JP2016205846A - Measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement device with which it is possible to prevent the deterioration of measurement accuracy even when there is residual vibration from a preceding measured object and set a measurement parameter for which the residual vibration is taken into account, and to perform measurement stably with high accuracy.SOLUTION: In a measurement device 1, a measurement unit 72 includes a vibration extraction unit 120 for extracting, upon receiving a weighing signal when a prescribed sample is inputted as an object W to be measured, a vibration component that occurs when the rear end of the sample separates from the take-out end of a conveyance unit 3, and a vibration superposition unit 121 for generating a superposed weighing signal in which the vibration component is superposed at a prescribed position of the weighing signal. A control unit 74 sets, on the basis of a measurement single derived from the superposed weighing signal by applying signal processing thereto, a condition for signal processing in the measurement unit 72 when the object W to be measured is brought in.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a weighing device for weighing an object to be weighed such as meat, fish, processed food, and medicine, for example.

  Conventionally, in a production line for food, etc., the articles incorporated in the production line are sequentially carried in from the front stage, weighed while transporting the carried in articles, and carried out to the rear stage or removed from the production line by the sorting unit A weighing device is used.

  In such a weighing device, when the preceding object to be weighed is transferred from the weighing conveyor to the subsequent conveyor, a residual vibration is generated in the weighing conveyor. Since this residual vibration is included in the weighing signal of the subsequent object to be measured when the distance from the subsequent object to be measured is narrow, there is a problem that a measurement error is generated.

  On the other hand, as a conventional weighing device, a residual vibration is sampled in advance, and this residual vibration is subtracted from a weighing signal of a subsequent object to be measured, thereby preventing a measurement error due to the influence of the residual vibration. (See Patent Document 1).

Japanese Patent No. 3779443

  However, what is described in Patent Document 1 is a configuration in which residual vibration data is sampled and stored in advance using a sample article as an average object to be measured, and the influence value is subtracted to correct the sample article. There is a problem that the difference between the residual vibration and the residual vibration during actual measurement directly leads to a decrease in correction accuracy. Since the residual vibration is an unsteady transient response, fluctuations in the state of conveyance of the object to be weighed (for example, the angle of the object to be weighed with respect to the conveying direction) will appear as fluctuations in the residual vibration waveform, and the object to be weighed in In the case where the transport state varies or changes with time, the influence of the residual vibration changes accordingly, and the correction effect cannot be sufficiently exhibited. For this reason, the measuring device described in Patent Document 1 is difficult to stably correct the influence of residual vibration, and is not practical.

  Therefore, the present invention has been made to solve the above-described conventional problems, and is designed to prevent the measurement accuracy from deteriorating even if there is residual vibration of the preceding object to be measured, and to take into account the residual vibration. It is an object of the present invention to provide a weighing device capable of setting parameters and performing stable and accurate weighing.

  The weighing device according to the present invention receives a workpiece to be sequentially loaded from the front stage, and carries a conveyance section that carries the workpiece to a subsequent stage, and a detection section that detects a carry-in of the weighing object to the conveyance section and outputs a detection signal. A weighing unit that outputs a weighing signal according to a load acting on the transport unit, a signal processing unit that processes the weighing signal under predetermined signal processing conditions, and outputs a weighing signal and a measured value, and the signal processing And a control unit for setting conditions, wherein the weighing unit receives the weighing signal when a predetermined sample product as the object to be weighed is input, and a rear end of the sample product is A vibration extracting unit that extracts a vibration component generated when the conveying unit is separated from a carry-out end of the conveying unit; and a vibration superimposing unit that generates a superimposed weighing signal in which the vibration component is superimposed on a predetermined position of the weighing signal. The controller includes the superimposing scale. Signal on the basis of the weighing signal is a signal processed and output, said and sets the signal processing conditions in the metering unit when the objects to be weighed is transported.

