JPH05264257A - Measuring device - Google Patents

Abstract

PURPOSE:To simplify and expedite measuring work by providing a plurality of standard and general measuring points on a material to be measured, and correcting each measurement value by numerical conversion so that the positioning error calculated from the measurement value of the standard measuring point and a set standard value is 0. CONSTITUTION:A master data processing means A reserves and processes the data related to a work 1 to be measured such as a vehicle body. Measuring means 7, 7,... measure a plurality of standard and general measuring points set on the work 1 from respective determined positions. An error arithmetic means B calculates the positioning error of the work 1 on the basis of the measurement value of the standard measuring point and the design standard value of the standard measuring point read from the means A. A work assembling error arithmetic means C corrects the measurement value of each measuring point by numerical conversion so that the positioning error in the error arithmetic means B is 0. Thus, the positioning error is eliminated from the measurement value of each measuring point, and a precise work assembling error can be determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device.

[0002]

2. Description of the Related Art For example, in an automobile assembly line, members such as a door and a hood are sequentially assembled to the opening of a shell-shaped vehicle body. In this case, if the vehicle body is not formed with sufficient accuracy, For example, when a door or the like is attached to a vehicle body opening, the clearance dimension around it becomes uneven, or a step is generated between the vehicle body part and the door.
In some cases, it may not be a product.

Therefore, conventionally, before assembling parts such as doors, the dimensional accuracy at the opening of the vehicle body is checked, and when the dimensional accuracy is worse than a certain allowable value, the vehicle body is lined out at that time. Therefore, the subsequent assembling work of doors and the like is not performed.

[0004]

However, as a conventional general method in this case, as disclosed in, for example, Japanese Patent Laid-Open No. 62-216876, the size of the opening of the vehicle body is measured by a visual sensor. Since the dimensional accuracy is determined directly from the measured value, it is difficult to intuitively evaluate the vehicle body accuracy, and there is room for improvement in terms of easiness or certainty in evaluating the vehicle body accuracy. It was

Further, the visual sensor is provided on a measuring robot arranged on the side of the carrying device, while the vehicle body is carried while being positioned at a predetermined position with respect to a mounting table carried by the carrying device. Measurement is performed by the above visual sensor as it is. In this case, each visual sensor performs measurement at a preset measurement position with the mounting table. Therefore, in order to perform the measurement with high accuracy, the positioning of the vehicle body with respect to the mounting table is required to be as accurate as possible. However, the positioning between the vehicle body and the mounting table is not always accurate, and there are usually some errors.
Therefore, conventionally, the positioning error between the vehicle body and the mounting table was measured prior to the measurement, and the measured positioning error was reflected in the actual measurement value to correct it. In that case, there is a problem that the measurement work becomes complicated and the workability is poor.

Therefore, the present invention simplifies and speeds up the measurement work itself by intuitively and easily and accurately evaluating the accuracy of the work to be measured and canceling the positioning error of the work to be measured during measurement control. It was made as an attempt to provide a measuring device designed to achieve this.

[0007]

In the invention of claim 1, as a concrete means for solving such a problem in the present invention, as shown in FIG.
Master data processing means A for storing and processing the master data regarding the above, a plurality of reference measurement points and a plurality of normal measurement points set on the workpiece 1 to be measured, are measured from predetermined measurement positions, and the measured values are output. Measuring means 7,7, ...
Based on the measured value at the reference measuring point output from the measuring means 7, 7, ... And the design reference value at the reference measuring point read from the master data processing means A Positioning error calculating means B for calculating the positioning error of the workpiece to be measured, and the measured values at the respective measuring points are corrected by numerical conversion so that the positioning error of the workpiece to be measured 1 obtained by the positioning error calculating means B becomes zero. By doing so, a work assembling error calculating means C for obtaining a work assembling error at each measurement point is provided.

According to the second aspect of the invention, as shown in FIG. 1, in the measuring apparatus according to the first aspect, the corrected measured value at each measuring point output from the work assembling error calculating means C is displayed. It is characterized in that it is provided with a vector converting means D for converting and outputting the vector, and a display means E for displaying the vector signal outputted from the vector converting means D on a monitor.

[0009]

With each of the inventions of the present application, the following effects can be obtained by adopting such a configuration.

According to the first aspect of the invention, the measuring means 7, 7,
.. When sequentially measuring each reference measurement point and each normal measurement point of the work 1 to be measured, the actual measurement value at each reference measurement point and the design at each reference measurement point extracted from the master data processing means A The positioning error of the workpiece 1 to be measured is calculated based on the reference value. By correcting the actual measurement value at each normal measurement point by numerical conversion so that the obtained positioning error becomes zero, the positioning error is eliminated from the measurement value at each normal measurement point, and each normal measurement point An accurate work assembly error at a point will be required.

