JPH0650729Y2 - Distance measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a distance measuring device used for measuring a distance between each traveling body and another traveling body in a transport system such as an unmanned vehicle. In particular, the present invention relates to a distance measuring device having a function of dividing measured distance data into a plurality of ranges and outputting the divided distance data.

[Prior Art] A conventional distance measuring device of this type uses distance data obtained by distance measurement, for example, as shown in FIG.
Compared with 1 and L2, the level of the range output is set to "HIGH" according to the magnitude relation. For example, if the set value L1 is 1.0 m, the range 1 becomes "HIGH" if the distance data A is smaller than 1.0 m, and the range 2 becomes "HIGH" if it is 1.0 m or more.

When such a range output is used for motion control of the traveling body, if the distance data A is affected by noise or the like and chatters, the control target may malfunction.

FIG. 8 shows how the distance data A fluctuates near 1.0 m due to chattering. To divide the distance data A into ranges 1 and 2 as shown in FIG. It is necessary to have a hysteresis characteristic.

That is, the range 1 is set to "LOW" when the distance data A goes up to 1.1 m, and "HIGH" when it goes down to 0.9 m. Range 2 is set to "HIGH" when the distance data A rises to 1.1 m, and "LOW" when it falls to 0.9 m.

Conventionally, it has been
A method using an analog comparator 2 as shown in FIG. 10 and a method using two digital comparators 3 and 4 as shown in FIG. 11 are adopted. The former is a method in which the distance data A is converted into an analog amount by the D / A converter 1 and then compared with a reference value by the analog comparator 2, while the latter gives the distance data A to the two digital comparators 3 and 4. In this method, different set values B and B + b are compared.

[Problems to be Solved by the Invention] However, in the function of dividing the distance data measured by the conventional distance measuring device into a plurality of ranges and outputting the data,
The former method is costly because the D / A converter 1 is required, and the latter method uses two digital comparators 3 and 4, resulting in a complicated circuit configuration and high cost. There is.

Therefore, an object of the present invention is to provide a function of dividing the distance data obtained by measurement into a plurality of ranges and outputting the distance data at a preset fixed distance by using a simple and low-cost circuit configuration. It is to provide a distance measuring device to be realized.

[Means for Solving the Problem] In the distance measuring device according to the present invention, the distance data (A) approaches the set value (B) from the smaller one than the set value (B) and exceeds the set value (B + 2). The range is switched, and when the distance data larger than the other (B + 2) approaches (B + 2) and passes (B + 2) and reaches the set value B, the range is switched, and there are multiple distance data with such hysteresis characteristics. A distance measuring device having a function of dividing the output into a range and outputting the range data, the distance data inputting means and the holding means, wherein the distance data inputting means is a first signal line representing distance data of (B + 1). Group and a second signal line group representing distance data equal to or greater than (B + 2), the holding output of the holding means, the output from the first signal line group, and the second signal. And a means for providing the holding means with an input signal to be held in response to the output from the line group.

[Operation] The distance measuring device according to the present invention is provided with a fixed distance setting unit, which is a standard for range output, on the input signal line of the distance data obtained by measurement, and the setting unit output is held by the latch circuit. At the same time, since the operation is performed by feeding back to the fixed distance setting unit, it is possible to perform range division output of distance data having hysteresis characteristics in consideration of chattering accompanying measurement of distance data near a preset fixed distance.

[Embodiment] FIG. 1 is a diagram showing a schematic configuration of a distance measuring apparatus according to an embodiment of the present invention. FIG. 2 is a truth table for explaining the operation of the distance measuring device shown in FIG. FIG. 3 is a diagram showing hysteresis characteristics targeted by the distance measuring device shown in FIG.

