JPS63235817A - Analogue/digital converter circuit equipped with slip correction circuit - Google Patents

Abstract

PURPOSE:To output a signal showing the accurate position at the point of time when a power source is turned ON to perform restarting even when an object to be measured moves at the OFF-time of the power source, by adding a slip correction circuit constituted using a comparing circuit and a gate circuit. CONSTITUTION:A slip correction circuit 28 is constituted of a comparing circuit 26 and a gate circuit 27 and provided to an A/D converter circuit 20. A bit is 0 when the rotary shaft of a position detector 13 is stopped at an angle of rotation of 0-180 deg. at the OFF-time of a constant voltage power source 40 and is 1 when said rotary shaft is stopped between 180-360 deg.. Further, an object to be measured slips when the power source 40 is in an OFF-state and the angle of the rotary shaft of the detector 13 changes and, when it is judged that the value of the highest rank bit becomes 0 1 or 1 0 when the power source 40 is again closed, an error is generated in the value stored in a non-volatile memory 23 and the count value of a counter 22 moving up and down at each time when the rotary shaft exceeds 360 deg. or 0 deg.. At this time, the circuit 28 judges the slip state of the object to be measured to correct the output of the counter 22 and, therefore, the data at the point of time when the power source is again closed can be accurately outputted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an analog/digital conversion circuit (hereinafter referred to as r
It is abbreviated as "A/D conversion circuit". ),
More specifically, the power is turned off (power outage) to the A/D conversion circuit that converts the analog signal output detected by the position detector (for example, a synchro transmitter) into a digital signal for manual input to the system controller (programmable controller or computer). It relates to a device that has a function to correct errors that sometimes occur when the object to be measured slips.

[Conventional technology]

Position measurement and control systems are used to control various industrial machines such as conveyance and loading machines, press machines, construction machines, and steel machines, and to automate production lines.

A position measurement/control system usually has a detection section that has an absolute type detector that outputs an absolute value signal such as a synchronizer or resolver to detect the position of a controlled object, and a digital signal that converts the analog signal output detected by the detection section. an A/D conversion circuit (signal conversion section) that converts the detected output into a digital signal, a control/processing section (system controller) that inputs the detection output converted to a digital signal and outputs a control signal, and drives a controlled object using the control signal. The drive unit includes a drive unit having an actuator that performs the following actions.

By the way, in the case of a system that requires measurement, measurement, and control over a long span, for example, output and display data of 4 digits or more, conventionally, the detection unit is equipped with a coarse measurement unit [(coarse): for example, in m units]. For precision measurement [(precision): e.g. n unit 1 of 2
Generally, the signal converter was equipped with two position detectors and two A/D converters to convert the output of each detector into a digital signal, but recently, one A detection unit with a multi-rotation type position detector and one A/D
An absolute value conversion system has been developed that uses a signal conversion section with a converter and is easily configured, and does not require resetting when restarting even if a power outage (including power outage or instantaneous power outage) or accidental noise occurs. There is.

FIG. 3 shows the system configuration of the above-described absolute value conversion method, which is a prior art for which the inventors of the present application have separately filed a patent application. This configuration and operation will be simply explained below.

In FIG. 3, 10 is a detection section, 20 is an A/D conversion circuit (signal conversion section), and 30 is a system controller (control/conversion section).
40 is a power supply unit (constant voltage power supply device).

The detection unit 10 detects the amount of movement of the object to be measured (not shown) using an input shaft 1.
The rotation speed (angle) is detected by a position detector (synchro transmitter) 13 via a gear 12. The analog signal output from the position detector 13 is converted into a digital signal by an A/D converter 21 of an A/D conversion circuit 20. A/D converter 2
The output of 1 is the precise measurement signal (lower digit: for example, l representing the crane unit).

system controller 30 (bit data signal)
At the same time, it is sent to an up/down counter (hereinafter referred to as "counter") 22 for receiving a coarse measurement signal (upper digits: for example, a 6-bit data signal representing units of m). The counter 22 counts one pulse each time the position detector 13 rotates once, and sends the output to the test system controller 30 as a rough measurement signal.

