JP2005204373A - Motor controller and light quantity regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller which alleviates a load change at the control time of an object to be controlled, which can remove engaging backlash generated in a mechanism and which can control accurately and stably the object to be controlled. <P>SOLUTION: The motor controller includes: a control quantity set means 13 for setting a target value of the control quantity of the object 12 to be controlled, driven by the motor 11; a drive control quantity calculating means 14 for calculating the drive control quantity from the output of the control quantity set means; a pulse output generating means 15 for generating the pulse of the period shorter than the time constant of the motor; and an adding means 16 for adding the drive control quantity and the pulse output to generate a drive signal for controlling the operation of the object to be controller by finely vibrating the motor within a range without giving an influence to the control quantity of the object to be controlled and to output the drive signal to the motor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motor control device and a light amount adjustment device that control the operation of a controlled object.

  Conventional motor control devices include, for example, the following three motor control devices already proposed by the present applicant.

  As an example 1, the motor is driven and controlled by a drive signal obtained by taking a difference between a light amount control signal serving as a position control amount and a motor speed signal obtained by detecting the rotation speed of the motor, and a light amount adjusting member as a control object is continuously controlled. Japanese Patent Application Laid-Open No. H10-228707 discloses a device that smoothly drives the light source to adjust the light amount corresponding to an appropriate position.

  As an example 2, the optical quantity control signal that is the position control quantity and the pulse output of the pulse generation circuit that generates a pulse with a cycle shorter than the time constant of the motor are added, and the motor is jogged to detect the speed. Patent Document 2 discloses a device that can be driven at a low speed without negative feedback and positions an optical amount adjusting member such as a lens or a light amount adjusting member that is a control target at high speed and with high accuracy.

As an example 3, when the switch of the operation unit that is the control amount setting means is pressed, the drive source that is the motor drives the light quantity variable member that is the control target at high speed to the restriction position, and the desired aperture opening is set and controlled. An apparatus that appropriately varies the amount of light that is an amount is disclosed in Patent Document 3.
Japanese Laid-Open Patent Publication No. 4-223450 (refer to FIGS. 1, 5, etc.) Japanese Patent Laid-Open No. 3-181921 (see FIG. 1, etc.) Japanese Patent Laid-Open No. 9-211531 (see FIG. 1, etc.)

  However, in the above conventional example, a control error due to load fluctuation is likely to occur and has the following problems.

  1) The start of control must suddenly shift from the stopped state to the operating state. For this reason, the load due to friction changes from static friction to dynamic friction, and after standing, grease sticking / surface sticking occurs. A large load fluctuation occurred, resulting in a control error. In particular, a device such as Example 3 that requires a sudden shutter operation has a problem that the first shutter cannot be released.

  2) In an apparatus that requires a smooth operation continuously as in Example 1, the light amount adjustment member that is a control target is caught by dust or burrs, and the light amount corresponding to the position control amount fluctuates due to slight load fluctuations. As a result, a problem that the brightness of the image flickers occurred.

  3) In an apparatus that enables low speed driving by inching drive as in Example 2, the control amount such as the amount of light is varied at the time of inching driving at the target stop position as it is, and a simple low speed is also possible. Since it is driven, fine and smooth speed control is difficult, and noise tends to increase.

  In order to solve the above problem, the invention according to claim 1 is a control amount setting means for setting a target value of a control amount of a control object driven by a motor, and drive control from the output of the control amount setting means. A drive control amount calculating means for calculating the amount; a pulse output generating means for generating a pulse having a cycle shorter than the time constant of the motor; and adding the drive control amount and the pulse output to control the control object. A motor control device comprising: addition means for generating a drive signal for controlling the operation of the controlled object by minutely vibrating the motor within a range that does not affect the amount; and outputting the drive signal to the motor; To do.

  In the above configuration, a pulse output having a cycle shorter than the time constant of the motor is added to the drive control amount, and this is output to the motor as a drive signal to drive the motor, so that the motor becomes the drive control amount. The object to be controlled is operated in accordance with the drive control amount while minutely vibrating in accordance with the pulse output within a range that does not affect.