The configuration of the distance measuring device of the present invention will be described with reference to FIG. In the device, A is the distance data obtained by measurement, B is the set value for turning off the range classification output when the relationship (A ≦ B) with the distance data A is satisfied, and LOUT is the range classification signal of the device. S is a strobe which is a signal of the output timing of the signal LOUT, and A1 is the distance data A (A = B +
When the distance data A is (A)
It is a signal that holds when ≧ B + 2). The device also inputs the value immediately before the signal LOUT and the current value of the signal A1,
AND circuit 5 that outputs the logical product of both with signal M1, the value of signal M1 and the value of signal A2 are input, and the OR circuit 6 that outputs the logical sum of both with signal M2 and signal M2 are latched as D inputs. ,
The latch circuit 7 outputs the signal M latched in response to the timing of the strobe S as the range division signal LOUT. As can be seen from Fig. 1, the range classification output is "O
The setting of the set value of N "is simultaneously performed in the input signal line portion of the distance data A.

Hereinafter, the operation of the distance measuring device according to the embodiment of the present invention will be described with reference to FIGS.

Numbers indicating the hysteresis characteristics in FIG.
Corresponding to the numbers in the right end of the table of FIG. In the table of Fig. 2, "L" is the signal level "LOW".
"H" indicates the signal level "HIGH". In Fig. 3, the change to "ON" is the change to level "HIGH", "OFF".
Changes to the level "LOW". The operation will be described separately for the case where the measurement target is far from the device and the case where the measurement target is approaching the device.

First, the case where the measurement target is far from the device, that is, the states indicated by or are described.

In this state, the measurement target is located between the set value B and the device, that is, the relationship (A ≦ B) is established, so that the signals A1 and A2 are at the level “LOW” and the circuit 5 and the circuit 6 are connected. Is output to. The circuit 6 outputs the signal "M2" of level "LOW" to the latch circuit 7, and accordingly, the latch circuit 7 latches the signal M2 and outputs the signal in response to the timing of the strobe S immediately after.
It is output as LOUT.

In this state, the measurement target is far from (B + 1), that is, the relationship of (A = B + 1) is established, and therefore the signal A1 is input to the circuit 5 at the level "HIGH".
At this time, since the value immediately before the signal LOUT, that is, the value in the state of, is the level "LOW", the signal M1 in the circuit 5 is output to the circuit 6 at the level "LOW". In response, the circuit 6
Since both M1 and A2 are at level "LOW", the signal M2 is set at level "LOW" and output to the latch circuit 7. In response, the latch circuit 7 latches the signal M2 and outputs it as the signal LOUT in response to the timing of the strobe S immediately after it is latched.

In the state of, the measurement target is far from (B + 2). That is, since the relationship of (A ≧ B + 2) is established, the signal A1 is output to the circuit 5 at the level “LOW”, and the signal A2 is output.
Is output to the circuit 6 at the level "HIGH". At this time, the circuit 6 sets the signal M2 to the level "HIGH" because the input signal A2 is at the level "HIGH", and outputs it to the latch circuit 7. Accordingly, the latch circuit 7 latches the signal M2 and outputs it as the signal LOUT in response to the timing of the strobe S immediately after. Therefore, the signal LOUT changes instantaneously from the level “LOW” to the level “HIGH” in response to the timing of the strobe S, and the instantaneous change from “OFF” to “ON” in the hysteresis characteristic of FIG. Change can be realized.

In the state of, the measurement target is farther, (A>
Since the relationship of B + 2) is established, signal A2 and signal
M2 maintains level "HIGH", and signal LOUT also maintains level "HIGH"
Is output so as to maintain. Therefore, it is possible to maintain the "ON" state in the hysteresis characteristic of FIG.

As described above, when the measurement target is far, the range-divided output signal LOUT according to the measurement operation of the present apparatus can satisfy the target hysteresis characteristic shown in FIG.

Next, when the measurement target approaches the device, that is,
The states indicated by or will be described.

In the states of and, since the relationship of (A ≧ B + 2) is established, the signal A2 is output to the circuit 6 at the level “HIGH”, and accordingly, the circuit 6 sets the signal M2 at the level “HIGH” to the latch circuit 7 Output to. In response, the circuit 7 latches the signal M2 and outputs it as the signal LOUT according to the timing of the strobe S immediately after.

In this state, the measurement target is approaching (B + 1), that is, the relationship of (A = B + 1) is established, so that the signal A1 is input to the circuit 5 at the level "HIGH". At this time, since the value immediately before the signal LOUT, that is, the value in the state of, is the level "HIGH", the signals M1 and M2 are output at the level "HIGH", and accordingly the signal LOUT is also at the level "H".
IGH "is maintained. Therefore, the state of" ON "in the hysteresis characteristic of FIG. 3 can be maintained.

