JP2834486B2 - Motor control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a motor control device that controls a motor having a transition period and a steady period.

[Prior Art] Conventionally, speed control in this type of device is performed by using a well-known phase locked loop (PLL).
P). In this case, the control for the transitional time such as when the motor starts, the direction of rotation is switched, and when the motor stops, and the control for the steady state after reaching the target rotational speed are PL
The internal constant (gain) of L control is switched. By doing so, the supply current to the motor during the transition period is limited to suppress overshoot, and a smooth transition to the steady state is realized.

[Problems to be Solved by the Invention] However, since the supply current to the motor is limited during the transition period, the time required for the transition period increases, and at the time of startup, the approach distance from the start to the image front end is set to be long. And there is a problem that the device becomes large. Further, there is another problem that the transient required time affects the cycle from one image exposure to the next image exposure.

The present invention has been made in view of the above points, and an object of the present invention is to improve control of a transition period.

[Means for Solving the Problems] In order to solve the above problems, the present invention relates to a relationship between a state quantity and a speed control amount among at least one of a rotation speed of a motor and a position of an object driven by the motor. , A rule storage means for storing associatively as a fuzzy rule,
By performing fuzzy inference using the fuzzy rule, calculating means for calculating a speed control amount, and controlling the motor based on the speed control amount calculated by the calculating means when the motor is in a transitional period. And a control unit for controlling the motor by a control method other than the fuzzy inference when the motor is in a stationary time.

The present invention also provides a rule storage means for storing a relationship between at least one state quantity and a speed control quantity among a rotation speed of a motor and a position of an object driven by the motor in association with a fuzzy rule, Calculating means for calculating a speed control amount by performing fuzzy inference using the fuzzy rule; first control means for controlling the motor based on the speed control amount calculated by the calculating means;
A second control unit that controls the speed of the motor by PLL control using a signal output from an encoder according to the rotation of the motor and a signal corresponding to the target speed; Control by the control means and the second
And a control switching unit for switching between the control by the control unit and the control unit.

Example An example of the present invention will be described below in detail with reference to the drawings.

<Example of Configuration> FIG. 2 is a simplified cross-sectional view of the copying apparatus of the present embodiment. Reference numeral 110 denotes a platen glass on which a document to be copied is placed; 112, an optical system having an illumination lamp for illuminating the document; 108, a home sensor for detecting that the optical system is at a reference position;
Is an image sensor for detecting that the optical system advances and is the leading edge of the document. Further, a detection signal from the image sensor is generated even when the optical system moves backward. 111 is a photosensitive drum.

FIG. 1 is a basic block diagram of the optical motor control unit of the copying apparatus according to the present embodiment. An optical motor 106 drives the optical system 112. The optical motor 106 drives forward (optical system forward) and reverse (optical system backward). Reference numeral 105 denotes a driver for the optical motor 106. Ten
Reference numeral 7 denotes an encoder connected to the optical motor 106, which outputs a signal synchronized with the rotation of the optical motor 106. 100 is a well-known PLL control unit, and when rotating the optical motor 106 at a desired speed, a reference frequency FS corresponding to the desired speed is used.
Is input so that the phase angle with the encoder signal FG from the optical motor 106 becomes a constant angle.
And outputs a pulse width modulation signal P1 serving as the speed control signal.

101 is an optical motor speed control based on fuzzy inference described later, an output of a reference frequency FS necessary for performing the optical motor speed control by a PLL, a forward / reverse control signal F / R and a drive stop control signal ON / OFF, reverse, Yes and the control of stopping a CPU for calculation and control for one of the switching control of the optical motor speed control performed by performing either fuzzy control by PLL control, counter d _c, a counter t _c, a timer T _s doing. 103 is C
ROM for storing a program to be controlled by the PU 101 and a fuzzy rule 103a and a membership function 103b to be described later.
It is. Reference numeral 102 denotes a RAM used as a work area when performing control and fuzzy inference. 104 is a speed control signal P1 output by PLL and a speed control signal P2 output by fuzzy inference
(Here, P1 and P2 are both pulse width modulation signals.) The switching switch is switched by the signal SW of the CPU 101 described above. Reference numeral 108 denotes the home sensor described above.
09 is an image sensor. The output signals (High / Low) are both input to the CPU 101.

<Operation Example> Next, an operation example of speed control by fuzzy inference of the optical motor of the present embodiment will be described. The description of this operation example is the first.
This is performed using FIGS.