  According to a second aspect of the present invention, there is provided position detection means for detecting position information of a controlled object driven by a motor, position setting means for setting a target value of the position information, the position information, and the target Position control amount calculation means for calculating a position control amount from a difference in values; speed detection means for detecting speed information of the control object; and drive control for calculating a drive control amount from a difference between the position control amount and the speed information. An amount calculating means, a pulse output generating means for generating a pulse having a cycle shorter than the time constant of the motor, and adding the drive control amount and the pulse output do not affect the control amount of the control object. The motor control device includes an adding means for generating a drive signal for controlling the operation of the control object by minutely vibrating the motor within a range and outputting the drive signal to the motor.

  In the above configuration, a pulse output having a cycle shorter than the time constant of the motor is added to the drive control amount, and this is output to the motor as a drive signal to drive the motor, so that the motor becomes the drive control amount. The object to be controlled is operated in accordance with the drive control amount while minutely vibrating in accordance with the pulse output within a range that does not affect. In addition, since the drive control amount is calculated from the difference between the position control amount and the speed information, the movement of the control object starts to move slowly as the control object approaches the target value, and the control object moves smoothly to the target value. Can be driven to.

  According to the first aspect of the present invention, it is possible to reduce the load fluctuation at the time of control of the control object and to remove the fitting play generated on the mechanism, and to control the control object with high accuracy and stability. The motor control apparatus which can be performed can be provided.

  According to the second aspect of the present invention, it is possible to reduce the load fluctuation at the time of control of the controlled object, and to remove the fitting backlash generated on the mechanism, and to control the object with high accuracy, stability and smoothness. It is possible to provide a motor control device capable of controlling an object.

  The best mode for carrying out the present invention will be described as Example 1 and Example 2 below.

  FIG. 1 is a block diagram illustrating a configuration of a light amount adjusting apparatus including a motor control device according to a first embodiment of the present invention. In the figure, reference numeral 1 denotes a motor for driving the light amount adjusting member 2 based on a drive signal, and includes a rotor magnet 21 and a drive coil 22 which will be described later. Reference numeral 2 denotes a light amount adjusting member that is a control object that is driven by the motor 1 to adjust the amount of incident light. Reference numeral 3 denotes a position detection circuit that linearly detects the rotational position of the rotor magnet 21 of the motor 1 corresponding to the operating position of the light amount adjusting member 2, and includes a hall element 23 and a differential amplifier described later. A light amount detection circuit 4 detects the light amount adjusted by the light amount adjustment member 2 and outputs light amount information to a position setting circuit 5 to be described later. 5 is a position setting for setting a target value for the rotational position of the rotor magnet 21 from the light amount information. A circuit, 6 is a position control amount calculation circuit that compares a set target value with position information and calculates a position control amount from the difference, and 7 is a device that differentiates linear position information and calculates the change amount of the position per unit time. A speed detection circuit that detects speed information, 8 is a subtraction circuit that compares the position control amount and speed information and calculates a drive control amount from the difference, and 9 is a time constant of the motor 1 This is also a pulse output generation circuit for generating a pulse for minutely vibrating the motor in a short cycle. Reference numeral 10 denotes an addition circuit for adding the pulse output and the drive control amount to output a drive signal for the motor 1. As the drive control amount calculation circuit 8 and the addition circuit 10, one addition / subtraction circuit is used as shown in FIG. It is done.

  FIG. 2 is a circuit diagram showing details of the partial circuit shown in FIG. In the figure, reference numeral 21 denotes a rotor magnet which rotates in accordance with an energization current of a drive coil 22 which will be described later and operates the light quantity adjusting member 2 via a transmission member 24, and 22 is energized according to the output of a power amplifier circuit 25 which will be described later. A driving coil that drives the motor 21 and forms part of the components of the motor 1 together with the rotor magnet 21. Reference numeral 23 denotes a Hall element that linearly detects the magnetic force of the rotor magnet 21 and constitutes a position detection circuit together with the differential amplifier. Reference numeral 24 denotes a transmission member that transmits the rotational driving force of the rotor magnet 21 to the light amount adjusting member 2, reference numeral 25 denotes a power amplifier circuit that amplifies the drive signal from the addition circuit 10, and reference numerals 26 and 27 denote addition of the position control amount and the pulse output. This is a resistance for an adder circuit that sets the ratio by the inverse ratio of the resistance.

