JP3658685B2 - Subject distance measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is suitable for, for example, an outer shape measuring device such as an alignment tester or a tire, and removes the influence of the uneven portion of the tire side wall with a simple configuration, so that an accurate distance measurement value can be rationally and promptly obtained. The present invention relates to a distance measuring apparatus for a subject that can be obtained at a low cost.
[0002]
[Prior art]
The applicant uses a plurality of ultrasonic sensors, irradiates ultrasonic waves emitted from the sensors to a predetermined position on the tire side surface under rotation, measures the distance between the sensor and the tire side surface, and calculates the toe and camber values. A wheel alignment tester designed to be operated has been developed, and this has already been proposed in Japanese Utility Model Publication No. 5-28484.
[0003]
However, this conventional wheel alignment tester, when there is an uneven part such as a logo mark on the side wall of the tire irradiated with ultrasonic waves, an error of the uneven part occurs, and the distance between the sensor and the tire side surface Changed, and there was a problem that an accurate alignment measurement value could not be obtained.
[0004]
In order to solve such problems, for example, Japanese Patent Publication No. 7-11333 discloses the removal of an optical displacement meter that scans a measurement site of a tire having an uneven portion and sampling data corresponding to the uneven portion. A signal correcting means for correcting, and a measuring means for measuring a predetermined shape based on the corrected signal, and converting the sampling data into the frequency domain by high-speed Fourier transform as the signal correcting means. With a function, a removal function that removes components above a preset frequency, and an inverse transform function that transforms from the frequency domain to the time domain by inverse fast Fourier transform, just set the removal frequency in advance, An external shape measuring device such as a tire is shown which removes uneven components with good reproducibility.
[0005]
However, since the measuring apparatus performs high-speed Fourier conversion and inverse high-speed Fourier conversion, it requires a considerable processing time and is expensive.
[0006]
[Problems to be solved by the invention]
The present invention solves such a problem, and is suitable for, for example, an outer shape measuring device such as an alignment tester or a tire, and removes the influence of the uneven portion of the tire side wall with a simple configuration, thereby accurately measuring the distance. An object of the present invention is to provide a distance measuring apparatus for a subject which can obtain a value reasonably and promptly and which can be manufactured at low cost.
[0007]
[Means for Solving the Problems]
For this reason, the invention of claim 1 can calculate the amount of change between each measurement data between the distance sensor and a plurality of positions of the subject and the measurement data at the measurement position immediately before the measurement data. Based on the predetermined range of the absolute value of the change amount, it is judged as normal measurement data within the predetermined range and abnormal measurement data outside the predetermined range, and the abnormal measurement data is immediately before The output value at the measurement position can be temporarily output as a correction value, and the correction value obtained by adding the change amount to the output value at the immediately previous measurement position can be temporarily output for the normal measurement data, and measurements de and the correction values - by calculating the difference between the data, the final output value to be output, in the distance measuring apparatus of the subject with a control device, before Kiho positive value and the measured de - data Depending on whether or not the difference between Selectively enabling the output as a force value, the correction value and the measurement de - when the difference between the motor is a predetermined value or more, said enabling output correction value as the final output value, measured de - normal motor Alternatively, after detecting an abnormality, all measurement data can be temporarily output as correction values, and the validity of the abnormality data is re-evaluated to ensure the rationality and reliability of the final output value. The determination of whether or not to use abnormal measurement data with the logo of the above is determined to improve the reliability of measurement, making it suitable for external shape measuring devices such as alignment testers and tires.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention applied to an alignment tester will be described below. In FIGS. 1 to 6, 1 and 2 can be rotated on the floor of an inspection line, vehicle inspection station, automobile maintenance plant, etc. in an automobile manufacturing factory. A pair of installed rollers, one of which is linked to a drive source such as a motor, so that the wheels 3 (tires) of the subject vehicle can rotate on the rollers 1 and 2. It is placed.
