JPH07103793A - Recorder - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a recorder that does not cause hunting or overshoot while ensuring responsiveness. [Configuration] A deviation is obtained by a position deviation calculation unit 10 based on the pen position data and the pen position command data from the pen position detection calculation unit 9, and the pen speed is calculated by a pen speed calculation unit 11 based on the previous and current pen position data. When the deviation is larger than the predetermined value, the drive / braking control unit 13 issues a high-speed constant speed command, and when the deviation becomes smaller than the predetermined value and the high-speed constant speed movement moves to the low-speed movement, the drive / braking is performed. The controller 13 outputs a command for giving the motor a reverse rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recorder for receiving various input signals and performing analog recording on recording paper according to the level of the input signals in a plant or the like.

[0002]

2. Description of the Related Art A recorder is a device that operates in response to an external input signal and records a measurement signal on a recording sheet in an analog manner. And, although there are various configurations conventionally, in any recorder, a recording pen, a holding base for holding the recording pen, and a servo mechanism for moving the holding base to a predetermined position of the recording sheet are provided. It is provided, and a specific configuration is shown, for example, as shown in FIGS.

The recorder shown in FIG. 7 has a motor 31 for moving a holder for the recording pen and a pen position detection circuit 32 for detecting the current position of the recording pen by a resistance brush method or the like.
And a servo amplifier 33 that receives the pen position data and the pen position command data from the pen position detection circuit 32 and drives the motor 31 so as to match them.
The recorder shown in FIG. 8 includes a motor 31, a pen position detection circuit 32, a CPU 34 which receives the pen position command data and the pen position data, and calculates control output data, and a CPU 34.
D / A that converts the control output data from the device into an analog signal
It is composed of a converter 35 and a motor driver 36 which drives the motor 31 in response to a signal from the D / A converter 35.

The recorder shown in FIG. 9 has a motor 31, a pen position detection circuit 32, a servo amplifier 33, and a CPU 34.
And a D / A converter 35 and a motor driver 36. However, the recorder of FIG. 7 is an analog control system, and there is a problem that sufficient control performance cannot be obtained particularly near the target value. On the other hand, FIGS.
In this recorder, since the D / A converter is used, in order to perform high-precision control using the CPU, it is inevitable that the D / A converter must be highly accurate, and the device becomes expensive. There is a problem that it will end up.

In order to solve the above-mentioned problems, the present applicant has already applied for a recorder having a drive / control means, a proportional control means, and an integral control means, and performing motor control with high accuracy. (Japanese Patent Application No. 4-31829).

[0006]

The recorder according to the above application has improved accuracy as compared with the conventional recorder, but basically, in proportional control, high speed (constant speed ) When the deviation from the movement becomes small and the speed shifts to a low speed (constant speed), the driving to the motor is interrupted and the speed is changed to the low speed after reaching a predetermined speed. There is a problem that a pen overshoots due to inertia of a gear reduction system, a pen drive system, or the like, causing hunting and overshoot in pen position control.

In order to prevent this, it is conceivable to reduce the speed at a stage where the deviation is relatively large. However, if this is done, there is a problem that the response is bad. The present invention has been made in view of the above problems, and an object of the present invention is to provide a recorder that ensures responsiveness and does not cause hunting or overshoot.

[0008]

The recorder according to the present invention receives an input signal from the outside and calculates a position command value of the recording pen according to this signal, and an actual value of the recording pen. , A deviation calculating means for receiving the outputs of the command value calculating means and the pen position detecting means, and calculating a deviation between both outputs, and a constant of several steps according to the magnitude of the deviation. A motor for driving a pen that moves at a high speed, a means for outputting a command for moving the pen at a constant speed, and a pen movement for calculating a pen movement speed according to a change in the pen position detected by the pen position detecting means. The speed calculation means outputs a constant speed movement command, a reverse rotation constant speed movement command, and a stop command according to the deviation and the rate of change of the pen movement speed, and when the deviation decreases from high speed movement to low speed movement, the motor Reverse rotation or A driving / braking means for outputting a command of stop, the proportional control means for performing control in accordance with the output of the deviation calculation means, despite the operation of the proportional control means,
When the recording pen does not move, the integral control means for moving the recording pen toward the command value based on the gradually increasing data.

