JPS6195401A - Drift correcting device of detector - Google Patents

Abstract

PURPOSE:To control a controlled system safely by adding the output of a detector to a drift value to form a control signal when an operation lever is not located on a neutral position, and when loacated on the neutral point, outputting a reference value to control an actuator. CONSTITUTION:An operation signal from the detector 2 for the operation lever 1 is amplified 3, A/D converted 4 and then inputted to an operation part 7 as a digital signal V. When the lever 1 is located on the neutral position, the detector 5 turns a contact 6 to the (a) side and outputs a neutral point signal. The operation part 7 reads a signal V, and when the neutral point signal is not outputted, reads out a drift value DELTAV from a storage part 9, calculates V+DELTAV and outputs the calculated value to a D/A converter 8. Consequently, the actuator 11 is controlled by the D/A converted value V0 of the calculated value of V+DELTA. When the neutral point signal is outputted, the operation part 7 reads the reference value Vphi at that time from the storage part 9 and outputs the reference value Vphi to the converter 8. Therefore, the actuator 11 is held at a position corresponding to the reference value Vphi. Then, the operation part 7 calculates DELTAV=Vphi-V to update the drift value DELTAV in the storage part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detector drift correction device in a control system in which a control lever is operated to select a control signal to operate an actuator to be operated.

[Prior art]

In the circuit that amplifies and adjusts the force applied to operating levers such as levers and pedals, and the output of the detector that detects the amount of operation thereof, the characteristics of the detectors and amplifiers change due to environmental changes and aging, and the characteristics of the levers, pedals, etc. There were cases in which the output of the detector that passed through the amplifier at the neutral point changed, causing a signal to flow even though the levers, pedals, etc. were in the neutral position, causing the machine to operate (7).

[Problems to be solved by this invention]

Therefore, there is a method of detecting the neutral point using a limit switch, etc., and interrupting the circuit from the detector to the actuator to prevent the machine to be operated at the neutral point. When the deviation becomes large, the signal enters in a stepped manner during the conduction that follows the interruption at the neutral position, causing the machine to be operated to suddenly operate, which is dangerous.

Therefore, the present invention improves the above-mentioned disadvantages when the neutral point of the conventional control system is deviated, so that even though the control lever is at the neutral point, a signal is output and the machine does not operate. It is an object of the present invention to provide a detector drift correction device that can prevent the detector from being put away and safely control a controlled object.

[Means for solving problems]

According to the detector drift correction device according to the present invention, the first detector detects the operation amount of the operating lever, the second detector detects the neutral point of the operating lever, the calculation unit, and the reference when the operating lever is neutral. A data holding unit is provided to store the value and the amount of drift of the detector, and when the operating lever is not at the neutral point, the calculation unit adds the output of the first detector and the amount of drift and uses it as a control signal, and when the operating lever is not at the neutral point. At some point, the reference value is output to the controlled object to keep the controlled object at the reference position (stop position), and the difference between the reference value and the output of the first detector is updated as a drift amount in the data holding unit. There is.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments. FIG. 1 shows a block diagram of an embodiment of the present invention. In this block diagram, an operating lever 1 is provided with a first detector 2 for detecting the amount of lever operation. The first detector 2 is, for example, a potentiometer whose sliding part is mechanically connected, and outputs an operation signal Vi corresponding to the operation position of the operation lever 1. An amplifier 3 is provided at the next stage of the first detector 2, and amplifies the input signal v1.■! As~1
Output to converter 4. A/D converter 4 converts signal vx into A/D converter 4.
The D-converted digital signal is output to the calculation section 7.

The operated lever IK is provided with a second detector 5 that detects the neutral state of the lever, and when the operating lever 1 reaches the neutral position, it closes the a contact 6 and sends a neutral point signal to the I part 7. Output.

Further, the calculation unit 7 is equipped with a storage unit 9 for holding data, and stores the drift amount ΔV of the first detector 2 and the reference value ■φ when the operating lever is in the neutral position. Here, as shown in FIG. 2(a), the operating amount of the operating lever 1 and the amplifier 3
The relationship of the output signal ■1 is that when the operating lever 1 is in the neutral position, Vf=
The explanation will be given assuming that it is adjusted to be O. Second
(in the figure) shows an example of output that includes drift ΔV due to environmental changes such as temperature and aging.

The relationship between the drift lΔV and the reference value Vφ when the operating lever is in the neutral state stored in the storage unit 9 is as follows: ΔV=Vφ
- Specified by ■.

A D/A converter 8, an amplifier 10, and an actuator 11 to be operated are connected to the output side of the calculation section 7, and the D/A converter 8 converts the digital signal from the calculation section 7 into an analog signal. The signal is output to the amplifier 10 and actuates the actuator 11.