In the figure, reference numeral 4 denotes an uneven portion such as a logo formed at a predetermined position on the side wall of the wheel 3.
[0011]
A plurality of ultrasonic sensors 5 to 7 which are distance sensors are provided outside each wheel 3, and these sensors 5 to 7 are arranged at equiangular (90 °) positions on the same circumference. The ultrasonic sensors 5 and 7 are disposed on a horizontal plane, and the ultrasonic sensor 6 is disposed above them.
[0012]
For example, the ultrasonic sensors 5 to 7 emit ultrasonic waves at a rate of 100 times per second, and when the wheel 3 rotates, every time the wheel 3 rotates 1/100, in other words, the outer periphery of the wheel 3. each position 100 equal portions, bets - and camber information about, that is, to allow measuring the distance L ₁ ~L _3, and enables inputs the signal to the arithmetic unit of the control apparatus described later.
The distance L from the ultrasonic sensors 5 and 7 to the center position of the wheel 3 is calculated by a calculator based on the distance L ₁ and L ₂ signals, and is obtained as L = (L ₁ + L ₂ ) / 2. .
[0013]
That is, the ultrasonic sensors 5 to 7 measure the time from when the ultrasonic wave is emitted until the reflected wave is obtained, so that the distance L ₁ from the ultrasonic wave emission position to the predetermined position on the outer surface of the wheel 3. the ~L ₃ are to be measured.
The distance signal is inputted to the controller 9 via the A / D converter 8, the apparatus 9 microcomputer has an arithmetic function and the storage function - a built-in motor, control shown in FIG. 6 in the device 9 furo -Is stored.
[0014]
The control device 9 starts the control operation when each wheel 3 of the vehicle to be tested has moved to a predetermined measurement position, turns on the ultrasonic sensors 5 to 7, and applies the corresponding wheel 3 from each sensor 5 to 7. The ultrasonic wave is emitted toward the surface, the time until the reflected wave is obtained is measured, and the distances L _{1 to} L ₃ from the ultrasonic wave emission position to each position on the outer surface of the wheel ₃ are measured. Yes.
[0015]
The distance measurement data is input to the calculation unit of the control device 9 every moment, and the change amount of the measurement data is calculated by the calculation unit.
That is, at the respective continuous measurement positions P _{1 to} P ₇ in FIG. 4, the amounts of change Δ _{1 to} Δ ₇ that are differences between the measurement data before and after are calculated, and whether or not the absolute value is within a predetermined range. Determine whether.
[0016]
The specified value that defines the allowable limit of the change amount Δ is set corresponding to the substantially uneven displacement of the uneven portion 4, which is set equal to each measurement data, and the change amount Δ is In the case of deviating from the predetermined value, for example, in the case of P ₃ , P ₅ , and P _{6 in} FIG. Yes.
[0017]
On the other hand, when the amount of change Δ is within the predetermined value, for example, in the case of P ₂ , P ₄ , and P _{7 in} FIG. 4, the change amount Δ ₂ , A value obtained by adding Δ ₄ and Δ ₇ is temporarily output as a correction value.
[0018]
Next, the temporary output value, that is, the correction value is compared with each measurement data, and the difference δ _{1 to} δ ₇ is calculated to determine whether or not the absolute value is within a predetermined value.
The predetermined value is set to be approximately equal to the specified value at the time of the change amount determination, and when the difference between the temporary output value and each measurement data is within a predetermined value, for example, δ ₆ The data is output as the final output value.
[0019]
On the other hand, if the difference between the temporary output value, that is, the correction value and each measurement data deviates from a predetermined value, for example, δ ₃ and δ ₆ , the temporary output value is output as the final output value. I have to.
[0020]
Then, the control device 9 uses the toe and camber arithmetic expressions stored in the storage unit based on the final output values of the distances L _{1 to} L _{3 at} the measurement positions P _{1 to} P ₇ . The camber is calculated and output to a CRT or the like so that it can be displayed.
