JP2021061710A - Driving device, imaging apparatus, method for controlling driving device, and program - Google Patents

Abstract

To provide a driving device that can achieve drive with high output and high accuracy.SOLUTION: A driving device has: a plurality of vibrators (1052, 1053); at least one movable body (1051) that is in contact with the plurality of vibrators; drive signal generation units (1128, 1129) that generate driving signals applied to the plurality of vibrators to move the movable body; a target position setting unit (1123) that sets a target position of the movable body; a position detection unit (1056) that detects a position of the movable body; drive control units (1125, 1126) that determine waveforms of the driving signals on the basis of a difference between the target position set by the target position setting unit and the position of the movable body detected by the position detection unit; a control system setting unit (1124) that sets a control system for the drive control units; and a mode switching unit (1132) that switches a driving mode of the plurality of vibrators on the basis of the control system for the drive control unit.SELECTED DRAWING: Figure 2

Description

The present invention relates to a driving device for a vibrating actuator including a plurality of vibrating bodies and one moving body.

Conventionally, a vibrating actuator is known in which a piezoelectric element (oscillator) is pressed against an elastic body or a high friction material by a spring or the like, and a plurality of voltage waveforms are applied to excite vibration in the oscillator to obtain a thrust. .. When controlling such a vibrating actuator, the vibration state is changed by changing the amplitude, duty ratio, frequency, or phase difference between the plurality of voltage waveforms applied to the vibrator, and the thrust is changed. And speed control. The vibrating actuator can be miniaturized while having high torque and high responsiveness, and a large torque can be obtained by combining a plurality of vibrating actuators. However, when one moving body is driven in the same direction by using a plurality of vibration actuators, a large torque can be obtained, but highly accurate positioning drive is difficult.

Patent Document 1 describes a first drive mode in which a plurality of oscillators perform an elliptical motion, one of the plurality of oscillators performs an elliptical motion, and the other oscillators linearly move in the direction of pressurization. A vibration wave motor capable of switching between a second drive mode for exercising is disclosed.

JP-A-2017-60279

However, in the vibration wave motor disclosed in Patent Document 1, since at least one oscillator always performs elliptical motion, it is difficult to realize high output and high precision drive.

Therefore, an object of the present invention is to provide a drive device, an image pickup device, a control method for the drive device, and a program capable of realizing high-output and high-precision drive.

The drive device as one aspect of the present invention includes a plurality of vibrating bodies, at least one moving body in contact with the plurality of vibrating bodies, and a driving signal applied to the plurality of vibrating bodies to move the moving body. The drive signal generation unit that generates the above, the target position setting unit that sets the target position of the moving body, the position detection unit that detects the position of the moving body, and the target position set by the target position setting unit. A drive control unit that determines the waveform of the drive signal based on the difference from the position of the moving body detected by the position detection unit, a control method setting unit that sets the control method of the drive control unit, and the above. Based on the control method of the drive control unit, it has a mode switching unit for switching the drive mode of the plurality of vibrating bodies.

The driving device as another aspect of the present invention includes a plurality of vibrating bodies, at least one moving body in contact with the plurality of vibrating bodies, and a drive applied to the plurality of vibrating bodies to move the moving body. A drive signal generation unit that generates a signal, a target position setting unit that sets a target position of the moving body, a position detection unit that detects the position of the moving body, and the target position set by the target position setting unit. Based on the difference between the position and the position of the moving body detected by the position detection unit, the drive control unit that determines the waveform of the drive signal, and the difference or the control amount calculated from the difference. It has a mode switching unit for switching the drive mode of a plurality of vibrating bodies.

The imaging device as another aspect of the present invention includes an imaging unit and the driving device.

The method of controlling the drive device as another aspect of the present invention is a method of controlling the drive device having a plurality of vibrating bodies and at least one moving body in contact with the plurality of vibrating bodies, and the moving body. A step of setting the target position of the moving body, a step of detecting the current position of the moving body, a step of calculating the difference between the target position and the current position, and applying to the plurality of vibrating bodies based on the difference. A step of determining the waveform of the drive signal for moving the moving body, a step of setting a control method for determining the waveform of the drive signal, and a step of setting the control method of the plurality of vibrating bodies. It has a step of switching the drive mode.

A method of controlling a drive device as another aspect of the present invention is a method of controlling a drive device having a plurality of vibrating bodies and at least one moving body in contact with the plurality of vibrating bodies. A step of setting the target position of the above, a step of detecting the current position of the moving body, a step of calculating the difference between the target position and the current position, and applying to the plurality of vibrating bodies based on the difference. It has a step of determining the waveform of the drive signal for moving the moving body, and a step of switching the drive mode of the plurality of vibrating bodies based on the difference or the control amount calculated from the difference.

A program as another aspect of the present invention causes a computer to execute the control method of the drive device.

Other objects and features of the present invention will be described in the following embodiments.