In this state, the measurement target is approaching B. That is, (A ≧ B + 2) and (A = B +
Since the relationship 1) is not established, the signals A1 and A2 are output to the circuits 5 and 6 at the level "LOW". Therefore,
The signal M2 is output to the latch circuit 7 at the level "LOW". In response, the circuit 7 latches the signal M2, and immediately after the strobe S
Since the signal LOUT is output in response to the timing of, the signal LOUT instantly changes from the level "HIGH" to the level "LOW" according to the timing of the strobe S. Therefore, as shown in FIG. 3, it is possible to realize an instantaneous change from "ON" to "OFF" in the setting value B which is the range division output "OFF" value.

In the state of, the measurement target gets closer (A <
Since the relationship of B) is established, signals A1 and A2, signals
M1 and M2 maintain the level “LOW” and, accordingly, the signal LOUT
Is also output so as to maintain the level “LOW”. Therefore, it is possible to maintain the "OFF" state in the hysteresis characteristic of FIG.

As described above, when the object to be measured approaches, the output signal LOUT in the range classification by the measurement operation of the present apparatus can satisfy the target hysteresis characteristic shown in FIG.

FIG. 4 is a diagram showing a specific circuit configuration of the distance measuring device shown in FIG.

FIG. 5 is a timing chart of the distance measuring device shown in FIG.

FIG. 6 shows the hysteresis characteristics targeted by the distance measuring device shown in FIG.

Next, the configuration of the distance measuring device shown in FIG. 4 will be described. The device shown in FIG. 4 is more specific than the device shown in FIG. 1 in that the distance data A and the set value B are composed of eight signal runs D ₀ to D ₇ which are BCD codes. In addition, an OR circuit 8 that outputs the signal A2 is provided,
A reset signal RT for resetting the latch circuit 7 is provided. Other configurations are the same as those in FIG.

The operation of the distance measuring device shown in FIG.
It will be described with reference to the drawings.

The measured distance data A is 2, as shown in FIG.
It is assumed that the latch circuit 7 changes the input signal of the strobe S to the output timing of the range division output signal LOUT. Further, as shown in FIG. 6, DT is one data cycle time in which the distance data A is input to this device.

This device sets the set value B at which the range classification output is "OFF" to "2", and the distance data A is "2" as shown in FIG.
When, the range classification output is “OFF” and the distance data A
When is “4”, it is configured to have the history characteristic that the range division output is “ON”. That is, the signal A1 is obtained by the input of the signal lines D ₀ and D ₁ , and the signal A2 is obtained by the input of the signal lines D ₂ to D ₇ .

First, at the time of distance measurement, a reset signal RT is sent from the outside to the latch circuit 7, and the latch circuit 7 resets the data latched in the circuit in response thereto.

Now, when the distance measurement is conducted with the distance data A becomes "2", the output signal A2 of the circuit 8 is level "LOW" signal from that only the signal line D ₁ is a level "HIGH" M1 Also becomes the level “LOW”, and the signal M2 and the signal LOUT are also output at the level “LOW”. Therefore, the distance data A is "2"
When, the range output can be realized "OFF".

Next, when the distance data A changes from "2" to "3", the signal lines D ₀ and D ₁ are at the level "HIGH", but the signal LOUT
Since the value immediately before is at the level "LOW", the circuit 5 outputs the signal M1 at the level "LOW". At this time, the signal A2 is also at the level "LOW". Therefore, the signal M2 and the signal LOUT are also at the level "LO".
It is output at "W". Therefore, even if the distance data changes from "2" to "3", the range classification output can be kept "OFF".

Further, when the distance data A becomes "4" to "3", the signal A1 is a level "LOW", OR circuit 8 and the signal line D ₂ becomes level "HIGH", the signal level A2 "HIGH"
Is output to the OR circuit 6. In response, the circuit 6 outputs the signal M2 as the level "HIGH" to the latch circuit 7. The latch circuit 7 latches the input level “HIGH” signal M2,
Immediately after the strobe S signal rises, the signal LO
It is output as UT. Therefore, when the distance data A changes from "3" to "4", the instantaneous change of the range division output from "OFF" to "ON" can be realized.