Next, the operation of the blocks in FIG. 1 will be explained according to the flowchart in FIG. 4. First, the calculation unit 7 is connected to the A/D converter 4
Read the A/D conversion value V of Vi from. Therefore, when the signal from the second detector 5 that detects the neutral state of the operating lever is not output, the drift amount V is read from the storage section 9, and the calculation of V+ΔV is performed and the signal is sent to the D/A converter 8. Output. Therefore, the actuator 11 has a D/A of ■+ΔV.
It is controlled by the conversion value VOK.

Further, when the output signal from the second detector 5 is input to the calculation unit 7 and it is detected that the control lever 1 is located at the neutral point, the calculation unit 7 stores the reference value when the control lever is neutral from the storage unit 9. It reads Vφ and outputs it to the D/A converter 8. For this reason,
7. The cut unit 11 is held at a position corresponding to a reference value Vφ in neutral.

Furthermore, the calculation unit 7 performs the calculation ΔV=Vφ−■ to update the drift amount ΔV in the storage unit 9. Here, instead of storing ΔV in the storage unit 9, ■ at the neutral point is stored, and instead of ■+ΔV, V+Vφ− (■ at the neutral point) is D
A configuration in which the signal is output to the /A converter 8 is also possible.

Further, it is also possible to use the bridge shown in FIG. 5 as a means for detecting lever operation 2. In FIG. In this embodiment, the amplifier 3 in FIG. 1 is replaced with a differential amplifier, and the amplifier 7 includes relays, comparators, AND, NO
It consists of an R gate, an UP/DOWN counter, and a D/A converter.

The output Vi of the first detector 2 is input to a differential amplifier 17, and after the difference with a reference value, which will be described later, is amplified and adjusted, it is further amplified by the amplifier 10 to operate the actuator 11.

A second detector 5 for detecting the neutral point of the operating lever 1 is provided with a relay 12 operated by an a contact 6. Further, the b contact 12b of the relay 12 is interposed in the line between the differential amplifier 17 and the amplifier 10, and when the second detector 5 detects the neutral point and the relay 12 is activated, the b contact 12b
b opens and the operation of the actuator 11 is stopped.

Although the amplifier 10 is used in this embodiment, a configuration may also be adopted in which the actuator 11 is directly actuated by the output of the differential amplifier 17.

Further, the output of the differential amplifier 17 is sent to a set of comparators 13.

1 and is compared with the reference voltage Vfl + vL applied to each comparator 13, 13'. The output of this comparator 13,1 is an ANDNO gate and N
The signals are inputted in parallel to an OR gate 14 to perform logical operations, and the calculated values of the gates 14 and 15 are inputted to AND gates 16 and 16', respectively. This AND game)
The a contact 12a of the relay 12 is connected to 16 and 1G in parallel with the calculated values of 14 and 15, respectively. Therefore, only when the second detector 5 detects the neutral point of the operating lever 1, the a contact 12 & closes and
NOR gates 14 and 15 are provided at the next stage.
It is output to the P/DOWN counter 18.

The output signal from the UP/DOWN counter 18 is converted by the D/A converter 8 into an analog signal VwK representing the detector output when the operating lever is in the neutral position, and is output to the differential amplifier 17.

In addition, a clock signal is supplied to the UP/DOWN counter 18 and the D/A converter 8, and the UP (DOWN)
N) When the signal is H, it counts one for each clock signal. UP (DOWN) L, UP, and DOWN all hold the L level common level signal count value, and the latest count value is stored as D/DOWN.
Output to A converter 8.

In this case, the differential amplifier 17 calculates Vo = K (Vi - VN
), and the relative relationship of each input and output signal is shown in the off-line diagram.

Further, FIG. 8 shows the input/output relationship of the comparators 13 and 13', and the comparator 13 outputs H when the input Vo is V and below, and L when the input Vo is V and above. Similarly, comparator 1 outputs H when the input Vo is below ■, and L when it is above VL.
Output. Also, vt<o<VH, and the input/output relationship between the outputs of the comparators 13 and 13' and the UP/DOWN counter 18 is shown.

This UP/DOWN counter 18 is UP (DO
While the WN) signal is high, the count is UP (DOWN) by 1 for every pulse of the clock signal.

While both DOWN signals are L, the count number is held in the previous state and the count number at that point is always sent to the D/A converter 8. The converter 8 outputs an analog value V corresponding to the count number at that time,
is sent to the differential amplifier.