According to the present embodiment, it is possible to provide a drive device, an image pickup device, a control method of the drive device, and a program capable of realizing high-output and high-precision drive.

It is a block diagram of the image pickup apparatus in this embodiment. It is a block diagram of the pan rotation unit and the lens barrel rotation drive part in this embodiment. It is sectional drawing of the 1st oscillator in this embodiment. It is a figure which shows the relationship between the drive frequency of the 1st oscillator and the drive speed of a rotating part in this embodiment. It is a flowchart which shows the control method of the drive device in this embodiment. It is a figure which shows the relationship between the control amount of each oscillator in this embodiment and each of a phase difference and a frequency. It is a flowchart which shows the control method of the drive device in this embodiment. It is a figure which shows the relationship between the control amount of the main oscillator and the sub oscillator of a high precision drive mode in this embodiment, a phase difference and a frequency. It is a figure which shows the relationship between the control amount of the main oscillator and the sub oscillator of a high output mode in this embodiment, a phase difference and a frequency.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, with reference to FIG. 1, an imaging device including a driving device for a vibration actuator according to the present embodiment will be described. FIG. 1 is a block diagram of the image pickup apparatus 100. In the present embodiment, the driving device for the vibration actuator is mounted on the image pickup device 100, but may be mounted on an electronic device other than the image pickup device 100.

The lens barrel 101 includes a zoom unit 102, a focus unit 103, and an imaging unit 115. The zoom unit 102 includes a zoom lens for changing the magnification of the angle of view, and is driven and controlled by the zoom drive control unit 113. The focus unit 103 includes a focus lens for adjusting the focus, and is driven and controlled by the focus drive control unit 114. The image pickup unit 115 includes an image pickup element such as a CMOS sensor, photoelectrically converts an optical image (subject image) formed via an image pickup optical system including a zoom lens and a focus lens, and outputs image data. That is, the image pickup unit 115 receives the light incident on the image pickup device through the image pickup optical system, and generates analog image data as charge information according to the amount of the light. Further, the imaging unit 115 has an A / D converter and converts analog image data into digital image data.

The image processing unit 106 performs image processing such as distortion correction, white balance adjustment, and color interpolation processing on the digital image data, and outputs the digital image data after the image processing. Further, the image processing unit 106 converts the digital image data into a video signal (video signal) conforming to a format such as NTSC or PAL, and supplies the digital image data to the image memory 107. The image deformation unit 108 outputs the video signal stored in the image memory 107 based on the image deformation amount calculated by the control unit 110. The image recording unit 109 records the video signal output from the image deformation unit 108 on a recording medium such as a non-volatile memory.

The lens barrel rotation drive unit 112 drives the tilt rotation unit 104 and the pan rotation unit 105, respectively, and drives the lens barrel 101 in the tilt direction and the pan direction, respectively. The shaking detection unit 116 includes, for example, an angular velocity meter (gyro sensor) that detects the angular velocity of the imaging device 100 in the three axial directions, and detects the shaking of the imaging device 100. The power supply unit 117 supplies electric power to each unit of the image pickup apparatus 100 such as the control unit 110. The operation unit 111 is used for the user to give an instruction to the control unit 110 of the image pickup device 100, and includes a power button and a button for changing the setting of the image pickup device 100. When the power button is operated, power is supplied from the power supply unit 117, and the image pickup apparatus 100 is activated. The control unit 110 controls the entire system of the image pickup apparatus 100.

Next, with reference to FIG. 2, the pan rotation unit 105 and the lens barrel rotation drive unit 112 constituting the drive device will be described. FIG. 2 is a block diagram of the pan rotation unit 105 and the lens barrel rotation drive unit 112 (together, a drive device). The tilt rotation unit 104 is configured in the same manner as the pan rotation unit 105 except that the rotation drive axis is different, and constitutes a part of the drive device. In FIG. 2, a high-precision drive mode (first mode) that prioritizes controllability and a high-output mode (second mode) that prioritizes output are based on the difference (deviation amount) between the target position and the current position when controlling the pan position. The switching with (mode) of) will be described.

In the pan rotation unit 105, the rotating unit 1051 rotates the lens barrel 101 in the pan direction. The first oscillator 1052 and the second oscillator 1053 (that is, a plurality of vibrating bodies) have an electromechanical energy conversion element and are actuators (vibration actuators) for rotating the rotating portion 1051 in the pan direction. .. The rotating unit 1051 is at least one moving body that comes into contact with each of the first oscillator 1052 and the second oscillator 1053.