  With this configuration, the signal processing condition (measurement parameter) is set using the superimposed weighing signal in which the vibration component (residual vibration) generated when the rear end of the sample product is separated from the carry-out end of the transport unit is superimposed on a predetermined position. Can be set. For this reason, by using a small number of sample products such as one to several, it is possible to set signal processing conditions that take into account the residual vibration for the objects to be actually loaded sequentially, without being affected by the residual vibration. Stable and accurate weighing.

  Further, in the weighing device according to the present invention, the transport unit is configured by a weighing conveyor to which the weighing unit is connected and a running conveyor for carrying the object to be weighed into the weighing conveyor, and the control unit is configured by the sample After the product is transferred from the run-up conveyor to the weighing conveyor, the weighing conveyor is temporarily stopped, and the measured value output from the weighing unit while the weighing conveyor is temporarily stopped is used as the actual measured value of the sample product. The signal processing condition is set based on the acquired and the actual weighing value and the weighing signal output by signal processing of the superimposed weighing signal.

  With this configuration, the actual weighing value of the sample product can be acquired while the weighing conveyor is temporarily stopped, and the stability can be determined as the convergence value of the weighing signal. It is possible to set signal processing conditions that allow accurate weighing taking into account the deviation from the measured value.

  Further, in the weighing device according to the present invention, the vibration superimposing unit generates the superimposed weighing signal superimposed at positions corresponding to a plurality of different workpiece pitches, and the control unit is configured to include the plurality of superimposed weighing signals. The signal processing conditions in the weighing unit are set when the object to be weighed is loaded on the basis of weighing values calculated under a plurality of signal processing conditions.

  With this configuration, a measurement value is calculated under a plurality of signal processing conditions for each of a plurality of superimposed weighing signals superimposed on a position corresponding to a range of fluctuation of an assumed work pitch (a carry-in interval of an object to be weighed), Based on the measured value, the optimum processing condition is selected from the signal processing conditions that have been processed to calculate the measured value, and the signal processing condition is set. Weighing can be performed.

  The weighing device according to the present invention further includes a storage unit that stores the optimum processing condition at each position to be superimposed calculated by the control unit, and the control unit selects the optimum processing condition from the storage unit. The signal processing conditions are set.

  With this configuration, it is possible to select the optimum processing condition from the storage unit and set the signal processing condition. For example, when the carry-in of the object to be weighed is detected, the work pitch with the preceding object to be weighed is acquired. In this case, the optimum processing condition can be always set as the signal processing condition and the weighing can be performed, and the weighing can be performed more stably and accurately.

  The present invention can provide a weighing device that can set a weighing parameter in consideration of the residual vibration of a preceding object to be measured and can perform stable weighing with high accuracy.

It is a perspective view which shows the outline | summary of the weighing | measuring device which concerns on one embodiment of this invention. It is a block diagram which shows the internal structure of the weighing | measuring device which concerns on one embodiment of this invention. It is a figure which shows the structure of the measurement part of the weighing | measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows the time change of a weighing signal. (A) is a figure which shows the weighing signal containing residual vibration, and the residual vibration waveform extracted from this weighing signal, (b) is a figure which shows a superimposed weighing signal. It is a figure which shows the filter selection table classified by position which the control part of the weighing | measuring device which concerns on one embodiment of this invention refers. It is a figure explaining selection of the filter condition which the control part of the measuring device concerning one embodiment of the present invention performs.

  Hereinafter, embodiments of a weighing device according to the present invention will be described with reference to the drawings. 1 to 7 show an embodiment of a weighing device according to the present invention.

  First, an outline of the weighing device 1 will be described. As shown in FIG. 1, the weighing device 1 includes an apparatus main body 2, a transport unit 3, and a carry-in sensor 4. A sorting unit 5 is connected to the subsequent stage of the weighing device 1.

  The weighing device 1 is installed on the downstream side of the belt conveyor 14 constituting a part of the production line, and is to be weighed for meat, fish, processed foods, pharmaceuticals, etc. that are sequentially carried in the direction of arrow A at predetermined intervals. The weight of the object W is measured, and the obtained measurement value (hereinafter referred to as a measurement value) is output as a measurement result.