  In the above configuration, when a drive signal is input to the drive coil 22 of the motor 1, the rotor magnet 21 rotates and the light amount adjusting member 2 is operated via the transmission member 24 to adjust the incident light amount. The light amount adjusted by the light amount adjusting member 2 is detected by the light amount detection circuit 4 and output to the position setting circuit 5 as light amount information. Further, the rotational position of the rotor magnet 21 corresponding to the operating position of the light amount adjusting member 2 is detected by the position detection circuit 3 and output to the position setting circuit 5 as position information.

  In the position setting circuit 5 to which the light quantity information is input, a target value of the light quantity is set from this light quantity information, and a target value of the rotational position of the rotor magnet 21 corresponding to the operating position of the light quantity adjusting member 2 for realizing this is set. Then, the position control amount is calculated by the position control amount calculation circuit 6 from the difference between the set target value of the rotational position and the position information from the position detection circuit 3. Here, the position control amount becomes 0 when the rotational position of the rotor magnet 21 reaches the target value, and at this time, the operating position of the light amount adjusting member 2 and the corresponding light amount reach the target value.

  The position information from the position detection circuit 3 is also input to the speed detection circuit 7, and the speed detection circuit 7 detects the rotation speed of the rotor magnet 21 corresponding to the moving speed of the light quantity adjusting member 2, and the speed is detected. The drive control amount is calculated by the drive control amount calculation circuit 8 from the difference between the speed information and the position control amount from the position control amount calculation circuit 6. Here, the position control amount corresponds to a speed setting signal, and the drive control amount is attenuated in accordance with the rotational speed of the rotor magnet 21, so that the rotational speed is proportional to the position control amount, and the light quantity adjusting member 2 is smoothly supplied. Can be activated. That is, since the position control amount is attenuated as it approaches the target value, the speed setting signal is also set at a low speed, so that it operates slowly, and has high accuracy and smooth positioning control and light amount control without hunting. Become.

  The pulse output generation circuit 9 outputs a pulse for causing the motor 1 to vibrate in a cycle shorter than the time constant of the motor 1, and the adder circuit 10 affects the light output by the pulse output for causing the motor 1 to vibrate slightly. Is added to the drive control amount that smoothly drives the motor 1 to a target value, and is output as a drive signal to the drive coil 22 of the motor 1 via the power amplifier circuit 25. Here, in the first embodiment, the drive control amount calculation circuit 8 and the addition circuit 10 are composed of the same addition / subtraction circuit, and the addition ratio between the position control amount and the pulse output is set by the inverse ratio of the resistors 26 and 27. The pulse output is attenuated to a range that does not affect the light quantity.

  The motor 1 operates the light amount adjusting member 2 based on the drive signal. Specifically, the rotor magnet 21, the transmission member 24, and the light amount adjusting member 2 are vibrated slightly according to the pulse output included in the drive signal. In addition, the load variation in the operation state is reduced, and the light amount adjusting member 2 is smoothly driven and stopped so as to reach the target value according to the drive control amount included in the drive signal.

  Here, the drive signal to which the pulse output is added not only reduces the motor operation load by minutely vibrating the motor 1 but also the shaft fitting backlash of the rotor magnet 21 and the transmission member 24 and the control object. This also acts to remove the looseness of engagement with the light quantity adjusting member 2 by minute vibration. Further, the frequency of the pulse output is preferably 15 KHz or higher because minute vibration noises cannot be heard if the frequency is higher than the audible range.

