated, and A drive control step for outputting to the energized exciter;
The position command signal generated in the drive control step is negatively fed back to the position signal output in the position detection step, and a false signal output from the position detection means due to the magnetic flux generated by the energized exciter is generated. possess a feedback step of canceling a location signal,
The return step includes
A phase delay associated with digital processing performed in the target position generation step, the drive control step, and the feedback step in the position command signal generated in the drive control step with respect to the position signal output in the position detection step. A phase compensation step to compensate;
A feedback amount adjusting step for adjusting a level of the position command signal generated by the drive control step with respect to a level of the position signal output by the position detecting step .

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