Here, the configuration of the first oscillator 1052 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the first oscillator 1052, showing the concept of the driving principle of the vibrating actuator. In FIG. 3, the x-axis shows the moving direction (feeding direction) of the rotating portion 1051, and the y-axis shows the direction orthogonal to the moving direction of the rotating portion 1051 (pushing direction). 301a and 301b are electrodes. 302a and 302b are piezoelectric elements. Reference numeral 303 is a stator. When driving the rotating unit 1051, two-phase periodic voltage waveforms having different phases supplied from the first drive circuit 1054, which will be described later, are applied to the electrodes 301a and 301b, respectively. When a periodic voltage waveform is applied to the electrode 301, the piezoelectric elements 302a and 302b expand and contract due to the inverse piezoelectric effect, and two types of standing waves are generated in the stator 303. By combining two types of standing waves, a substantially elliptical motion is generated at the contact portion between the stator 303 and the rotating portion 1051.

Reference numeral 304 denotes a locus of elliptical vibration generated at a point P of the stator 303 when a two-phase sinusoidal voltage waveform having a predetermined phase difference is applied to the electrodes 301a and 301b. Reference numeral 305 is a locus of elliptical vibration generated when the phase difference of the two-phase periodic voltage waveform is increased with respect to the voltage waveform indicated by the locus 304. The elliptical vibration shown by the locus 305 has a larger feed direction component than the elliptical vibration shown by the locus 304. By changing the phase difference of the two-phase periodic voltage waveform in this way, the ratio of the component in the feed direction and the component in the push-up direction can be changed, so that the drive speed of the rotating portion 1051 can be changed. Become.

Reference numeral 306 is a locus of elliptical vibration generated when the frequency (driving frequency) of the two-phase periodic voltage waveform is lowered (approached to the resonance frequency of the first oscillator 1052) with respect to the locus 305. The elliptical vibration indicated by the locus 306 has a larger component in the moving direction and a component in the pushing direction than the elliptical vibration shown in the locus 305. By changing the frequency in this way, the driving speed of the rotating unit 1051 can also be changed. The drive speed of the second oscillator 1053 can also be changed with the same configuration as that of the first oscillator 1052.

Next, with reference to FIG. 4, the relationship between the drive frequency of the first oscillator 1052 and the drive speed of the rotating unit 1051 will be described. FIG. 4 is a diagram showing the relationship (FN characteristic) between the drive frequency of the first oscillator 1052 and the drive speed of the rotating unit 1051. In FIG. 4, the horizontal axis represents the driving frequency and the vertical axis represents the driving speed.

Reference numeral 401 denotes an FN characteristic when a voltage waveform having a phase difference (30 °) corresponding to the locus 304 of the elliptical vibration generated at the point P is applied. Reference numeral 402 denotes an FN characteristic when a voltage waveform having a phase difference (90 °) corresponding to the locus 305 of the elliptical vibration generated at the point P is applied. Fr0 is the resonance frequency of the first oscillator 1052, Fmin is the lower limit of the frequency range used for frequency control, and Fmax is the upper limit of the frequency range used. When controlling the driving speed of the rotating unit 1051, the speed is controlled to be a predetermined value by changing the phase difference or the frequency.

The vibration actuator is generally controlled by using a vibration frequency higher than the resonance frequency. When performing speed control, both the method of fixing the phase difference and changing the vibration frequency (frequency control mode), the method of fixing the vibration frequency and changing the phase difference (phase difference control mode), or both the vibration frequency and the phase difference. There is a way to change (frequency and phase difference control mode). 403 is the speed when the phase difference is 30 ° and the frequency is Fmax, and 404 is the speed when the phase difference is 90 ° and the frequency is Fmin. In the phase difference control mode, the drive speed of the first oscillator 1052 is controlled by fixing the frequency Fmax and changing the phase difference from 0 ° to 90 °. On the other hand, in the frequency control mode, the driving speed of the first oscillator 1052 is controlled by fixing the phase difference to 90 ° and changing the frequency from Fmax to Fmin. The phase difference control mode has a low output but enables highly accurate positioning, and is suitable when high stop position accuracy is required or when a minute drive is performed. On the other hand, the frequency control mode is suitable for driving the rotating portion 1051 at high speed due to its high output, or when the load on the first oscillator 1052 increases due to a low temperature environment or deterioration of durability of the moving portion. There is.

In FIG. 2, 1056 is a position sensor (position detection unit) that detects the rotation position of the rotation unit 1051. The position sensor 1056 uses the light receiving unit to transmit the reflected light of the light emitted from the light emitting unit to the pattern engraved on the optical scale with respect to the optical scale mounted integrally with the rotating unit 1051. Detect as. The 1121 is an A / D converter (ADC) for converting an analog electric signal detected by the position sensor 1056 into a digital electric signal. The 1122 is a position calculation unit for obtaining the rotation position of the rotation unit 1051 from the sensor information digitized by the ADC 1121.

Reference numeral 1123 is a target position setting unit that sets a target position (target rotation position) of the pan based on a rotation instruction from the operation unit 111. The 1124 is a PID calculation unit that performs PID calculation based on the difference (deviation) between the target position of the rotation unit 1051 set in the target position setting unit 1123 and the position of the rotation unit 1051 obtained by the position calculation unit 1122. .. Further, the PID calculation unit 1124 sets the control method of the first conversion unit 1125 and the second conversion unit 1126, which will be described later, based on the command of the control unit 110.