In this recorder, in addition to the pen position detecting means, the pen moving speed calculating means is provided, and when the deviation becomes small and the speed shifts to a low speed, a reverse rotation braking command is given to the motor, so that hunting or overshooting occurs. The occurrence of shoots is avoided.

[0010]

The present invention will be described in more detail with reference to the following examples. FIG. 1 is a block diagram of a recorder according to an embodiment of the present invention, particularly focusing on a servo mechanism. This apparatus includes a CPU 1 that receives pen position command data and a feedback signal, an adder circuit 2 that converts a digital output (motor operation signal) of the CPU 1 into an analog signal, and a motor driver 3 that receives an output of the adder circuit 2.
A DC brushless motor 4 driven by the output of the motor driver 3, a pen drive mechanism 5 for moving a recording pen (not shown) according to the rotation of the motor 4, and a pen position for detecting the position of the recording pen. A feedback signal is supplied to the detection circuit 6 and the CPU 1 according to the position of the pen.
And / D converter 7.

Although only one recording pen circuit is shown here, an adder circuit 2, a motor driver 3, a motor 4 and a recording pen drive mechanism 5 are individually provided for n recording pens. I have it. Further, the pen position command data is data given from the main CPU 8 every 100 mS, for example, and is data for commanding a recording pen position calculated according to an input signal supplied to the recorder.

The CPU 1 is a so-called one-chip microcomputer, and the processing contents are shown in a functional block diagram as shown in FIG. That is, the CPU 1 receives the feedback signal and calculates the pen position by the pen position detection calculation unit 9
And a deviation calculator 10 for calculating a deviation between the calculated pen position data and the pen position command data from the main CPU 8.
The pen speed calculator 11 calculates the moving speed of the pen based on the previous pen position data and the current pen position data, the integral calculator 12, and the drive / braking controller 13. The drive / braking controller 13 includes a motor rotation speed command calculator 14 and a polarity determiner 15. As a servo control characteristic, the motor rotation speed command calculation unit 14 has a pen speed (motor rotation speed) -deviation curve shown in FIG. 3, which is set to an optimum value in advance. 3 in FIG. 3 is made as small as possible (about 10%), and the characteristics are such that pen overshoot hunting does not occur. The difference between this setting curve and the actual pen speed is the speed deviation. A two-dimensional table for determining the next pen speed in accordance with this speed deviation and the pen position deviation input from the position deviation calculation unit 10 is provided, whereby the rotation speed of the motor and the rotation direction (polarity) are provided. A bit signal is output. In the curve shown in FIG. 3, when the deviation is smaller than α and the area is above the curve and the distance from the curve is large, a command value for high speed and reverse rotation is issued so that the pen is braked suddenly. It has become.

FIG. 4 is a circuit diagram of the adder circuit 2, in which a switch S4 which operates in response to a U / D discrimination signal (bit 4) output from the polarity discriminator 15 and a motor rotation speed command are given. A switch S3 that operates according to the motor operation signal (bit 3 to bit 0) output from the calculation unit 14
To S0, resistors R3 to R0 connected to the switches S4 to S0 and having a resistance value ratio of 1: 2: 4: 8, and resistors R3 to R0.
It is composed of a differential amplifier 16 that adds the voltage supplied via 3 to R0 according to the resistance ratio, and a feedback resistor Rf. Then, the switch S4 determines U / D (up /
ON / OFF operation according to the data)
A voltage of + 15V or -15V is supplied to the switches S3 to S0. That is, the data of bit 4 output from the polarity determination unit 15 functions as a forward / reverse rotation command signal for the motor 4.

