JPH0587568A - Electronic level measuring device - Google Patents

Abstract

PURPOSE:To obtain the device capable of performing measurement with high accuracy even if it is dark. CONSTITUTION:A gray code pattern 2 showing a height position and a reference pattern 4 are formed to a staff 1 as light reflection patterns in the direction right angled to the length direction thereof. The light emitting part emitting light to a collimation position of the staff 1 and a linear image sensor on which the gray code pattern is formed are provided to an electron level (not shown in a drawing) and the height data calculated from the analogue signal corresponding to the gray code pattern 2 outputted from the linear image sensor is combined with the interpolation data calculated from the analogue signal corresponding to the min. bit pattern of a gray code and the reference pattern 4 to obtain a height value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electronic level device for electronically determining height.

[0002]

2. Description of the Related Art A conventional electronic level device forms a bar code on a linear image sensor by using a bar code having a bar code as a height display code and natural reflected light from the bar. And an electronic level for reading the height from the output of the image sensor.

[0003]

In the above-mentioned device, since the bar code is not constant in width, the circuit and calculation are complicated to further decompose the minimum bit to obtain the interpolated value. Further, since the natural reflected light is used, the signal / noise ratio deteriorates as the distance increases, and the measurement cannot be performed if it becomes a little dark. The present invention has as its object to solve such problems of the conventional device.

[0004]

An electronic level device according to claim 1, wherein a staff having a height display code is formed, and the height display code of the staff is imaged on a linear image sensor,
In the electronic level device comprising an electronic level for reading the height from the output of the image sensor, a gray code pattern showing a height scale in a direction perpendicular to the length direction is formed as a light reflection pattern on the staff, and the electronic level The level is provided with a light emitting unit that emits light to a collimated position of the staff.

An electronic level device according to a second aspect is the electronic level device according to the first aspect, wherein the staff has a gray code pattern and a reference pattern serving as a reference for a minimum bit of the gray code. And a signal conversion circuit for converting the analog signal corresponding to the gray code pattern output from the linear image sensor and the analog signal corresponding to the minimum bit pattern and reference pattern of the gray code into a digital signal. Comprising: height data obtained from the gray code digital signal and interpolation data obtained from the minimum bit pattern digital signal and the reference pattern digital signal, and a calculation processing means for calculating a height value. And

An electronic level device according to a third aspect is the electronic level device according to the first aspect, wherein the staff is a gray code pattern, an analog pattern for interpolation, and a reference for the analog pattern for interpolation. And a reference pattern to be formed as a light reflecting surface, the electronic level is an analog signal corresponding to the gray code pattern output from the linear image sensor and an analog signal corresponding to the interpolation analog pattern and the reference pattern are digital signals. A height value is calculated by combining a signal conversion circuit for converting into a digital signal, height data obtained from the gray code digital signal, and interpolation data obtained from digital signals corresponding to the interpolation analog pattern and the reference pattern. It is characterized by comprising an arithmetic processing means.

[0007]

In the electronic level device according to the first aspect, the light emitted from the electronic level is reflected by the gray code pattern at the collimation position of the staff and forms an image on the electronic level linear image sensor. A gray code serial electric signal is output from the output of the linear image sensor, and height position data is obtained from this signal. In the electronic level device according to claim 2,
The minimum bit pattern of the gray code output from the linear image sensor and the analog signal corresponding to the reference pattern that is the reference for the minimum bit are converted into digital signals, and the height data obtained from the gray code digital signals and the minimum bit digital The height value is calculated by combining the signal and the interpolated data obtained from the reference pattern digital signal. In the electronic level device according to claim 3, an analog signal corresponding to the gray code pattern, the interpolation analog pattern, and the reference pattern output from the linear image sensor is converted into a digital signal,
The height value is calculated by combining the height data obtained from the gray code digital signal and the interpolation data obtained from the interpolation digital signal and the reference pattern digital signal.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a staff according to an embodiment of the present invention. A gray code pattern 2 representing a height position is formed on the surface of the staff 1 by attaching a reflective tape in a direction perpendicular to the length direction of the staff 1 or by drawing with a reflective paint. A start pattern 3 having a different width from the gray code pattern 2 is provided on one side of the pattern 2.
On the other side, a reference pattern 4 having the same width as the gray code pattern 2 is provided.
It is formed by sticking a reflective tape or drawing with a reflective paint in the same manner as in.