  In addition, the weighing device 1 determines the weighing object W as a non-defective product or a defective product depending on whether or not the measured value is within the range of the reference value. Furthermore, the weighing device 1 determines the weight rank of the object to be weighed W corresponding to a plurality of reference values based on the obtained measured values.

  In addition, the measurement result, the pass / fail determination result, and the weight rank determination result are displayed on the display unit 10 and are output to the selection unit 5 connected to the subsequent stage of the weighing device 1. The sorting unit 5 distributes the objects to be weighed W according to the measurement result output from the weighing device 1, the pass / fail determination result, and the weight rank determination result.

  Next, a detailed configuration of the weighing device 1 will be described. As shown in FIGS. 1 and 2, the apparatus main body 2 includes a weighing unit 21, a general control unit 7, a display unit 10, a setting unit 11, and a storage housing 2 a that stores these units. Has been.

  The transport unit 3 transports the object W to be weighed in from the belt conveyor 14 in the direction of arrow A under predetermined transport conditions. The object to be weighed W is conveyed by being accelerated or decelerated so as to have an optimum speed for measurement by the running conveyor 31, further conveyed by the weighing conveyor 32, and the weight is measured by the weighing unit 21 while being conveyed. It has become so.

  The weighing conveyor 32 conveys an object to be weighed under predetermined conveyance conditions. In addition, the object to be weighed W is further transported to the sorting unit 5 in the subsequent stage after the weighing and is distributed.

  The transport unit 3 includes a running conveyor 31 and a weighing conveyor 32. The run-up conveyor 31 performs the run-up of the object to be weighed W before the object to be weighed W conveyed from the preceding belt conveyor 14 moves to the weighing conveyor 32, and includes two rollers 31a and 31c, And an endless conveying belt 31b wound around the roller.

  The weighing conveyor 32 is supported by the upper part of the weighing unit 21 for weighing the workpiece W, and includes two rollers 32a and 32c, an endless conveying belt 32b wound around these rollers, and a roller 32c. It is comprised with the motor which is not shown in figure which drives. The roller 32c is rotationally driven by a motor.

  The carry-in sensor 4 is disposed between the run-up conveyor 31 and the weighing conveyor 32, and includes a transmission photoelectric sensor including a pair of light projecting units 4a and light receiving units 4b. The light projecting unit 4a is disposed on the apparatus main body unit 2 side of the conveyor belt 32b. The light receiving unit 4b is disposed on the other side surface of the conveyance belt 32b so as to face the light projecting unit 4a.

  The carry-in sensor 4 indicates that the object to be weighed W has started to be loaded when the object to be weighed W passes between the light projecting part 4a and the light receiving part 4b and the light receiving part 4b is shielded by the object to be weighed W. Is supposed to be detected. The carry-in start signal detected by the carry-in sensor 4 is output to the general control unit 7 in the apparatus main body 2.

  The weighing unit 21 is a load sensor that supports the weighing conveyor 32 and outputs a weighing signal based on the load of the workpiece W. The weighing unit 21 has a configuration of an electric resistance wire type balance (load cell), and measures the load applied to the weighing unit 21 while the workpiece W is being conveyed by the weighing conveyor 32.

  The weighing section 21 has a metallic strain body (not shown) and a bridge circuit made of an electric resistance wire (strain gauge) attached to a stress concentration portion of the strain body. The weighing unit 21 receives a load and deforms the stress concentration portion of the strain generating body, whereby the electric resistance wire is compressed and the electric resistance value is decreased, and the electric resistance wire is expanded and the electric resistance value is increased. Since the resistance value of the bridge circuit changes, the detection signal that detects the change in resistance value is amplified, and the signal formed through the filter circuit or the like is output as a weighing signal obtained by measuring the load.

  The strain body has a fixed end and a free end, and the fixed end is fixed to the fixed base, and the lower end of the support portion 21a that receives the load of the weighing conveyor 32 is connected to the free end. . As the weighing unit 21, an electromagnetic balance type balance (force balance) or a differential transformer type balance may be used.