The pen driving mechanism 5 is composed of a reduction gear connected to the motor 4, a pulley, a reel, a pen holding mechanism, a pen holding mechanism moving guide, and a recording pen. The recording pen moves within a range of 0 mm to 100 mm by the pen driving mechanism 5. The pen position detection circuit 6 is a so-called non-contact potentiometer of the electromagnetic induction type or the like, and has the configuration of FIG. 5, for example. That is, the pen position detection circuit 6 is provided in the sense coil circuit 1 laid in front of the recording pen moving range.
7, an excitation coil 18 for generating a magnetic field at the pen tip of the recording pen, and an excitation circuit 19 for driving the excitation coil 18,
A circuit switch 20 for sequentially switching the connection with the sense coil, a signal amplifier circuit 21 for amplifying an electromagnetic induction signal from the sense coil, and an A / D converter for converting the output of the signal amplifier circuit 21 into a digital signal. 22 and a CPU 23 that controls the overall operation. Then, the circuit switch 20 and the A / D converter 22 operate based on a switching command from the CPU 23, an A / D start command, etc.
By inputting the output of the converter 22 into the CPU 23, the pen position can be accurately detected.

Next, the overall operation of the recorder of the above embodiment will be described. When pen position command data is input from the main CPU 8 to the servo CPU 1, the pen position command data is added to the position deviation calculation unit 10 of the servo CPU 1.
On the other hand, the pen position detection calculation unit 9 calculates the current position of the pen by a feedback signal input to the pen position detection calculation unit 9 of the servo CPU 1 via the A / D converter 7. This pen position data is added to the position deviation calculation unit 10, and the position deviation calculation unit 10 calculates the deviation at that time. This deviation is added to the drive / braking calculation unit 13, and when the deviation is larger than α shown in FIG. 3, the motor circuit speed command calculation unit 15 determines that bits 0 to 3 of the motor are operating at high speed (constant speed). The signal is output to the adder circuit 2, and a bit 4 signal for approaching the target position is added to the adder circuit 2 by the polarity determination unit 15 according to the polarity of the deviation. The adder circuit 2 converts the input signal of bits 0 to 3 into an analog signal, and inputs the signal to the motor driver 3 with the polarity according to the bit 4 signal indicating the polarity, and the motor driver 3 converts the input signal into the input signal. Accordingly, the motor 4 is rotationally driven at a constant speed, and the recording pen of the recording pen drive mechanism unit 5 is moved so as to approach the target position. In this state, the pen speed calculation unit 11 calculates the pen speed from the previous pen position and the current pen position, and inputs this to the drive / braking control unit 13. Until the deviation becomes smaller than α, high-speed constant speed movement at the motor rotation speed W continues. Eventually, when the deviation becomes smaller than α, the set rotational speed of FIG.
With respect to the deviation curve, the motor has a large motor rotation speed due to the inertia of the deceleration system and the like, and the pen speed calculated by the pen speed calculation unit 11 also becomes large. Therefore, a deviation occurs between the actual calculated pen speed and the pen speed of the set curve.
The drive / braking control unit 13 inputs the calculated speed deviation and pen position deviation into a two-dimensional table, reads the target pen speed, and outputs a bit signal of the rotation speed and the rotation direction (polarity) of the corresponding data. Is output to the adder circuit 2. In this state, that is, when the deviation is smaller than α, when the actual control point is far from the set curve and moves farther to the upper area, a signal that causes the motor to rotate in reverse at high speed (high speed reverse Outputs a rotation command). As a result, sudden braking is applied, and when the actual control point enters the area below the set curve, reverse rotation is stopped. When the deviation becomes small and the control point enters the upper area again, the reverse rotation command is output again. By repeating the reverse rotation command and the stop command in this manner, the actual motor rotation speed-deviation curve is controlled so as to approach the set curve.