FIG. 2 shows an electronic level block diagram of one embodiment of the present invention. In the figure, reference numeral 5 denotes a light emitting unit, which is composed of a light emitting element 6 and a light emitting drive circuit 7, and is controlled by a CPU 8 as an arithmetic processing unit to obtain a sum of a storage time of a linear image sensor and a round trip time of light described later. It emits light for a corresponding period of time, and this light is emitted toward the collimated position of the staff 1 via the cylindrical lens 9, prism 10 and objective lens 11. The light reflected by the start pattern 3, the gray code pattern 2, and the reference pattern 4 at the collimation position of the staff 1 is again input to the linear image sensor 13 from the hocus lens 12 via the objective lens 11 and the prism 10, and the hocus lens 12
Is adjusted so that the pattern is imaged on the linear image sensor 13. The reference pattern 4 is for obtaining a reference light amount when the minimum bit pattern is further decomposed (analog interpolation), and the start pattern 3 is necessary when discriminating the gray code and cooperates with the reference pattern 4. It is used when calculating the distance to the staff (described later).

In the linear image sensor 13, a gray code optical code signal indicating a height position is converted into a serial electric code signal, and this signal is amplified by an amplifier circuit 14 and input to a signal conversion circuit 15. In the signal conversion circuit 15, when the start signal according to the start pattern 3 is input, the gray code analog signal of the serial electric code signal is converted into the gray code digital signal by the comparator or the A / D converter and is input to the CPU 8.
With this gray code digital signal, it is possible to detect a height position up to, for example, a cm unit. In the signal conversion circuit 15, the analog signal output from the linear image sensor 13 is proportional to the image area of the minimum bit of the gray code (in FIG. 3, 16 is the minimum bit of the gray code, 17 is the linear image sensor 13). The minimum analog image area) and the reference analog signal corresponding to the area of the reference pattern 4 are converted into digital signals by the A / D converter and input to the CPU 8. CPU8
Then, the minimum bit is further decomposed (analog interpolation) by the ratio of the minimum bit digital signal to the reference digital signal to detect, for example, mm unit, and this is combined with the gray code digital signal to obtain highly accurate height position data. obtain. This data is displayed on the display 18 and is output to the outside and recorded in, for example, a recorder. In FIG. 2, reference numeral 19 is an image sensor drive circuit operated by the CPU 8.

4, 5 and 6 show modifications of the staff 1 in which analog patterns 20 ₁ , 20 ₂ and 20 ₃ are added to the staff 1. When the staff 1 is arranged at a short distance from the electronic level, the gray code pattern of the staff 1 is largely imaged on the linear image sensor 13 as shown in FIG. The output is 0 regardless of the interval L, and the minimum bit 16 cannot be decomposed in the height direction. Therefore, in order to resolve this interval, analog pattern 2
Patterns such as 0 ₁ , 20 ₂ and 20 ₃ are provided. If this pattern is provided, the areas in the height direction of this pattern are different, so that the difference in the amount of light incident on the linear image sensor 13 can be recognized and resolved. The analog pattern 20 _{1 in} FIG. 4 is formed in a diamond shape, the analog pattern 20 ₂ in FIG. 5 is formed in a triangular shape, and the analog pattern 20 ₃ in FIG. Even when this staff 1 is used, the analog pattern 20 is used with the electronic level shown in FIG.
_The space is decomposed according to the area of ₁ , 20 ₂ and 20 ₃ and combined with the gray code digital signal to obtain a highly accurate height.

When the staff 1 is arranged at a long distance from the electronic level, the gray code pattern 2 of the staff 1 forms a small image on the linear image sensor 13 as shown in FIG. The interval becomes narrower and the linear image sensor 13 cannot resolve the interval. Therefore, as described above, the minimum unit of height is obtained from the minimum bit pattern.

To increase the height accuracy, the number of gray codes is increased to narrow the bit interval of the gray code pattern. When the scale scale is, for example, 2 m, the resolution is 50 cm when the gray code is 2, and the minimum bit interval is 2 mm when the scale is 10, for example.