Reference numerals 1125 and 1126 are a first conversion unit and a second conversion unit (control amount-phase difference, frequency conversion unit) that convert the control amount calculated by the PID calculation unit 1124 into the phase difference and frequency of the voltage waveform, respectively. .. The first conversion unit 1125 and the second conversion unit 1126 set the difference (deviation) between the target position set by the target position setting unit 1123 and the position (current position) of the rotating unit 1051 detected by the position sensor 1056. Based on this, it is a drive control unit that determines the waveform of the drive signal.

Reference numeral 1132 is a drive mode setting unit (mode switching unit) for setting the drive modes of the first oscillator 1052 and the second oscillator 1053. The drive mode setting unit 1132 switches the drive modes of the first oscillator 1052 and the second oscillator 1053 based on the control methods of the first conversion unit 1125 and the second conversion unit 1126. For example, the drive mode setting unit 1132 may use a high-precision drive mode (first mode) that requires high-precision positioning drive for the rotating unit 1051, a high-output mode (second mode) that gives priority to output, or a high-precision drive. Set one of the normal drive modes between the mode and the high output mode. The first conversion unit 1125 and the second conversion unit 1126 perform phase difference control and frequency control according to the drive mode set by the drive mode setting unit 1132 and the control amount obtained by the PID calculation unit 1124. Switch.

Reference numeral 1131 is a drive counter, and counts up the count value for each drive of the first oscillator 1052 and the second oscillator 1053 in phase difference control or frequency control, respectively. The drive counter 1131 also counts and stores the number of drives for each of the main and sub roles of the first oscillator 1052 and the second oscillator 1053. Reference numeral 1127 is a main-sub switching unit, and the first oscillator 1052 and the second oscillator 1052 and the second oscillator are counted according to the count values counted for each drive of the first oscillator 1052 and the second oscillator 1053 by the drive counter 1131. Switch the main and sub roles of 1053.

Reference numerals 1128 and 1129 are a first drive signal generation circuit and a second drive signal generation circuit that generate voltage waveforms (drive signals) applied to the first oscillator 1052 and the second oscillator 1053, respectively. The first drive signal generation circuit 1128 and the second drive signal generation circuit 1129 are applied to the first oscillator 1052 and the second oscillator 1053 to generate a drive signal for moving the rotating unit 1051. It is a generator.

1054 and 1055 are a first drive circuit and a second drive circuit, respectively. The first drive circuit 1054 and the second drive circuit 1055 transfer the voltage waveforms generated by the first drive signal generation circuit 1128 and the second drive signal generation circuit 1129 to the first vibrator 1052 and the second vibration. Amplifies and signals are converted into a predetermined voltage waveform that drives the child 1053.

Next, with reference to FIG. 5, a method of determining the phase difference and frequency of the voltage waveform (drive signal) applied to the first vibrator 1052 and the second vibrator 1053 from the setting of the target position of the rotating unit 1051. (Control method of drive device) will be described. FIG. 5 is a flowchart showing a control method of the drive device. Each step of FIG. 5 is mainly executed by the tilt rotation unit 104, the pan rotation unit 105, or the lens barrel rotation drive unit 112 based on the command of the control unit 110.

First, in step S501, the target position setting unit 1123 sets the target position with respect to the PID calculation unit 1124. If the target position is not specified by the control unit 110, or if the target position has not changed from the current position, the PID calculation unit 1124 holds the previously set target position. Subsequently, in step S502, the PID calculation unit 1124 acquires the current position of the rotation unit 1051 from the position calculation unit 1122. Subsequently, in step S503, the PID calculation unit 1124 calculates the PID so that the difference between the target position and the current position of the rotating unit 1051 becomes small (preferably, the difference between the target position and the current position becomes 0). To calculate the control amount.

Subsequently, in step S504, the drive mode setting unit 1132 determines the control method of the main oscillator and the sub oscillator. That is, the drive mode setting unit 1132 switches between the high-precision drive mode (first mode) and the high output mode (second mode) based on the control amount obtained by the PID calculation.

Here, with reference to FIG. 6, the relationship between the control amount and the frequency and phase difference of the voltage waveform will be described. FIG. 6 is a diagram showing the relationship between the control amounts of the main oscillator and the sub oscillator, the phase difference, and the frequency in the normal drive mode. In FIG. 6A, the horizontal axis represents the control amount and the vertical axis represents the frequency. In FIG. 6B, the horizontal axis shows the control amount and the vertical axis shows the phase difference.

In FIG. 6A, the solid line 601 indicates the frequency of the voltage waveform applied to the main oscillator, and the broken line 602 indicates the frequency of the voltage waveform applied to the sub oscillator. In FIG. 6B, the solid line 603 shows the phase difference of the voltage waveform applied to the main oscillator, and the broken line 604 shows the phase difference of the voltage waveform applied to the sub oscillator. The voltage waveform applied to the oscillator switches between phase difference control and frequency control in five patterns based on the control amount calculated by the PID calculation unit 1124.