  According to the first embodiment described above, the pulse output having a cycle shorter than the time constant of the motor 1 is added to the drive control amount to obtain a drive signal, and the motor 1 is driven by the drive signal. The light quantity adjusting member 2 is operated according to the drive control amount while minutely vibrating according to the pulse output within a range that does not affect the drive control amount. Thus, the minute vibration of the motor 1 can reduce the load fluctuation at the time of control, can eliminate the fitting play generated in the mechanism, and can further reduce the minute vibration within a range that does not affect the drive control amount. Therefore, the light amount adjusting member 2 can be driven to the target value without impairing highly accurate and stable control. In particular, there is an effect of reducing the load fluctuation at the time of transition from the stop state to the operation state by minute vibration of the motor 1, and the light amount adjusting member 2 is smoothly moved to the target value (attenuated as it approaches the target value). Since the drive control amount is based on the control amount, it can be driven (because it operates slowly).

  The adder circuit 10 outputs a drive signal that reduces the minute vibration range of the motor 1 to a range that does not affect the drive control amount in accordance with the pulse output that attenuates the pulse output to a range that does not affect the light amount. Therefore, it is possible to perform high-precision operation control by appropriately setting the minute vibration range of the motor 1 to a range that does not affect the control amount.

  Further, since the vibration sound of the motor 1 to be minutely vibrated by the pulse output and the light amount adjusting member 2 which is a control target are set to be high sound of 15 KHz or higher, the noise due to the minute vibration of the motor 1 is higher than the human audible range. It is possible to hear the noise of minute vibrations without causing discomfort to the user.

  In addition, since the control object is the light amount adjusting member 2 that requires fine and smooth control, it is possible to provide a motor control device for adjusting the light amount that is optimal for drive control.

  FIG. 3 is a block diagram showing a configuration of a light amount adjusting device including a motor control device according to the second embodiment of the present invention. In the figure, 11 is a motor that drives a light amount adjusting member 12 described later based on a drive signal, 12 is a light amount adjusting member that is a controlled object that is driven by the motor 11 and adjusts the light amount, and 13 is a switch or knob. A light amount setting device that sets a target value of a predetermined light amount by operation, 14 is a drive control amount calculation circuit that calculates a drive control amount from the target value from the light amount setting device 13, and 15 is a cycle shorter than the time constant of the motor 11. A pulse output generating circuit 16 generates a pulse for minutely vibrating the motor 11, and 16 is an adding circuit that outputs the drive signal for driving the motor 11 by adding the pulse output and the drive control amount.

  In the above configuration, when a target value that is a predetermined light amount is set by the light amount setting device 13 by an external operation of a switch or the like, a drive control amount for driving the motor 11 to the target value is generated by the drive control amount calculation circuit 14. Calculated. A pulse for generating minute vibrations of the motor 11 is output from the pulse output generation circuit 15 at a cycle shorter than the time constant of the motor 11, and this pulse output and the drive control amount are added by the adder circuit 16 to generate a drive signal. Is output as In other words, the adder circuit 16 attenuates the pulse output that slightly vibrates the motor 11 to a range that does not affect the amount of light, and adds this to a drive control amount that drives the target value that is a predetermined amount of light. 11 is output. The adding circuit 16 has an addition ratio which is the inverse ratio of the resistance values set by resistors similar to the resistors 26 and 27 in FIG. 2, and the pulse output is set to 5% or less of the drive control amount, for example, preferably 1 at the time of addition. Attenuate to about% range.

  As a result, the motor 11 operates the light amount adjusting member 12. At this time, the light amount adjusting member 12 is slightly vibrated according to the pulse output included in the drive signal to reduce the load fluctuation in the stopped state, and the drive signal. The light amount adjusting member 12 is driven to the target position and stopped so as to obtain a predetermined light amount in accordance with the drive control amount included in. In this way, the drive signal to which the pulse output is added is output constantly or before operation even when the motor 11 is stopped, causing the motor 11 to vibrate slightly to reduce the load on the motor operation.

  Since the frequency of the pulse output is not higher than the audible range, minute vibration noise cannot be heard. Therefore, it is desirable that the frequency of the pulse output be 15 KHz or higher as in the first embodiment.