The A/D conversion circuit 20 is non-volatile in case the counter 22 is powered off because it cannot retain the count value data at that time and returns to O. Memory 23. Data switching circuit 2
4. A timing circuit 25 is provided (, J) and is configured to be capable of absolute value conversion.

That is, the timing circuit 25 detects off and on of the AC input power source and generates timing signals Gl and G2 as shown in FIG. The count value data of the counter 22 at that time is stored in the non-volatile memory 23 via the data switching circuit 24, and when the AC input power source is turned on, the count value data is read out from the non-volatile memory by the command of the timing signal Gt and the counter 22 I am trying to set it to .

Note that the power supply unit 40 uses a constant voltage power supply device configured using, for example, a switching regulator, and even if the AC input (commercial power supply) is turned off, the DC power supply is maintained as shown in FIG.
Since the output maintains the voltage for about 200 ms, the count value data of the counter 22 is stored in the non-volatile memory 23 using a timing signal command from the timing circuit 25 during that time.

[Problem to be solved]

The absolute value conversion type position measurement/control system (prior art) shown in Figure 3 is an excellent system that has a simple configuration and can measure long spans with high precision (for example, in dragon units), but it has some problems. is left behind.

That is, the detection unit 10. If the A/D conversion circuit 20 stops operating due to a power outage, etc., and the object to be measured moves due to slip (or inertia), the data from the counter 22, which is the higher digit data, will be lost when the power is turned on again. The problem is that the actual value may be counted by +1 or -1. This is because the position detector 13 outputs an absolute value signal when the power is turned on again, so the A/D
The data in the lower digits obtained through the converter 21 accurately indicates the value at the time of restart, but the data in the upper digits shows the value at power off (non-volatile This is because the data stored in the memory 23 will be shown as is.

A case in which incorrect data is output in this way will be supplementarily explained with reference to FIG.

FIG. 2(a) shows the case where the object to be measured returns in the opposite direction due to slipping, and FIG. 2(b) shows the case when it advances in the forward direction.

In case (a), the rotation axis of the position detector has exceeded 2 rotations and reached 211O, a power outage occurs, and the upper digit data (4
This is the case when the object to be measured moves and the rotation axis of the detector returns to the 1800 position when the digit 2 is stored in the nonvolatile memory.

When the power is turned on again in this state, the A/D conversion circuit outputs an incorrect data signal of 2800 even though it is actually 1800.

Case 6 in (b) is a case where the rotation axis of the position detector has exceeded 1 rotation and reached 1930, for example, and when a power outage occurs, the object to be measured moves and the rotation axis of the detector advances to 2220. . At this time, the nonvolatile memory stores data 1 of the upper digit.
, the A/D conversion circuit outputs an incorrect data signal of 1220 when the power is turned on again.

That is, in the case of (a), the data in the upper digits is increased by +1 from the actual value, and in the case of (b), it is increased by -1.

The present invention was made to solve the above problems, and even if the object to be measured moves when the power is turned off, when the power is turned on and restarted, a data signal indicating the exact position at that point is output. A/D with slip correction circuit that can
The purpose is to provide a conversion circuit.

[Means for solving problems]

In order to achieve the above object, the A/D conversion circuit of the present invention has a slip correction circuit configured using a comparison circuit and a gate circuit added to the circuit shown in FIG. When the power is turned off, the counter data X at that time and the most significant bits Y and sm of the output signal of the A/D converter are stored in the nonvolatile memory according to the command of the timing signal G.

When the power is turned on again, the upper digit data X stored in the nonvolatile memory is set in the counter, and at the same time, the most significant bit Y□ of the lower digit data is set in the comparator circuit according to the command of the timing signal Gt. give.

The comparison circuit compares the top of the data output from YMsa and the A/D converter when the power is turned on again (data changed due to the object under test slipping when the power is turned off) and Soto Z□,
When the comparison result is Y□l<2□3 [in the case of Fig. 2 (a)]
outputs the subtraction pulse L(0), and YM311 > Z1
4! At the time of 3m [in the case of Fig. 2 (b)], the addition pulse H
Output (1).