When the control amount is 0 or more and less than th1, the main oscillator fixes the frequency to Fmax and the sub oscillator fixes the frequency to Fmax and the phase difference to Pmin regardless of the control amount. When the control amount is th1 or more and less than th2, the main oscillator is frequency-controlled, and the sub-oscillator fixes the frequency to Fmax and the phase difference to Pmin regardless of the control amount. When the control amount is th2 or more and less than th3, the main oscillator fixes the frequency to Fmin and the phase difference to Pmax regardless of the control amount, and the sub oscillator fixes the frequency to Fmax and drives by phase difference control. When the control amount is th3 or more and less than th4, the main oscillator fixes the frequency to Fmin and the phase difference to Pmax regardless of the control amount, and the sub oscillator fixes the phase difference to Pmax and drives by frequency control. When the control amount is th4 or more, the frequencies of both the main oscillator and the sub oscillator are fixed at Fmin and the phase difference is fixed at Pmax for driving.

Subsequently, in step S505, the main-sub switching unit 1127 switches the roles of the main and sub of the first oscillator 1052 and the second oscillator 1053 based on the drive count number of the drive counter 1131. When the number of drive counts since the previous main and sub roles are exchanged is equal to or greater than a predetermined value, the main-sub switching unit 1127 exchanges the roles. On the other hand, if the number of drive counts is less than a predetermined value, the roles are not exchanged. The present embodiment is not limited to this, and the degree of durability deterioration of each oscillator is estimated based on the relationship between the drive frequency and the drive speed of the rotating unit 1051 and the relationship between the drive phase difference and the drive speed. The roles of each oscillator may be interchanged.

Subsequently, in step S506, the first drive signal generation circuit 1128 and the second drive signal generation circuit 1129 generate an appropriate voltage waveform based on the role determined by the main-sub switching unit 1127. And apply to the second transducer 1053. That is, the first drive signal generation circuit 1128 and the second drive signal generation circuit 1129 use the voltage waveforms of the frequency and phase difference determined by the first conversion unit 1125 and the second conversion unit 1126 as the first transducer 1052. And apply to the second transducer 1053.

As described above, when the PID calculation amount is small, such as when the load on the vibrator is small or the drive speed is slow, driving is performed using a small number of vibrators. At this time, since only one oscillator performs elliptical motion and the other oscillators perform linear motion that does not contribute to driving, high-precision driving is possible although the output is low. On the other hand, when the PID control amount is large as in the case where the load is large or the drive speed is high, the number of oscillators is increased for driving. At this time, the controllability is lowered due to the variation in the characteristics of each oscillator, but high output drive is possible.

As described above, according to the drive device of the present embodiment, both high-precision positioning drive and high-torque high-output drive can be achieved at the same time. Further, since the high-precision drive and the high-output drive are switched according to the control amount, efficient drive can be performed in terms of power and durability. Further, by switching the main and sub roles of a plurality of oscillators depending on the drive count and the degree of deterioration of the oscillators, it is possible to avoid a situation in which only one of the oscillators wears.

Next, with reference to FIG. 7, a method of switching between a high precision drive mode (precision priority mode) and a high output mode (output priority mode) according to the mode setting of the imaging device 100 (drive device control method) will be described. .. FIG. 7 is a flowchart showing a control method of the drive device. Each step of FIG. 7 is mainly executed by the tilt rotation unit 104, the pan rotation unit 105, or the lens barrel rotation drive unit 112 based on the command of the control unit 110. Since steps S501 to S506 are common to FIGS. 5 in FIG. 7, only steps S701 to S704 different from those in FIG. 5 will be described.

In step S701, the PID calculation unit 1124 determines whether or not the mode set by the drive mode setting unit 1132 is a high-precision drive mode. If the drive mode is a high-precision drive mode, the process proceeds to step S702. On the other hand, if the drive mode is not the high-precision drive mode, the process proceeds to step S703. The drive mode set by the drive mode setting unit 1132 is switched in conjunction with the state of the image pickup apparatus 100. For example, the drive mode is set to a high-precision mode when vibration isolation by pan-tilt drive, panoramic shooting, time-lapse shooting, subject tracking by pan-tilt operation, when the battery level of the power supply unit is low, or when the power saving mode is set. On the other hand, when the load increases due to low temperature environment, durability deterioration, the output of the oscillator decreases, the subject is lost from the angle of view during positioning (reset) drive when the power is turned on / off, or during subject tracking by pan / tilt operation. In the case of the search drive of, the drive mode is set to the high output mode. In this way, the switching is automatically performed according to the state or mode setting of the image pickup apparatus 100. The present embodiment is not limited to this, and may be switched according to the mode set by the user via the operation unit 111.