Conversely, the movement direction of the measurement target changes and the distance data A is "4".
When the signal changes from "3" to "3", the signal A1 is at the level "HIGH" and the value immediately before the signal LOUT is also at the level "HIGH". Therefore, the AND circuit 5 sets the signal M1 to the level "HIGH" and the OR circuit. 6
In response to this, the circuit 7 also outputs the signal LOUT at the level “HIGH”. Therefore, even when the distance data A changes from "4" to "3", the range division output can be kept "ON".

Next, when the distance data A changes from “3” to “2”, only the line D ₁ of all the signal lines D ₀ to D ₇ has the level “HIGH”, so the signals A2 and M1 have the level “LOW”. Is input to the OR circuit 6, and the circuit 6 outputs the signal M2 to the latch circuit 7 as the level "LOW". In response, the circuit 7 latches the signal M2, and at the same time when the signal of the strobe S immediately after rises,
Output as signal LOUT. Therefore, when the distance data A changes from "3" to "2", the instantaneous change of the range classification output from "ON" to "OFF" can be realized.

The present apparatus is provided with a set value setting section which is a standard for range classification output on the input signal line of the measured distance data A, and the output of this set section is held by the latch circuit 7 to set the set value. Since the operation is performed by feeding back to the section, a timing chart as shown in FIG. 5 can be obtained. Therefore, it is possible to give the range classification output signal LOUT a hysteresis characteristic as shown in FIG.

[Advantages of the Invention] The distance measuring device according to the present invention is provided with a set value setting unit, which is a standard for range classification output, in the input signal line of measured distance data, and the setting unit output is used as a latch circuit unit. Since it is held by and is fed back to the set value setting section to operate, range output having a hysteresis characteristic in consideration of chattering of the distance data A near the set value distance is possible. Further, since the present device does not require a comparator and an adder for discriminating the magnitude relationship between the set value and the distance data obtained by measurement, the circuit configuration is simple and the cost is low. Furthermore, by setting the setting value as the measurement range M1N, MAX of this device,
It is possible to output an alarm (range over, range under) for distance data and to prevent runaway of the controlled object.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a distance measuring device according to an embodiment of the present invention. FIG. 2 is a truth table for explaining the operation of the distance measuring device shown in FIG. FIG. 3 is a diagram showing hysteresis characteristics targeted by the distance measuring device shown in FIG. FIG. 4 is a diagram showing a specific circuit configuration of the distance measuring device shown in FIG. FIG. 5 is a timing chart of the distance measuring device shown in FIG. Sixth
The figure is a diagram showing the hysteresis characteristic targeted by the distance measuring device shown in FIG. FIG. 7 is an explanatory diagram showing the range division output in the distance measuring device. FIG. 8 is an explanatory view showing an enlarged variation state of the distance data. 9th
The figure is an explanatory diagram for explaining the hysteresis characteristic. FIG. 10 is a block diagram showing a first example of a conventional distance measuring device. FIG. 11 shows the second part of the conventional distance measuring device.
It is a block diagram showing an example of. In the figure, 5 is an AND circuit, 6 and 8 are OR circuits, 7 is a latch circuit, A is distance data, B is a set value, S is a strobe, RT is a reset signal, A1, A2, M1, M2 and LOUT are each part. Is an output signal from. In each drawing, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. The distance data (A) approaches the set value (B) from the smaller value than the set value (B) and exceeds the set value (B + 2), the range is switched, and the range is larger than the other (B + 2). The range is switched when the distance data approaches (B + 2) and reaches (B + 2) and reaches the set value B. Distance measurement having such a hysteresis characteristic and having a function of dividing and outputting the distance data into a plurality of ranges. An apparatus comprising: distance data input means and holding means, wherein the distance data input means is equal to or larger than (B + 2) and a first signal line group representing distance data of (B + 1). A second signal line group representing distance data, the holding means being responsive to a holding output of the holding means, an output from the first signal line group, and an output from the second signal line group. hand And means for providing an input signal to be held, the distance measuring device.