This pulse signal is given to the counter via the gate circuit.

When the pulse L is applied, the counter changes the data X by -1 (
(count down), and when pulse H is given, data X is incremented by 1 (count up).

The counter data corrected in this way is sent to the system controller.

[Effect]

In the present invention, the slip correction circuit determines the slip state of the object to be measured when the power is turned off, and if correction is necessary, corrects the output data of the counter, so that when the power is turned on again, the slip state of the object to be measured is corrected. Data can be output.

The necessity of data correction is determined as follows.

If the lower digit data is handled by 10 bits, the most significant bit Y□ represents 500, and when the power is turned off, the rotation axis of the position detector rotates at a rotation angle of 0° to i.
Y when stopped between so° (data value 0 to 499) is 01180° to 360° (data value 50
When stopped between 0 and 999), Y is 1.

The object to be measured slips when the power is turned off, and the rotation axis angle of the position detector changes, and the value of the most significant bit becomes 0 when the power is turned on again.
→ If the comparator determines that the value has become 1 or 1-0, there will be an error between the value stored in the non-volatile memory and the count value of the counter, which increases or decreases each time it exceeds 360 degrees or 0 degrees. That means that. In this case, correction is required.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an A/D conversion circuit equipped with a slip correction circuit according to the present invention. In the drawings, the same reference numerals as those mentioned above indicate the same or equivalent parts, and the explanation will be omitted as appropriate.

A comparison circuit 26 and a gate circuit 27 constitute a slip correction circuit 28, which is newly added to the A/D conversion circuit 20. The configuration of other parts is the same as that explained in FIG. 3, and the operation is as described above.

Note that the gate circuit 27 can be configured using an OR circuit as shown in the figure.

〔effect〕

As described above, according to the present invention, even if the measured object slips within a range of ±250 when the power is turned off, the position can be accurately measured and correct control data can be obtained when the power is turned on again.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the slip correction circuit (=J) A/D conversion circuit of the present invention. FIG. (b) is the case when the movement is in the positive direction. Figure 3 is a block diagram of the prior art absolute value conversion method position measurement/control system, and Figure 4 is the relationship between power on/off and timing signals. 10... Detection unit, 13... Position detector, 20... A/D conversion circuit, 21... A/D converter, 22... Counter, 23 ...Nonvolatile memory, 24...Data switching circuit, 25...Timing circuit, 26...Comparison circuit, 27...Gate circuit, 28...Slip correction circuit, 30...System controller , 40...Power supply section. Idebetsu person Nippon Electric Joki Co., Ltd.

Claims (1)

[Claims] 1. An analog/digital converter that inputs a detected value analog signal output from a position detector, converts it into a digital signal, and outputs a signal of the lower digit; and a digital converter of the analog/digital converter. a counter that counts signals and generates and outputs a signal representing the upper digit; a nonvolatile memory that temporarily stores count value data X of the counter and most significant bit data Y_M_S_B of the output signal of the analog/digital converter; A data switching circuit that switches the data to be stored in the nonvolatile memory, and a timing signal G that detects on and off of the AC input power source at each time.
This is an analog/digital conversion circuit comprising a timing circuit that generates signals G_1 and G_2, and a slip correction circuit having a comparator circuit and a gate circuit. The count value data X of the counter and the most significant bit data Y_M_S_B of the output signal of the analog/digital converter are stored in the nonvolatile memory via the data switching circuit, and the nonvolatile memory is The data X stored in the memory is read out and set in the counter, and the stored data Y_M_
S_B is applied to the comparator circuit, and the comparator circuit receives data Y_B.
M_S_B and the most significant bit data Z_M_ of the signal output by the above analog/digital converter when the power is turned on.
S_B and a signal based on the comparison result is given to the counter via the gate circuit to correct the data X of the counter by +1 or -1. conversion circuit.