[0021]
In addition, reference numeral 10 in the figure denotes an air blowing pipe containing ultrasonic sensors 5 to 7, which communicates with an air chamber (both not shown) through an air conduit to suppress temperature changes in the ultrasonic propagation path. In addition, variations in the propagation speed of ultrasonic waves are prevented.
[0022]
In the above-described embodiment, the wheel 3 is rotated on the rollers _{1 and 2} and the distances L _{1 to} L ₃ are measured at the multipoint positions of the wheel 3, but the wheel 3 under the alignment adjustment is shaken. The distances L _{1 to} L ₃ are measured at multiple points in a certain range of the wheel 3 while being placed on a movable turn table and swinging or rotating the wheel 3 under the adjustment operation. May be.
[0023]
The object distance measuring apparatus configured as described above performs simple arithmetic processing such as a difference between each measurement data and a difference between each measurement data and an allowable value as will be described later. -Sophisticated arithmetic processing such as Fourier transform or inverse high-speed Fourier transform is not required, and the processing time can be increased and the control device 9 can be made inexpensive.
[0024]
Next, when measuring the alignment of the wheel 3 by the alignment tester, the wheel 3 of the vehicle to be tested is put on the rollers 1 and 2 and the rollers 1 and 2 are rotated to rotate the wheels 3. To do.
Then, the ultrasonic sensors 5 to 7 are turned ON, and ultrasonic waves are emitted from the ultrasonic sensors 5 to 7 toward the corresponding wheels 3. For example, ultrasonic waves are emitted at a rate of 100 times per second. In other words, every time the motor rotates 1/100, distances L _{1 to} L ₃ from the ultrasonic emission position to each position on the outer surface of the wheel ₃ are measured at each position obtained by equally dividing the outer periphery of the wheel 3 by 100. . At that time, air is blown out from each blowing pipe 10 to suppress the temperature change of the ultrasonic propagation path.
[0025]
The measurement signals of the distances L _{1 to} L ₃ are input as measurement data to the calculation unit of the control device 9 every moment, and the calculation data change amount Δ is calculated by the calculation unit.
That is, at each successive measurement position P _{1 to} P ₇ , change amounts Δ _{1 to} Δ ₇ , which are differences between successive measurement data, are calculated, and whether or not the absolute value is within a predetermined range. judge.
[0026]
In the case of P ₃ , P ₅ , P ₆ where the change amount Δ deviates from the predetermined value, the final output values at the previous measurement positions, that is, P ₂ , P ₄ , P ₅ are obtained. Temporarily output as a correction value. In such a case, for example, it is estimated that P ₃ , P ₅ , and P ₆ are the positions of the uneven portion 4.
By doing so, the measurement position to detects an abnormal variation Δ as shown in FIG. 5 (b), the said measuring de - Cancel the data, de by the abnormality detecting portion as shown in FIG. 5 (c) - The data is set to zero to prevent a decrease in the reliability of the alignment measurement value due to the abnormal data.
[0027]
On the other hand, when the amount of change Δ is within a predetermined value, for example, in the case of P ₂ , P ₄ , and P _{7 in} FIG. 4, the output values at the previous measurement position, that is, the immediately preceding P ₁ , P ₃ , and P ₆ . In addition, a value obtained by adding the change amounts Δ ₂ , Δ ₄ , Δ ₇ (Δ ₇ = 0) is temporarily output as a correction value.
In this case, since Δ ₇ is zero, the correction value of P ₇ is equivalent to the measurement data.
In this way, a normal change amount Δ is allowed, and this is used as normal data to maintain the reliability of the alignment measurement value.
[0028]
Next, the temporary output value, that is, the correction value is compared with each measurement data, and the difference δ _{1 to} δ ₇ is calculated to determine whether or not the absolute value is within a predetermined value.
The predetermined value is set to be equal to the predetermined value at the time of the change amount determination, and when the difference between the temporary output value and each measurement data is within a predetermined value, for example, P ₆ , the measurement data Output the final output value.