According to the second aspect of the invention, the work assembling error at each normal measurement point obtained as described above is vector-converted by the vector converting means D, and the display means E is displayed.
Is displayed on the monitor as a vector. Therefore, by visually observing the magnitude and direction of the vector at each normal measurement point on the monitor, it is possible to intuitively and accurately evaluate the accuracy at each normal measurement point.

[0012]

Therefore, according to the measuring device of the first aspect, the positioning error of the workpiece to be measured is eliminated by software in a series of measuring operations, and the measuring point itself of each normal measuring point is a true workpiece. Since it can be evaluated as an assembly error, it is not necessary to measure the positioning error of the workpiece to be measured prior to the measurement work at each measurement point and reflect this in the actual measurement value for evaluation as in the past. Therefore, the measurement work becomes simple and quick, and the workability is improved.

According to the measuring device of the second aspect,
The true assembly error at each normal measurement point is displayed as a vector on the monitor as it is, and the operator can intuitively evaluate the accuracy at each normal measurement point. Compared to the case where the accuracy is evaluated from the itself, the accuracy of the work to be measured can be evaluated easily and quickly.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The measuring device of the present invention will be described in detail below. FIG. 1 shows the entire system of the measuring device according to the embodiment of the present invention. In FIG. It is a shell-shaped car body. This car body 1
It is carried by the carrying means 2 at a predetermined speed, and when it reaches a predetermined position, it is provided on each of the four measuring robots 3 to 6, which are arranged on both sides of the carrying means 2 in the carrying direction. .. are measured by the measuring instruments 7, 7 ,. Specifically, each of the measuring robots 3 to 6 measures the vertical dimension of the vehicle body 1 at a predetermined measurement position from the measurement position to a predetermined measurement point while the vehicle body 1 is being transported. There is no problem if this measured value agrees with the reference set value determined by design, but if this measured value is significantly different, the assembly error is large and it is determined that the accuracy is poor.

In this case, if there is no error in the positioning of the vehicle body 1 with respect to the conveying means 2, it is not necessary to take special consideration, but it is actually impossible to eliminate the positioning error of the vehicle body 1 at all. This is possible, and therefore it is necessary to eliminate this positioning error from the measured value in order to ensure good assembly error determination accuracy. Therefore, the master data processing means A and the positioning error calculation means B, which will be described later, are required. The work assembling error calculating means C is provided.
Furthermore, even if the measured value of each code part is obtained with the positioning error removed, there is a problem in workability to judge the suitability of the assembly error from this numerical value itself. In the example, as will be described later, a vector converting means D and a display means E are provided, and further an instruction means F is provided for instructing to the site so that the suitability of the assembly error can be visually and intuitively evaluated. Is. Hereinafter, the actual measurement control by each of these means will be described in detail with reference to FIG.

The master data processing means A has data relating to the vehicle body 1 as the work to be measured, for example, measurement points required for each vehicle type and design reference values at each measurement point (that is, if there is no positioning error with respect to the above-mentioned conveying means 2). In the case of the above, it is the vertical dimension value from the predetermined measurement position to each measurement point, which is actually given by the coordinate value (design coordinate value)), the tolerance of the assembly accuracy judgment, the polarity of the measuring instrument 7, etc. It is stored and processed as needed. When the master data processing means A gives an instruction to measure the vehicle body of a predetermined vehicle type, the vehicle body is displayed as an image on the monitor (not shown) as master data as shown in FIG.

In this embodiment, a plurality of measuring points are set at important points of each part of the vehicle body as indicated by ● or ○ in FIG. Here, the four measurement points indicated by ● are the measurement points whose measured values serve as the reference for correcting the positioning error of the vehicle body 1 with respect to the conveyance means 2, whereas the normal measurement points indicated by ○ are the measurement points. The value is the measurement point that is actually used to evaluate the vehicle body accuracy. The positions of these measurement points are measured by the measuring instruments 7, 7 ,.

The positioning error calculation means B is a design reference value at each reference measurement point output from the master data processing means A and an actual reference measurement point output from each of the measuring instruments 7, 7 ,. Is used to calculate the positioning error of the vehicle body 1 with respect to the conveying means 2, and the work assembly error calculating means C numerically converts the positioning error obtained by the positioning error calculating means B into numerical values. It is to be excluded from the measured value at the normal measurement point, and the calculation contents of these positioning error calculation means B and work assembly error calculation means C are as follows.

For example, in terms of coordinates, the master body
A positioning error as shown in FIG. 5 actually occurs between the (that is, the design coordinate value) and the measured vehicle body, and in this case, the measured values in the in-plane direction of the respective normal measurement points are d ₁ , It is assumed that d ₂ , ... Further, similarly, the measurement value in the direction perpendicular to each reference measurement point is, for example, d ₀₁ , d ₀₂ , _...
-(Not shown).