  According to the second embodiment described above, the pulse output having a cycle shorter than the time constant of the motor 11 is added to the drive control amount and used as a drive signal, and the motor 11 is driven by the drive signal. No. 11 operates the light amount adjusting member according to the drive control amount while minutely vibrating according to the pulse output within a range not affecting the drive control amount. In this way, the motor 11 minutely vibrates, so that load fluctuations during control can be reduced, fitting backlash generated in the mechanism can be removed, and minute vibrations within a range that does not affect the drive control amount. Therefore, highly accurate and stable control can be performed. In particular, it is possible to provide a motor control device that has an effect of reducing the load fluctuation at the time of transition from the stopped state to the operating state by minute vibration of the motor 11 and is resistant to the load fluctuation during operation.

  Specifically, the adder circuit 16 outputs a drive signal that reduces the minute vibration range of the motor 11 to a range that does not affect the drive control amount in accordance with the attenuated pulse output. The minute vibration range of the motor 11 during operation can be appropriately set to a range that does not affect the drive control amount, and high-precision control can be performed.

  Further, similarly to the first embodiment, the vibration sound of the motor 1 that is minutely vibrated by the pulse output and the light amount adjusting member 12 that is a control target is set to be a high sound of 15 KHz or more. Can be made higher than the human audible range, and minute vibration noise can be heard without causing discomfort to the user. Furthermore, since the control object is the light amount adjusting member 12 that requires fine and smooth control, it is possible to provide a motor control device for light amount adjustment that is optimal for drive control.

  In each of the embodiments described above, a light amount adjustment member such as a diaphragm or a shutter is assumed as the control target, but the present invention is not limited to this, and other adjustment members may be used.

It is a block diagram which shows the structure of the light quantity adjustment apparatus which comprised the motor control apparatus concerning Example 1 of this invention. FIG. 2 is a circuit diagram showing details of a partial circuit shown in FIG. It is a block diagram which shows the structure of the light quantity adjustment apparatus provided with the motor control apparatus concerning Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Motor 2,12 Light quantity adjustment member which is a control object 3 Position detection circuit 4 Light quantity detection circuit 5 Position setting circuit 6 Position control amount calculation circuit 7 Speed detection circuit 8, 14 Drive control amount calculation circuit 9, 15 Pulse generation Circuit 10, 16 Adder circuit 13 Light quantity setting device

Claims (7)

Control amount setting means for setting a target value of the control amount of the control object driven by the motor;
Drive control amount calculating means for calculating a drive control amount from the output of the control amount setting means;
Pulse output generating means for generating pulses having a cycle shorter than the time constant of the motor;
Adding the drive control amount and the pulse output, generating a drive signal for controlling the operation of the control object by minutely vibrating the motor within a range that does not affect the control amount of the control object; A motor control device comprising: addition means for outputting the drive signal to the motor. Position detecting means for detecting position information of a controlled object driven by a motor;
Position setting means for setting a target value of the position information;
Position control amount calculating means for calculating a position control amount from the difference between the position information and the target value;
Speed detecting means for detecting speed information of the control object;
Drive control amount calculation means for calculating a drive control amount from the difference between the position control amount and the speed information;
Pulse output generating means for generating pulses having a cycle shorter than the time constant of the motor;
Adding the drive control amount and the pulse output, generating a drive signal for controlling the operation of the control object by minutely vibrating the motor within a range that does not affect the control amount of the control object; A motor control device comprising: addition means for outputting the drive signal to the motor.   3. The motor control device according to claim 1, wherein the adding unit attenuates the pulse output to slightly vibrate the motor within a range that does not affect a control amount of the control target.   The motor control device according to claim 2, wherein the drive control amount calculated from the difference between the position control amount and the speed information is attenuated as the position control amount approaches a target value.   5. The motor control device according to claim 1, wherein a frequency of the pulse output is 15 KHz or higher, which is higher than an audible range.   The motor control device according to claim 1, wherein the control object is a light amount adjusting member that adjusts a light amount. A light quantity adjusting device comprising the motor control device according to claim 1.

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