[0029]
On the other hand, when the difference between the temporary output value, that is, the correction value and each measurement data deviates from a predetermined value, for example, in the case of P ₃ and P ₆ , the correction value is output as a final output value. The abnormal data once canceled in this way is checked for the presence or absence of an abnormality with the output value at the immediately preceding position, thereby re-evaluating the validity of the abnormal data, confirming its authenticity, and checking the data. The reliability of alignment measurement values is maintained.
[0030]
Thus, for example, measuring de - data from gradually increasing or gradually decreasing as in FIG. 5 (a), the process proceeds to the normal tendency to repeat a minute increase or decrease, or the increasing or decreasing tendency of migrating to the opposite side tends inverted The dynamics of the measurement data is accurately and reasonably evaluated.
[0031]
When this point to correct each measured distance L ₁ ~L ₃ Based on the abnormal data of FIG. 5 (a) - irregularities corresponding to data locations, the final output data of FIG. 5 (d) - deleted from data In addition, the increasing / decreasing tendency of each measurement data can be confirmed. Therefore, the reliability of the alignment measurement value due to abnormal measurement data can be avoided, and alignment adjustment can be performed accurately.
[0032]
The control device 9 sets the distance L from the ultrasonic sensors 5 and 7 to the center position of the wheel 3 as L = (L ₁ + L ₂ ) / 2 in the calculator based on the distance L ₁ and L ₂ signals. Based on the calculated values and the final output values of the distances L _{1 to} L _{3 at} the measurement points P _{1 to} P ₇ , the to and the camber calculation formulas stored in the storage unit The camber is calculated and output to a CRT or the like for display.
[0033]
【The invention's effect】
As described above, a first aspect of the invention, the compensation values measured de - depending on whether the difference between the motor is equal to or greater than a predetermined value, the measurement de - selectively the data or correction value as a final output value enabling output, the correction value and the measurement de - when the difference between the motor is a predetermined value or more, because the output can be the correction value as a final output value, measured de - after detecting normal or abnormal in data All the measurement data can be temporarily output as correction values, and the validity and reliability of the final output value can be ensured by re-evaluating the validity of the abnormal data. Therefore, it is possible to improve the reliability of the measurement by determining whether or not the abnormal measurement data is used, and it is suitable for an outer shape measuring device such as an alignment tester or a tire.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the state of alignment measurement according to the present invention.
FIG. 2 is an explanatory view showing a state of measuring a toe according to the present invention.
FIG. 3 is an explanatory view showing a measurement situation of a camber according to the present invention.
FIG. 4 is an explanatory diagram showing a correction state of a distance signal according to the present invention.
FIG. 5 is a timing chart sequentially showing the processing status of distance signals according to the present invention.
FIG. 6 is a chart showing a control flow by the control device of the present invention.
[Explanation of symbols]
3 Subject (wheel)
5-7 Distance sensor
9 Controllers L _{1 to} L ₃ Distance signal

Claims (1)

The amount of change between each measurement data between the distance sensor and multiple positions of the subject and the measurement data at the immediately preceding measurement position can be calculated, and the absolute value of the amount of change is based on a predetermined range. In addition, normal measurement data within a predetermined range and abnormal measurement data outside the predetermined range are determined, and the output value at the immediately preceding measurement position is used as a correction value for the abnormal measurement data. Temporary output is possible, and for the normal measurement data, a correction value obtained by adding the amount of change to the output value at the immediately preceding measurement position can be provisionally output, and each correction value and measurement data difference by calculating the, the final output value to be output, in the distance measuring apparatus of the subject with a control device, before Kiho positive value and the measured de - difference between the data whether more than a predetermined value Accordingly, the measurement de - selectively enable output data or the correction value as a final output value And, the correction value and the measurement de - when the difference between the motor is a predetermined value or more, the correction value output possible and the distance measuring apparatus of the subject, characterized in that the as the final output value.

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