FIG. 8 is a diagram showing the relationship between the control amount of the main oscillator and the sub oscillator in the high-precision drive mode, the phase difference, and the frequency. In FIG. 8A, the horizontal axis represents the control amount and the vertical axis represents the frequency. In FIG. 8B, the horizontal axis shows the control amount and the vertical axis shows the phase difference. In FIG. 8A, the solid line 801 indicates the frequency of the voltage waveform applied to the main oscillator, and the broken line 802 indicates the frequency of the voltage waveform applied to the sub oscillator. In FIG. 8B, the solid line 803 shows the phase difference of the voltage waveform applied to the main oscillator, and the broken line 804 shows the phase difference of the voltage waveform applied to the sub oscillator. The voltage waveform applied to the oscillator switches between phase difference control and frequency control in three patterns based on the control amount calculated by the PID calculation unit 1124 (with th5 and th6 as boundaries).

When the mode set by the drive mode setting unit 1132 is a high-precision mode, in step S702, as shown in FIG. 8, the sub oscillator fixes the frequency to Fmax and the phase difference to Pmin regardless of the control amount. Only the main oscillator performs phase difference control or frequency control. Further, the main oscillator may be fixed at the frequency Fmax and controlled only by the phase difference control without changing the phase difference control to the frequency control according to the control amount.

In step S703, the PID calculation unit 1124 determines whether or not the drive mode set by the drive mode setting unit 1132 is a high output mode. When the drive mode is the high output mode, the process proceeds to step S704. On the other hand, when the drive mode is not the high output mode, the process proceeds to step S504, and the PID calculation unit 1124 controls in the normal control mode.

FIG. 9 is a diagram showing the relationship between the control amount of the main oscillator and the sub oscillator in the high output mode, the phase difference, and the frequency. In FIG. 9A, the horizontal axis represents the control amount and the vertical axis represents the frequency. In FIG. 9B, the horizontal axis shows the control amount and the vertical axis shows the phase difference. In FIG. 9A, the solid line 901 shows the frequency of the voltage waveform applied to the main oscillator and the sub oscillator. In FIG. 9B, the solid line 902 shows the phase difference of the voltage waveforms applied to the main oscillator and the sub oscillator.

When the mode set by the drive mode setting unit 1132 is the high output mode, as shown in FIG. 9, the sub oscillator and the main oscillator are fixed to the phase difference Pmax and the frequency Fmin that maximize the output. Driven. However, the present embodiment is not limited to this, and frequency control may be performed by fixing either one or both oscillators to the phase difference Pmax.

As described above, when the load is small, a small number of oscillators are elliptically moved to drive, and when the load is large, many oscillators are elliptically moved to drive. Since the load torque differs depending on the speed, attitude difference, and temperature, it is possible to realize highly accurate and high-output drive by determining the drive mode of the oscillator to which the traveling wave is applied in consideration of these factors. Further, when the load applied to the vibrator is low, some of the vibration actuators are pushed up and driven, so that the wear of the contact portion between the vibrator and the slider can be reduced. It is also effective in terms of durability because the main and sub roles of the oscillator are changed by the drive count of the oscillator. Further, since the drive mode is selected and driven according to the control amount calculated from the difference between the target position and the current position of the image pickup apparatus 100, the oscillator can always be driven in an appropriate drive mode. In the present embodiment, the mechanism is such that the moving body is rotationally driven, but the mechanism may be such that the vibrator is rotationally driven as a rotor and the moving body is fixed as a stator to move the vibrator.

As described above, in the present embodiment, the drive device has a control method setting unit (control unit 110, PID calculation unit 1124) and a mode switching unit (drive mode setting unit 1132). The control method setting unit sets the control method of the drive control unit (first conversion unit 1125, second conversion unit 1126). The mode switching unit switches the drive mode of a plurality of vibrating bodies based on the control method of the drive control unit.

Preferably, the mode switching unit switches the drive mode from the first mode to the second mode or from the second mode to the first mode based on the setting of the control method. More preferably, the setting of the control method setting unit has a first setting of accuracy priority and a second setting of output priority. More preferably, the mode switching unit switches the drive mode to the first mode when the setting of the control method setting unit is the first setting, and drives the mode switching unit when the setting of the control method setting unit is the second setting. Switch the mode to the second mode.