In this case, the measured values d ₀₁ ,
d ₀₂ , ... Should be zero when there is no positioning error of the vehicle body 1. That is, the values themselves of the measured values d ₀₁ , d ₀₂ , ... At the respective reference measurement points are grasped as the positioning error of the vehicle body 1. Therefore, in order to eliminate this positioning error from the measurement values at the above-mentioned normal measurement points, coordinate conversion is performed so that the above-mentioned measurement values d ₀₁ , d ₀₂ , ... Are all zero. FIG. 6 shows a state in which this coordinate conversion is performed.

When the coordinate conversion is performed in this way, the correction values s ₁ , s ₂ , ... Corresponding to the positioning error are subtracted from the measured values d ₁ , d ₂ ,. The values are h ₁ , h ₂ , .... Measured values at each normal measurement point after this correction h ₁ , h ₂ ,
Is the true assembly error amount at each normal measurement point.

As described above, by correcting the measurement values at the respective normal measurement points by numerical conversion corresponding to the positioning error of the vehicle body 1, the positioning error is completely eliminated from the respective measurement values,
The corrected measurement values at each normal measurement point all indicate the true error amount. Therefore, the positioning error is measured separately from the measurement of each part of the vehicle body 1 as in the conventional case, and this is used as each of the above measurement values. Compared to the reflection method, the measurement work can be simplified.

On the other hand, the vector conversion means D vector-converts the true error amount of each normal measurement point obtained as described above, and uses this as the error amount of each normal measurement point as shown in FIG. It is what is displayed on the monitor. Therefore, the operator can intuitively evaluate the suitability of the accuracy of each part by visually observing the magnitude and direction of the vector of each point on the monitor image.

Further, in this case, apart from the vector display of the numerical conversion result, it is judged whether or not the measured value of each part is within a predetermined tolerance, and if the measured value deviates from the tolerance range, this is indicated by the instruction means F. I am instructing the work site.

The overall flow of the above measurement control is shown in FIG. That is, first, in step S1, the master data about the applicable vehicle type is read, and
In step 2, data of each measurement point of the vehicle body is input, and in step S3, a design reference value of each measurement point is calculated.
The control of steps S1 to S3 is performed by the master data processing means A.

Next, in step S4, each measurement point is measured to obtain each measurement value (d). This is performed by the measuring instruments 7, 7, ..

Further, in step S5, the positioning error (s) of the vehicle body 1 is calculated by numerical conversion based on the measurement value at the reference measurement point. This control is performed in the positioning error calculating means B.

Next, in step S6, the measured value is corrected from the measured value (d) and the positioning error (s) to obtain a corrected measured value (h). This control is performed by the work assembly error calculating means C.

Further, the corrected measured value (h) is vector-converted (step S7) and displayed on the monitor (step S8). Also, the measured value after the correction (h)
Is compared with the set value A (step S10), and if (h> A), an NG instruction is given because the assembly error is greater than or equal to the allowable value (step S11), and (h <A ), It is assumed that the assembling accuracy is good, and the line O of the vehicle body 1
An FF instruction is given (step S12). This completes the measurement work.

[Brief description of drawings]

FIG. 1 is a system diagram of a measuring device according to an embodiment of the present invention.

FIG. 2 is a control flow chart in the display device of FIG.

FIG. 3 is a monitor display image showing a position of a measurement point on a vehicle body as a work to be measured.

FIG. 4 is a monitor display image in which the measurement values at each measurement point are shown as a vector.

FIG. 5 is an explanatory diagram of a measuring method.

FIG. 6 is a diagram illustrating a method of calculating a positioning error and a true error.

[Explanation of symbols]

1 is a vehicle body, 2 is a conveyance means, 3 to 6 are measuring robots, 7
Is a measuring instrument.

Claims (2)

[Claims] 1. A master data processing means for storing and processing master data relating to a workpiece to be measured such as a vehicle body, a plurality of reference measuring points and a plurality of normal measuring points set on the workpiece to be measured from predetermined measuring positions, respectively. Measuring means for measuring and outputting the measured value, current measurement based on the measured value at the reference measuring point output from the measuring means and the design reference value at the reference measuring point read from the master data processing means Positioning error calculating means for calculating the positioning error of the workpiece to be measured under the state, and the measurement values of the respective measuring points are corrected by numerical conversion so that the positioning error of the workpiece to be measured, which is obtained by the positioning error calculating means, becomes zero And a work assembling error calculating means for obtaining a work assembling error at each measurement point by performing . 2. The vector conversion means according to claim 1, which converts and outputs the corrected measurement value at each measurement point outputted from the work assembling error calculation means, and the vector conversion means. A measuring device comprising a display means for displaying a vector signal on a monitor.