In addition, Fig. 9 shows the period from when the neutral signal is input from the second detector 5 until Vo is corrected and enters the allowable range using the time axis, and in this figure, time 0 is when the neutral signal is input. It's time. Here, the input Vi from the first detector 17 is constant, but each time the clock signal is manually input, the reference value VN when the lever is in the neutral position increases, and the output Vo becomes VO=K (
(1VN), so it decreases and becomes stable within the allowable range.

In the above configuration, when the second detector 5 does not detect neutrality, the relay 12 does not operate, and the first detector 2 output Vi
and the reference output from the D/A converter 8, the Vo
= K (Vi - VN) is output as an output.

At this time, the input of the UP/DOWN counter 18 is the a contact 1
Since 2a is open, it is configured to be kept at L level, and in this state, UP/DOWN counter 1
8 holds a count value, and the reference value V which was adjusted when the control lever 1 was in the neutral position last time is always outputted from the D/A converter 8 to the differential amplifier 17.

Here, when the second detector 5 detects the neutral state of the operating lever 1, the relay 12 is activated, the b contact 12b is opened, and the output to the actuator 11 is cut off.

If the input Vi and the reference value VN at this time are different, the differential amplifier 1
Vo'' K (vI VN) is generated as the output of 7, but if it is within the permissible range, that is, VL<Vo<Vg, the output of comparator 13 is output from H1 comparator 13' as shown in the OFF diagram.
The output of becomes L, AND gate 15, NOR gate 1
Both outputs of 4 become L, resulting in the state in the upper right corner of FIG.

In addition, when neutral, the output of the NOR gate 14 is counted U.
P is configured so that the output of the AND gate 15 is connected to the count DOWN, but since both are L, the output of the AND gate 15 is connected to the count DOWN.
The DOWN counter 18 is not activated and VN is not changed.

Also, in the case of o≧VH, the comparator 13
, IA outputs both become L, and at this time NOR gate 1
Since the output of 4 becomes H, the signal of tJP is input as shown in the upper left state of FIG.

Therefore, as shown in FIG. 9, the count is increased by one every clock, and the reference value VN increases step by step.

This operation is repeated until ■ becomes approximately equal to Vi, and V
According to the relationship 6=K (vi vN), Vo also decreases step by step and becomes stable when Vi<Vo<V++.

In the case of Vo≦vL, the drift is corrected by the opposite effect, and the output at the next operation becomes an output with the drift corrected.

In this embodiment, the relay 12 and the a contacts +2 a and b contacts 12b are used, but it is also possible to use a semiconductor switch instead.

〔Effect of the invention〕

According to the detector drift correction device according to the present invention, in a control system in which a control lever is operated to select a control signal and operate an actuator to be operated, a signal is output even though the control lever is at a neutral point. This prevents the machine from operating and enables safe control of the controlled object.

[Brief explanation of drawings]

Figure 1 is a block diagram showing an embodiment of the present invention, Figure 2 ←)
, (b) is a graph showing an example of drift output and correction output, and FIG. 3 is a block diagram showing another example of the configuration of the first detector.
Fig. 4 is a flowchart showing the operation of the block diagram in Fig. 1, Fig. 5 is a circuit diagram showing another embodiment, Fig. 6 is a graph of output voltage and operation amount, and the OFF diagram is a comparison of a pair. Figure 8 is a state diagram of the counter based on the comparator output.
FIG. 9 is a characteristic diagram showing a state in which vo is corrected. DESCRIPTION OF SYMBOLS 1... Operation lever, 2... First detector, 3... Amplifier, 4... A/D converter, 5...
...Second detector, 6...A contact, 7...
... Arithmetic unit, 8... D/A converter, 9...
...Storage unit, 10...Amplifier, 11...
...Actuator, 12...Relay, 1
2a...A contact, 12b...B contact, 13
, 13'...Comparator, 14...NOR
Gate, 15, 16, 1G...AND gate, 17...Differential amplifier, 18...U
P/D OWN counter. Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A control system that operates an operating lever to select a control signal and operate an actuator to be operated, comprising: a first detector that detects an operating amount of the operating lever and outputs an operating signal; a second detector that outputs a neutral point signal when the neutral point of the lever is detected; a data holding unit that stores and holds an operating signal reference value of the first detector when the operating lever is neutral and a drift amount; The outputs of the first detector and the second detector are input, and the output of the second detector is input.
When there is no output from the detector, the amount of drift is read from the data holding section and added to the operation signal from the first detector, and this added value is output as a control signal to the actuator, and the second detection When a neutral point signal from the detector is input, the reference value of the data holding section is read and output to the actuator, and the difference between the output from the first detector and the reference value at that time is recorded as the data. 1. A detector drift correction device comprising: a calculation section configured to update the drift amount of the holding section.