Preferably, the setting of the control method setting unit is switched based on the operating state of the drive device. More preferably, the driving device has a moving image recording means (a storage unit such as an image memory 107). The operating state is a state relating to whether or not a moving image is being recorded by the moving image recording means. When the moving image is being recorded by the moving image recording means, the setting of the control method setting unit is the first setting, and when the moving image is not being recorded by the moving image recording means, the setting of the control method setting unit is the second setting. Further, preferably, the driving device has a subject tracking means (control unit 110) that tracks the subject by moving the moving body. The operating state is a state relating to whether or not the subject tracking means is tracking the subject. When the subject is being tracked by the subject tracking means, the setting of the control method setting unit is the first setting, and when the subject is not being tracked by the subject tracking means, the setting of the control method setting unit is the second setting. Further, preferably, the driving device has a battery remaining amount detecting means (control unit 110) for detecting the remaining amount of the battery. The operating state is a state related to whether or not the remaining battery level detected by the battery remaining amount detecting means is less than a predetermined value. When the remaining battery level is less than the predetermined value, the setting of the control method setting unit is the first setting, and when the remaining battery level is more than the predetermined value, the setting of the control method setting unit is the second setting. Further, preferably, the drive device has a power saving mode setting means (control unit 110). The operating state is a state related to whether or not the power saving mode is set by the power saving mode setting means. When the power saving mode is set by the power saving mode setting means, the setting of the control method setting unit is the first setting, and when the power saving mode is not set by the power saving mode setting means, the control method setting unit The setting of is the second setting.

Further, in the present embodiment, the mode switching unit is based on the difference between the target position set by the target position setting unit and the position of the moving body detected by the position detection unit, or the control amount calculated from the difference. , Switch the drive mode of multiple vibrating bodies. Preferably, the mode switching unit switches the drive mode from the first mode to the second mode or from the second mode to the first mode based on the control amount calculated from the difference. More preferably, the mode switching unit switches the drive mode to the first mode when the difference is smaller than the predetermined value, and switches the drive mode to the second mode when the difference is larger than the predetermined value.

Preferably, as the drive mode, the mode switching unit has a first mode in which the followability of the position of the moving body with respect to the target position is emphasized and a second mode in which the responsiveness of the position of the moving body with respect to the target position is emphasized. Switch. Further, preferably, the drive control unit switches between a first drive motion in which a plurality of vibrating bodies perform elliptical motion and a second drive motion in which a plurality of vibrating bodies perform linear motion in the direction of the contact surface with the moving body to control the vibrator. Drive. More preferably, two types of standing waves are excited in each of the plurality of vibrating bodies, and the drive control unit changes the elliptic ratio of the elliptical motion by changing the phase difference between the two types of standing waves. The mode 1 and the second mode are switched.

Preferably, the first mode is a drive mode in which at least one of the plurality of vibrating bodies is fixed in linear motion and the elliptical ratio or the size of the ellipse of the elliptical motion of the other oscillator is changed. Also preferably, the second mode is a drive mode in which at least one of the plurality of vibrating bodies is fixed in elliptical motion, and the other oscillator changes the elliptical ratio of elliptical motion or the size of the ellipse. Further, preferably, the oscillator driven by the linear motion fixed in the first mode and the oscillator driven by the elliptical motion fixed in the second mode are different.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It is also possible to realize the processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

According to the present embodiment, in a vibrating actuator composed of a plurality of oscillators and one moving body, the driving efficiency of the vibrating actuator can be improved, and the vibration actuator can be used in a wide range of applications from high output drive to highly accurate positioning drive. Therefore, according to the present embodiment, it is possible to provide a drive device, an image pickup device, a control method of the drive device, and a program capable of realizing high-output and high-precision drive.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

1051 Rotating part (moving body)
1052 First oscillator (vibrating body)
1053 Second oscillator (vibrating body)
1056 Position sensor (position detector)
1123 Target position setting unit 1124 PID calculation unit (control method setting unit)
1125 First conversion unit (drive control unit)
1126 Second conversion unit (drive control unit)
1128 1st drive signal generation circuit (drive signal generator)
1129 Second drive signal generation circuit (drive signal generator)
1132 Drive mode setting unit (mode switching unit)

Claims (22)