The CPU 101 counts the number of pulses output from the encoder 107 of the optical motor for a certain period of time, thereby
The speed of 112 is calculated, and the difference between the calculated speed and the target speed is calculated as a speed deviation. The distance deviation between the optical system 112 and the target position is calculated by comparing the number of pulses required for movement between the reference position and the target position with the number of pulses input from the encoder after passing through the reference position.

 In order to perform the fuzzy inference this time, two state quantities, the speed deviation of the target speed from the current speed and the distance deviation of the target position from the current position, are used.

 Also, as a control amount for controlling the speed of the optical system, an optical motor speed control amount is used.

3A to 3C show a fuzzy set called a membership function of the above-mentioned state quantities and control quantities.

The speed deviation, the distance deviation, and the optical motor control amount are largely divided into several groups. For example, in the case of the speed deviation, 1) S _s ... The speed deviation is small.

2) M _s ... Speed deviation is medium.

3) a large L _s ... speed deviation.

In the case of a distance deviation, 1) S _d ... The distance deviation is small.

2) M _d ... Distance deviation is medium.

3) a large L _d ... distance deviation.

And The degree belonging to each set is represented by a value from 0 to 1. Fig. 3A shows the membership function of the speed deviation, Fig. 3B
The figure shows the membership function of the distance deviation, and FIG. 3C shows the membership function of the optical motor control amount.

Next, a method of calculating the control amount of the optical motor from the state amount between the speed deviation and the distance deviation will be described. For determining the optical motor control amount, for example, the following fuzzy rule is used.

(Rule 1) If, if the speed deviation = L _s and distance deviation = M _d, the optical motor control amount = M _c (Rule 2) If velocity deviation = M _s and distance deviation = if M _d, the optical motor control Amount = S _c Thus, the fuzzy rules are set as required. No.
4A and 4B show the fuzzy rule used in this embodiment.

FIG. 5 is an example of calculating the control amount of the optical motor by performing fuzzy inference using the above (rule 1) and (rule 2). For example, speed deviation = x, distance deviation =
Consider the case of y.

In (Rule 1), in the set of L _s at the degree of mu _x with respect to the input x by Menbashitsupu function of the speed deviation, the set of M _d at the degree of mu _y for the input y by Menbashitsupu function of distance deviation include. After that, the minimum value of μ _x and μ _y is obtained, and the value is defined as the degree to which the condition part of (rule 1) is satisfied. The value and the MIN (minimum value) between Menbashitsupu function M _c of the control amount of the optical motor Taking operation becomes trapezoid indicated by the shaded area in S. The same calculation is performed in (rule 2), and the shape shown by the shaded portion of T comes out.

Thereafter, the sum of the set of S and the set of T is calculated, and a new set of U indicated by the hatched portion is created. The center of gravity P of this set is set as the control amount of the optical motor obtained by the fuzzy inference. In the case of the speed deviation = L _s and distance deviation = S _d, in the case of the speed deviation = M _s and distance deviation = S _d is not shown.

As described above, for all the fuzzy rules shown in FIG. 4, the degree of belonging to the fuzzy set of the control quantity is calculated from the degree to which the state quantity belongs to the fuzzy set in accordance with each of the fuzzy rules by the method described above, and the degree of belonging to each rule is calculated. The sum of the sets is calculated, the most likely control amount is calculated by obtaining the center of gravity, and the center of gravity is set as the control amount of the optical motor. Then, the optical motor is controlled according to the set optical motor control amount. This control amount is the PW of the optical motor.
M output DUTY.

<At the time of starting the optical system> Next, the procedure of the fuzzy inference at the time of starting the optical motor will be described with reference to the flowcharts of FIGS.

The routine of FIG. 6 is executed each time the optical system moves a predetermined distance (d) due to an encoder interrupt. This encoder interrupt routine is used until the position of the optical system reaches the image destination. On the other hand, apart from this routine, an interrupt routine for time measurement is provided in step S20 in FIG.
Counts up-counter t _c in a predetermined time interval. Counter t _c is cleared to zero at step S13 in during routine Figure 6. Accordance connexion, the moving speed of the optical system at that time from the value of the counter d _c and t _c are obtained.

First counts up-optical system moving distance counter d _c at step S11. Step obtains a moving speed-S12 the value of the counter t _c, calculates a speed deviation. Counter t
_c is cleared to zero in step S13 after the processing in step S12 ends. Calculating the distance deviation from the value of the counter d _c at step S14.

Next, in steps S15 and S16, the degree to which the state quantity belongs to the fuzzy set for each of the moving distance and the moving speed is determined, and the degree to which the control quantity belongs to the fuzzy set based on the newly set fuzzy rule is determined from the values. Ask. After completing this work for consideration, the process proceeds from step S15 to S17 to calculate the sum of the sets belonging to each rule,
In step S18, the most likely control amount is calculated by obtaining the center of gravity, and in step S19, the center of gravity is set as PWM data for controlling the optical motor.

