JP2942906B2 - Electronic level device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic level device for electronically determining a height.

[0002]

2. Description of the Related Art A conventional electronic level device forms a bar code on which a bar code is formed as a height display code, and forms a bar code of the staff on a linear image sensor using natural reflection light from the staff. And an electronic level for reading the height from the output of the image sensor.

[0003]

In the above-described apparatus, since the barcode is not fixed width, the circuit and calculation become complicated to further decompose the minimum bit and obtain the interpolated value. In addition, since natural reflection light is used, the signal / noise ratio deteriorates as the distance increases, and measurement cannot be performed if the distance becomes slightly dark. An object of the present invention is to solve such a problem of the conventional device.

[0004]

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

According to a second aspect of the present invention, in the electronic level device according to the first aspect, the staff includes a gray code pattern and a reference pattern serving as a reference for a minimum bit of the gray code on a light reflecting surface. A signal conversion circuit that converts an analog signal corresponding to a gray code pattern output from the linear mage sensor and an analog signal corresponding to a minimum bit pattern and a reference pattern of the gray code into a digital signal. And arithmetic processing means for calculating a height value by combining 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

According to a third aspect of the present invention, in the electronic level device according to the first aspect, the staff has a gray code pattern, an interpolation analog pattern, and a reference to the interpolation analog pattern. A reference pattern is formed as a light reflecting surface, and the electronic level is a digital signal obtained by converting an analog signal corresponding to a gray code pattern output from the linear image sensor and an analog signal corresponding to an interpolation analog pattern and a reference pattern into a digital signal. , A height value calculated by combining 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 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 linear level image sensor of the electronic level. 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,
An analog signal corresponding to the minimum bit pattern of the gray code output from the linear image sensor and a reference pattern serving as a reference for the minimum bit is converted into a digital signal, and height data obtained from the gray code digital signal and minimum bit digital The height value is calculated by combining the signal and the interpolation data obtained from the reference pattern digital signal. In the electronic level device according to claim 3, a gray code pattern output from the linear image sensor, an analog signal corresponding to the interpolation analog pattern and the reference pattern are converted into a digital signal,
The height value is calculated by combining the height data obtained from the gray code digital signal with the interpolation data obtained from the interpolation digital signal and the reference pattern digital signal.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 shows a staff staff according to an embodiment of the present invention. On the surface of the staff 1, a gray code pattern 2 representing a height position is formed by sticking a reflective tape or drawing with a reflective paint in a direction perpendicular to the length direction of the staff 1, and a gray code. A start pattern 3 having a width different from that of 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 in the same manner as described above, or by drawing with a reflective paint.

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 comprises a light-emitting element 6 and a light-emitting drive circuit 7, and is controlled by a CPU 8 as an arithmetic processing means to calculate the sum of the accumulation time of a linear image sensor described later and the round-trip time of light. The light is emitted for a corresponding time, and this light is emitted toward the collimating position of the staff 1 through the cylindrical lens 9, the prism 10, and the 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 focus lens 12 through the objective lens 11 and the prism 10,
Is adjusted so that the pattern forms an image 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 required when determining a gray code and cooperates with the reference pattern 4. This is used when calculating the distance to the staff (described later).

In the linear image sensor 13, a gray code optical code signal or the like 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 a start signal based on the start pattern 3 is input, the gray code analog signal of the serial electric code signal is converted into a gray code digital signal by a comparator or an A / D converter and input to the CPU 8.
With this gray code digital signal, for example, a height position up to a cm unit can be detected. In the signal conversion circuit 15, an analog signal proportional to the imaging area of the minimum bit of the gray code output from the linear image sensor 13 (in FIG. 3, 16 is the minimum bit of the gray code, 17 is Of the reference pattern 4 and the reference analog signal corresponding to the area of the reference pattern 4 are converted into digital signals by an A / D converter and input to the CPU 8. CPU8
Then, the minimum bit is further decomposed (analog interpolation) according to the ratio of the minimum bit digital signal to the reference digital signal, for example, a unit of mm is detected, 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 output to the outside, for example, recorded on a recorder. In FIG. 2, reference numeral 19 denotes an image sensor drive circuit operated by the CPU 8.