With multiple vibrating bodies,
With at least one moving body in contact with the plurality of vibrating bodies,
A drive signal generation unit that is applied to the plurality of vibrating bodies and generates a drive signal for moving the moving body.
A target position setting unit for setting a target position of the moving body and a target position setting unit
A position detection unit that detects the position of the moving body, and
A drive control unit that determines the waveform of the drive signal based on the difference between the target position set by the target position setting unit and the position of the moving body detected by the position detection unit.
A control method setting unit that sets the control method of the drive control unit,
A drive device including a mode switching unit for switching drive modes of the plurality of vibrating bodies based on a control method of the drive control unit. A claim characterized in that the mode switching unit switches the drive mode from the first mode to the second mode or from the second mode to the first mode based on the setting of the control method. Item 2. The drive device according to item 1. The driving device according to claim 2, wherein the setting of the control method setting unit includes a first setting of accuracy priority and a second setting of output priority. The mode switching unit is
When the setting of the control method setting unit is the first setting, the drive mode is switched to the first mode.
The drive device according to claim 3, wherein when the setting of the control method setting unit is the second setting, the drive mode is switched to the second mode. The drive device according to claim 3 or 4, wherein the setting of the control method setting unit is switched based on the operating state of the drive device. It has more video recording means,
The operating state is a state relating to whether or not moving image is being recorded by the moving image recording means.
When a moving image is being recorded by the moving image recording means, the setting of the control method setting unit is the first setting.
The driving device according to claim 5, wherein when the moving image is not being recorded by the moving image recording means, the setting of the control method setting unit is the second setting. It further has a subject tracking means for tracking the subject by moving the moving body.
The operating state is a state relating to whether or not the subject tracking means is tracking the subject.
When the subject is being tracked by the subject tracking means, the setting of the control method setting unit is the first setting.
The driving device according to claim 5, wherein when the subject is not being tracked by the subject tracking means, the setting of the control method setting unit is the second setting. Further having a battery remaining amount detecting means for detecting the remaining battery level,
The operating state is a state relating to whether or not the remaining battery level detected by the battery remaining amount detecting means is less than a predetermined value.
When the remaining battery level is less than the predetermined value, the setting of the control method setting unit is the first setting.
The driving device according to claim 5, wherein when the remaining battery level is larger than the predetermined value, the setting of the control method setting unit is the second setting. It also has a power saving mode setting means,
The operating state is a state relating to whether or not the power saving mode is set by the power saving mode setting means.
When the power saving mode is set by the power saving mode setting means, the setting of the control method setting unit is the first setting.
The driving device according to claim 5, wherein when the power saving mode is not set by the power saving mode setting means, the setting of the control method setting unit is the second setting. With multiple vibrating bodies,
With at least one moving body in contact with the plurality of vibrating bodies,
A drive signal generation unit that is applied to the plurality of vibrating bodies and generates a drive signal for moving the moving body.
A target position setting unit for setting a target position of the moving body and a target position setting unit
A position detection unit that detects the position of the moving body, and
A drive control unit that determines the waveform of the drive signal based on the difference between the target position set by the target position setting unit and the position of the moving body detected by the position detection unit.
A drive device comprising: a mode switching unit for switching a drive mode of the plurality of vibrating bodies based on the difference or a control amount calculated from the difference. The mode switching unit is characterized in that the drive mode is switched from the first mode to the second mode or from the second mode to the first mode based on the control amount calculated from the difference. The driving device according to claim 10. The mode switching unit is
When the difference is smaller than a predetermined value, the drive mode is switched to the first mode.
The drive device according to claim 11, wherein when the difference is larger than the predetermined value, the drive mode is switched to the second mode. As the drive mode, the mode switching unit has a first mode in which the followability of the position of the moving body with respect to the target position is emphasized, and a second mode in which the responsiveness of the position of the moving body with respect to the target position is emphasized. The drive device according to any one of claims 1 to 12, wherein the mode is switched. The drive control unit switches between a first drive motion in which the plurality of vibrating bodies perform elliptical motion and a second drive motion in which the plurality of vibrating bodies perform linear motion in the direction of the contact surface with the moving body to move the vibrating body. The driving device according to claim 13, wherein the driving device is driven. Two types of standing waves are excited in each of the plurality of vibrating bodies.
The claim is characterized in that the drive control unit changes the elliptic ratio of the elliptical motion by changing the phase difference between the two types of standing waves, and switches between the first mode and the second mode. Item 14. The drive device according to item 14. The first mode is characterized in that at least one of the plurality of vibrating bodies is a drive mode in which the linear motion is fixed and the elliptical ratio or the size of the ellipse of the elliptical motion of the other oscillator is changed. The driving device according to any one of 13 to 15. The second mode is characterized in that at least one of the plurality of vibrating bodies is fixed in elliptical motion, and the other oscillator is a drive mode in which the elliptical ratio of elliptical motion or the size of an ellipse is changed. The driving device according to any one of 13 to 16. The invention according to any one of claims 13 to 17, wherein the vibrator driven by the fixed linear motion in the first mode and the vibrator driven by the fixed elliptical motion in the second mode are different. Drive device. Imaging unit and
An imaging device comprising the drive device according to any one of claims 1 to 18. A method for controlling a drive device having a plurality of vibrating bodies and at least one moving body in contact with the plurality of vibrating bodies.
The step of setting the target position of the moving body and
The step of detecting the current position of the moving body and
A step of calculating the difference between the target position and the current position,
Based on the difference, the step of determining the waveform of the drive signal applied to the plurality of vibrating bodies to move the moving body, and
A step of setting a control method for determining the waveform of the drive signal, and
A method for controlling a drive device, which comprises a step of switching a drive mode of the plurality of vibrating bodies based on the control method. A method for controlling a drive device having a plurality of vibrating bodies and at least one moving body in contact with the plurality of vibrating bodies.
The step of setting the target position of the moving body and
The step of detecting the current position of the moving body and
A step of calculating the difference between the target position and the current position,
Based on the difference, the step of determining the waveform of the drive signal applied to the plurality of vibrating bodies to move the moving body, and
A method for controlling a drive device, which comprises a step of switching a drive mode of the plurality of vibrating bodies based on the difference or a control amount calculated from the difference. A program comprising causing a computer to execute the control method of the driving device according to claim 20 or 21.

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