When the moving speed of the optical system reaches the set value, the speed control of the optical motor is switched to PLL.

<At the time of reversing the optical system> Next, the procedure of fuzzy inference when the rotation direction of the optical motor is reversed will be described with reference to the flowcharts of FIGS.

The routine of FIG. 6 is executed each time the optical system moves a predetermined distance (d) due to an encoder interrupt. This encoder interrupt routine is used until the speed reaches a certain set value after the moving direction of the optical system is reversed. On the other hand, the present routine is provided separately from the seventh view of a time measurement interrupt routine, and counts up-counter t _c in a predetermined time interval. Subsequent processing in each step is the same as that at the time of startup.

When the moving speed of the optical system reaches the set value, the speed control of the optical motor is switched to PLL.

<At the time of stopping the optical system> Next, the procedure of the fuzzy inference when the optical motor is stopped will be described with reference to the flowcharts of FIGS.

The routine of FIG. 6 is executed each time the optical system moves a predetermined distance (d) due to an encoder interrupt. This encoder interrupt routine is used from the time the optical system movement stop command is received until the moving speed of the optical system reaches zero. Until a command to stop the movement of the optical system is received, the movement of the optical system is controlled by a conventional method. On the other hand, the present routine is provided separately from the seventh view of a time measurement interrupt routine, and counts up-counter t _c in a predetermined time interval. The processing of each of the following steps is the same as that at the time of starting and reversing except that the fuzzy rule of FIG. 4B is used. After the stop, normal start-up or inversion is performed.

<Switching between fuzzy control and PLL control> Next, referring to the flowchart of FIG. 8, the speed control of the optical motor by the fuzzy speed control and the PLL speed control at the time of starting, reversing and stopping the optical motor. The switching will be described.

First, in step S31, a target frequency FS (1 KHz) corresponding to the target speed of the optical motor is output to the PLL. Step S32
Then, the speed control of the optical motor is switched to the fuzzy speed control. In step S33, the optical motor is rotated forward (forward)
Let it. In step S34, it is determined whether or not the optical system has arrived at the image destination. If not, step S3 is performed for each predetermined distance.
Wait for the destination to arrive while performing the fuzzy control in step 4.

In step S35, the speed control of the optical motor is switched to the PLL speed control. In step S36 to excisional timer T _s of the timing for reversing the optical motor. In the step S37, the timer T _s is to determine whether or not Taimuatsupu, if you Taimuatsupu proceed to step S38, If you do not have Taimuatsupu wait for Taimuatsupu at step S37. In step S38, a target frequency FS (3 KHz) corresponding to the target speed at the time of reversal of the optical motor is output to the PLL.

In step S39, the speed control of the optical motor is switched to the fuzzy speed control. In step S40, the optical motor is reversed (reverse). In step S41, it is determined whether or not the frequency output by the optical motor via the encoder is equal to the target frequency FS output in step S38. If they are equal, the process proceeds to step S42. If they are not equal, the process waits for the target frequency while performing fuzzy control for each predetermined distance.

In step S42, the speed control of the optical motor is switched to the PLL speed control. In step S43, it is determined whether the optical system has reached the image destination. If it has arrived, the process proceeds to step S44, and if it has not arrived, it waits for arrival at step S43.

In step S44, the speed control of the optical motor is switched to the fuzzy speed control. Fuzzy speed control is step S4
The operation is performed until the optical system stops at 5.

[Effects of the Invention] As described above, according to the first to fourth aspects of the present invention, when the motor is in a transitional period, the fuzzy inference is performed by using the fuzzy rule stored in the storage means. Since the speed control amount is calculated and the motor is controlled based on the calculated speed control amount, the control time required for the transition period can be reduced. If the motor is in a steady state,
Since the motor is controlled by a control method other than the fuzzy inference, it is not necessary to store the fuzzy rules for the steady-state period, and the storage means for storing the fuzzy rules can be saved. Thereby, costs can be reduced. That is, it is possible to provide a motor control device in which the control time required for the transition period can be reduced and the cost is reduced.

Further, according to the invention as set forth in claims 5 to 11, there are provided first control means for controlling the speed of the motor based on fuzzy inference, and second control means for controlling the speed of the motor by PLL control, Since the control by the first control means and the control by the second control means can be switched at a predetermined timing, a fuzzy control effective for suppressing overshoot and a PLL effective for maintaining a stable rotation speed are provided.
Control can be performed at appropriate times, and a motor control device that performs speed control appropriate for the rotation state of the motor can be provided.