[0012] Figure 4, 5 and 6, both showing a variation of the analog pattern 20 _1, 20 _2, 20 ₃ staff 1 was 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 forms a large image on the linear image sensor 13 as shown in FIG. The output is 0 anywhere in the interval L, and the minimum bit 16 cannot be resolved in the height direction. Therefore, analog pattern 2
0 _1, 20 _2, provided 20 patterns such as _3. If this pattern is provided, the area of the pattern in the height direction is different, so that the difference in the amount of light incident on the linear image sensor 13 can be recognized and the pattern can be decomposed. Analog pattern 20 ₁ of Figure 4 is rhombic, analog pattern 20 ₂ is triangular in FIG. 5, the analog pattern 20 ₃ of 6 reflectance are formed in different patterns depending on the location. Even when this staff 1 is used, the analog pattern 20 is used with the electronic level shown in FIG.
_The interval is decomposed according to the area of ₁ , 20 ₂ , and 20 ₃ and combined with a gray code digital signal to obtain a high precision height.

When the staff 1 is located 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. Are narrowed, and the linear image sensor 13 cannot resolve the distance. Therefore, as described above, the minimum unit of height is obtained from the minimum bit pattern.

In order to increase the height accuracy, the number of gray codes is increased to narrow the intervals between bits of the gray code pattern. When the staff scale is 2 m, for example, if two gray codes are used, the resolution becomes 50 cm. For example, when 10 gray codes are used, the minimum bit interval becomes 2 mm.

However, if the interval between the bits of the gray code pattern is made too small, the gray code pattern 2 of the staff 1 is formed on the linear image sensor 13 in a small size when the staff 1 is far from the electronic level. So a problem arises.

In a staff which is generally used at a distance of 1 m to 100 m, the bit interval of the minimum bit pattern is 1 cm.
If the distance between bits is read using an analog pattern at a short distance, the data can be read with high accuracy. At this time, the size of one bit of the linear image sensor is 14 × 1.
4 μm, and the focal length of the objective lens is 150 mm. A small linear image sensor has been developed, and the use of this and an analog pattern can further improve the accuracy. As described above, in order to improve the accuracy, the number of gray code patterns is considered in consideration of the size of the linear image sensor, the focal length of the objective lens, the analog pattern, etc., while taking into account the distance between the staff 1 and the electronic level. Therefore, it is necessary to set the interval between the bits of the minimum bit pattern to an optimum size.

In the staff 1 shown in the drawings, the width of the start pattern 3 is larger than the width of the reference pattern 4 in order to prevent the measurement if the wrong height is used. The interval between the start signal and the reference signal in the serial electric signal based on 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 for 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, 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 if it is dark, it has the effect of being able to measure. 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 the drawings]

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

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

FIG. 3 is a diagram illustrating the operation of the above embodiment.

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

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

FIG. 6 is a front view of a staff member according to a fourth embodiment of the present invention;

FIG. 7 is a diagram illustrating the operation of the above embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Staff staff 2 Gray code pattern 3 Start pattern 4 Reference pattern 5 Light emitting part 8 CPU 13 Linear image sensor

Claims (3)

(57) [Claims] 1. An electronic level comprising: a staff having a height display code formed thereon; and an electronic level for forming a height display code of the staff on a linear image sensor and reading the height from an output of the image sensor. In the device, a gray code pattern indicating 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 collimating position of the staff. An electronic level device, comprising: 2. A gray code pattern and a reference pattern which is a reference for a 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 that converts an analog signal corresponding to a code pattern and an analog signal corresponding to a minimum bit pattern and a reference pattern of a gray code into a digital signal; height data obtained from the gray code digital signal; 2. The electronic level device according to claim 1, further comprising an arithmetic processing unit for calculating a height value by combining the signal and interpolation data obtained from the reference pattern digital signal. 3. A gray code pattern, an analog pattern for interpolation, and a reference pattern that is a reference to the analog pattern for interpolation are formed on the staff as a light reflecting surface, and the electronic level is: A signal conversion circuit that converts an analog signal corresponding to a gray code pattern output from the linear image sensor and an analog signal corresponding to an interpolation analog pattern and a reference pattern into a digital signal, and a height determined from the gray code digital signal. 2. The electronic level according to claim 1, further comprising an arithmetic processing means for calculating a height value by combining the data with interpolation data obtained from a digital signal corresponding to the interpolation analog pattern and the reference pattern. apparatus.