Further, the pen position deviation value is the dead band width ± d / 2.
If the pen position deviation value is still the same as the previous value even in the proportional control state, that is, if the pen has not moved, the integral calculation unit 12 counts, and the same number of times When N occurs N times, the drive / braking control unit 13 outputs the speed one level higher and the polarity depending on whether the deviation is positive or negative. By this, despite the proportional control operation,
When the pen does not move, the pen movement works, and it is possible to effectively cope with the secular change of the drive system of the recording pen. When the deviation becomes smaller than d / 2, the motor stops.

FIG. 6 is a flow chart showing the above operation. When the processing operation is started, first, step ST
In (1) (hereinafter referred to as ST), a deviation between the pen position and the pen command is obtained, and the deviation is larger than α in FIG. 3 or smaller than −α, −α ≦ deviation ≦ α, or −α / 2 <deviation. It is determined whether <α / 2 (ST2). Initially, if the deviation is very large and −α> deviation or α <deviation,
It is moved at the maximum speed (constant speed) in the direction determined by the sign of the deviation (ST3).

When the deviation becomes −α or more and α or less at several processing timings, it is judged by comparison with the previous time whether the same deviation continues for n times or more (ST4), and the deviation changes. In this state, the pen speed is calculated from the previous and current pen positions (ST5), the speed set value is calculated from the curve in FIG. 3 (ST6), and the pen speed-speed set value is calculated.
The speed deviation is obtained (ST7). Then, the two-dimensional table is referred to from the deviation and the speed deviation to obtain the rotation direction and the rotation speed (ST8). Even if the deviation is -α or more and α or less, but the pen does not move, if the same deviation continues n or more times,
That is, the result of the integration calculation is YES in ST4,
In ST9, a speed command of a level one level higher than the previous time is issued.
Eventually, when the deviation is larger than -α / 2 and smaller than α / 2, the operation is stopped (ST10).

[0019]

According to the present invention, in addition to the pen position detecting means, the pen speed calculating means is provided, and when the deviation becomes small and the high speed movement is changed to the low speed movement, a braking command by reverse rotation of the motor is given. So without slowing down the response speed,
Still, it is possible to obtain a recorder without hunting and overshoot.

[Brief description of drawings]

FIG. 1 is a block diagram showing a part of a recorder according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration of a servo CPU that constitutes the recorder of the embodiment.

FIG. 3 is a diagram showing a motor rotation-deviation characteristic set in the servo CPU of the embodiment.

FIG. 4 is a circuit diagram of an adder circuit included in the recorder of the embodiment.

FIG. 5 is a circuit diagram of a pen position detection circuit that constitutes the recorder of the embodiment.

FIG. 6 is a flowchart for explaining the operation of the recorder of the embodiment.

FIG. 7 is a block diagram showing a conventional recorder.

FIG. 8 is a block diagram showing a conventional recorder.

FIG. 9 is a block diagram illustrating a conventional recorder.

[Explanation of symbols]

 9 Pen position detection calculation unit 10 Position deviation calculation unit 11 Pen speed calculation unit 13 Drive / braking control unit

Claims (1)

[Claims] 1. A command value calculating means for receiving an input signal from the outside and calculating a position command value of a recording pen according to the signal, a pen position detecting means for detecting an actual position of the recording pen, and the command. A deviation calculation means for receiving the outputs of the value calculation means and the pen position detection means to obtain a deviation between both outputs, a motor for driving the pen for performing a constant speed movement of several steps according to the magnitude of the deviation, A means for outputting a command for moving at a constant speed, a pen moving speed calculating means for calculating a pen moving speed according to a change in the pen position detected by the pen position detecting means, and a change in the deviation and the pen moving speed. Output constant speed movement command, reverse rotation constant speed movement command, stop command according to the rate,
When the deviation decreases from high speed movement to low speed movement, a drive / reverse rotation or stop command is output to the motor.
If the recording pen does not move in spite of the operation of the braking means, the proportional control means that controls according to the output of the deviation calculation means, and the operation of the proportional control means, the command value is increased based on the gradually increasing data. A recorder comprising: an integral control unit that moves a recording pen.