[Brief description of the drawings]

FIG. 1 is a basic block diagram of the optical motor control unit of the copying machine of the present embodiment, FIG. 2 is a simplified sectional view of the copying machine of the present embodiment, and FIG. 3A shows an example of a membership function of a speed deviation. FIG. 3B is a diagram showing an example of a membership function of the distance deviation. FIG. 3C is a diagram showing an example of a membership function of the optical motor control amount. FIGS. FIG. 5 is a diagram showing an example of fuzzy inference according to the present embodiment. FIG. 6 is a flowchart showing the procedure of an encoder interrupt routine. FIG. 7 is a flowchart showing the procedure of a timer interrupt routine. 5 is a flowchart showing a procedure for switching between speed control and PLL speed control. In the figure, 100: PLL control unit, 101: CPU, 102: RAM, 10
3 ROM, 103a Fuzzy rule, 103b Membership function, 104 Switching switch, 105 Driver, 106
…… Motor, 107 …… Encoder, 108 …… Home sensor, 109 …… Image sensor, 110 …… Origin platen glass, 111…
... Photosensitive drum, 112... An optical system.

Continuation of the front page (56) References JP-A-3-89371 (JP, A) JP-A-63-153531 (JP, A) JP-A-3-87712 (JP, A) JP-A-3-87713 (JP) JP-A-3-87762 (JP, A) JP-A-3-87763 (JP, A) JP-A-3-87764 (JP, A) JP-A-3-87772 (JP, A) 3-89881 (JP, A) Patent 2710839 (JP, B2) Patent 2706150 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02P 5/00 G05D 3/00 G05B 13/02

Claims (11)

(57) [Claims] 1. A rule storage means for storing a relationship between at least one of a rotational speed of a motor and a position of an object driven by the motor and a speed control amount in association with a fuzzy rule; Calculating means for calculating a speed control amount by fuzzy inference using a rule, and controlling the motor based on the speed control amount calculated by the calculating means when the motor is in a transition period, A control means for controlling the motor by a control method other than the fuzzy inference when the motor is in a steady state. 2. The motor control device according to claim 1, wherein said motor drives an optical system for exposing and scanning a document. 3. The transition period includes changing the driving direction of the motor in order to reverse the moving direction of the optical system during a period from when the driving of the motor is started to when the optical system reaches the vicinity of the leading end of the document. 5. The motor according to claim 1, wherein the motor is controlled to stop at a target speed after the motor is turned over, or the motor is controlled to stop the optical system. 3. The motor control device according to 2. 4. The control means uses a signal output from an encoder in accordance with the rotation of the motor and a signal corresponding to a target speed when the motor is in a steady state.
3. The motor control device according to claim 2, wherein the speed of the motor is controlled by PLL control. 5. A rule storage means for storing a relation between at least one of a rotation speed of a motor and a position of an object driven by the motor and a speed control amount in association with a fuzzy rule; Calculating means for calculating a speed control amount by fuzzy inference using rules; first control means for controlling the motor based on the speed control amount calculated by the calculating means; A second control means for controlling the speed of the motor by PLL control using a signal output from the encoder and a signal corresponding to the target speed, and controlling the first control means at a predetermined timing. A motor control device comprising: control switching means for switching between control by the second control means. 6. The state control device according to claim 1, wherein the first control means detects at least one state quantity of a rotation speed of the motor and a position of an object driven by the motor; A function storage unit that stores a function in which a speed control amount is expressed by a fuzzy set; and an inference unit that infers a speed control amount of the motor using the fuzzy rule and the function. 6. The motor control device according to claim 5, wherein the speed of the motor is controlled based on the speed control amount inferred from the following. 7. The motor control device according to claim 5, wherein said motor drives an optical system for exposing and scanning a document. 8. The switching means switches from the control by the first control means to the control by the second control means when the optical system reaches near the leading end of the image after the driving of the motor is started. The motor control device according to claim 7, wherein: 9. The switching means switches from control by the second control means to control by the first control means when reversing the driving direction of the motor to reverse the moving direction of the optical system. The motor control device according to claim 7, wherein: 10. The switching means, when the motor reaches a target speed after reversing the driving direction of the motor,
8. The motor control device according to claim 7, wherein the control is switched from the control by the first control unit to the control by the second control unit. 11. The switching means switches from the control by the second control means to the control by the first control means when the speed control for stopping the driving of the motor is started. The motor speed device according to claim 7.