However, if the bit interval of the gray code pattern is made too narrow, when the staff 1 is at a long distance from the electronic level, the gray code pattern 2 of the staff 1 is small and imaged on the linear image sensor 13. So problems arise.

Generally, in a staff used at a distance of 1 to 100 m, the minimum bit pattern has a bit interval of 1 cm.
However, if the distance between bits is read using an analog pattern at a short distance, it is possible to read with high accuracy, and even at a long distance, the distance is 1 cm, so that it can be decomposed with high accuracy. At this time, the size of 1 bit of the trilinear image sensor is 14 × 1
The focal length of the objective lens is 4 μm and 150 mm. A small linear image sensor has been developed, and by using this and an analog pattern, the accuracy can be further improved. As described above, in order to improve the accuracy, considering the distance between the staff 1 and the electronic level, the size of the linear image sensor, the focal length of the objective lens, the number of gray code patterns in consideration of the analog pattern, etc., Therefore, it is necessary to set the bit interval of the minimum bit pattern to an optimum size.

In each of the staffs 1 shown in the drawings, the width of the start pattern 3 is larger than the width of the reference pattern 4, but this is to prevent surveying when used upside down. The interval between the start signal and the reference signal in the serial electric signal by the start pattern 3 and the reference pattern 4 output from the linear image sensor 13 changes depending on the distance between the staff 1 and the electronic level. Therefore, in the CPU 8,
The distance between the staff 1 and the electronic level can be calculated from the interval between the start signal and the reference signal.

[0018]

According to the electronic level device of the first aspect, the light is emitted from the electronic level to the staff and the reflected light is used, so that the signal / noise ratio is improved and accurate measurement can be performed. Even in the dark, it has the effect of allowing measurement. According to the electronic level device of the second and third aspects, there is an effect that the measurement can be performed with higher accuracy than the conventional one.

[Brief description of drawings]

FIG. 1 is a front view of a staff according to an embodiment of the present invention.

FIG. 2 is an electronic level block diagram of the above embodiment.

FIG. 3 is an explanatory view of the operation of the above embodiment.

FIG. 4 is a front view of a staff according to another embodiment of the present invention.

FIG. 5 is a front view of a third example of the staff of the present invention.

FIG. 6 is a front view of a fourth example of the staff of the present invention.

FIG. 7 is an explanatory view of the operation of the above embodiment.

[Explanation of symbols]

1 Level 2 Gray code pattern 3 Start pattern 4 Reference pattern 5 Light emitting part 8 CPU 13 Linear image sensor

Claims (3)

[Claims] 1. An electronic level comprising a staff having a height display code and an electronic level for forming an image of the height display code of the staff on a linear image sensor and reading the height from the output of the image sensor. In the device, a gray code pattern showing a height scale in a direction perpendicular to the length direction is formed as a light reflection pattern on the staff, and the electronic level includes a light emitting unit that emits light to a collimation position of the staff. An electronic level device comprising: 2. A gray code pattern and a reference pattern serving as a reference for the minimum bit of the gray code are formed on the staff as a light reflecting surface, and the electronic level is a gray level output from the linear image sensor. A signal conversion circuit for converting an analog signal corresponding to a code pattern and an analog signal corresponding to a gray code minimum bit pattern and a reference pattern into a digital signal, height data obtained from the gray code digital signal, and a minimum bit pattern digital 2. The electronic level device according to claim 1, further comprising arithmetic processing means for calculating a height value by combining the signal and the interpolated data obtained from the reference pattern digital signal. 3. A gray code pattern, an analog pattern for interpolation, and a reference pattern serving as a reference for the analog pattern for interpolation are formed on the staff as light reflecting surfaces, and the electronic level is A signal conversion circuit for converting an analog signal corresponding to the gray code pattern output from the linear image sensor and an analog signal corresponding to the interpolation analog pattern and the reference pattern into a digital signal, and a height obtained from the gray code digital signal The electronic level according to claim 1, further comprising arithmetic processing means for calculating a height value by combining data and interpolation data obtained from a digital signal corresponding to the interpolation analog pattern and the reference pattern. apparatus.