  The general control unit 7 includes a measuring unit 72, a storage unit 73, a control unit 74, a quality determination unit 76, and a mode switching unit 77.

  As shown in FIG. 3, the weighing unit 72 includes a vibration extraction unit 120, a vibration superimposition unit 121, a filter processing unit 123, and a measurement value calculation unit 124, and a weighing signal from the weighing unit 21 is not illustrated. A digital signal is converted by the converter, and the digitized weighing signal is filtered by the filter processing unit 123 in accordance with the weighing parameter as a signal processing condition, and then the measured value is calculated by the measured value calculation unit 124. The measurement parameters include a filter condition used in the filter processing unit, a measurement condition used in the measurement value calculation unit 124, and the like. Here, the filter processing unit 123 and the measurement value calculation unit 124 will be described, and the vibration extraction unit 120 and the vibration superimposition unit 121 will be described later.

  The filter processing unit 123 stores a plurality of low-pass filters of different types and characteristics as band-pass filters, and performs filter processing on the weighing signal from the weighing unit 21 using a low-pass filter selected from the plurality of low-pass filters. And only the low-frequency component of the weighing signal is passed as a signal-processed weighing signal.

  Note that there may be one low-pass filter selected by the filter processing unit 123 or a combination of a plurality of low-pass filters. As this low-pass filter, there are a FIR (Finite Impulse Response) filter and an IIR (Infinite Impulse Response) filter.

  The FIR filter is a finite impulse response filter that outputs a fixed time (finite time) when an impulse response waveform is input, and the IIR filter is an infinite impulse response that outputs an attenuation waveform of the impulse response waveform infinitely. It is a filter.

  Here, the FIR filter constitutes a low-pass filter that passes a predetermined low-frequency component with respect to the weighing signal converted into a digital signal by the A / D converter 96, and performs a simple averaging process or a known window function. The weighted averaging process used is performed.

  The IIR filter is an analog that directly receives a weighing signal (analog weighing signal) from the weighing unit 21 and outputs a processed signal to the A / D converter 96 using hardware whose characteristics can be changed, such as a switched capacitor filter. You may comprise by a filter and you may comprise by the digital filter which receives the digital weighing signal from the A / D converter 96.

  The measured value calculation unit 124 calculates (measured in grams) the measured value of the object W based on the weighing signal filtered by the filter processing unit 123. Individual measurement values calculated by the measurement value calculation unit 124 are stored in the storage unit 73 as calculation data.

  Further, in the weighing unit 72, after a predetermined reference time Tk has elapsed as shown in FIG. 5B, after the carry-in sensor 4 detects that the object to be weighed W has been carried into the weighing conveyor 32, A measured value is calculated for the object W to which the weighing signal is output from the weighing unit 21.

  Here, the reference time Tk is detected by the loading sensor 4 that the object to be weighed W has started to be loaded onto the weighing conveyor 32, and then the weighing object W is completely transferred to the weighing conveyor 32, and further from the weighing unit 21. This is the time required for the output weighing signal to stabilize.

  More specifically, the reference time Tk is the speed of the weighing conveyor 32 (m / min), the length of the weighing conveyor 32 in the direction of arrow B (mm), and the length of the weighing object W in the direction of arrow B (the direction of conveyance of the object W) ( mm), the size of the workpiece W, the processing capacity of the line, and other conditions.

  As shown in FIG. 4, when the reference time Tk elapses, the object to be weighed W moves by L1 from the carry-in start detection position Po to reach the mass measurement position Ps, and the weighing is performed after the mass measurement position Ps. Is called.

  Moreover, the calculation of the measurement value is performed during the measurement time Ts (see FIG. 4) after the reference time Tk elapses until the workpiece W is carried out from the weighing conveyor 32.

  In the weighing unit 72, inspection conditions (parameters) such as the measurement range, measurement capability, and inspection accuracy are selected according to the type (particularly size) of the object to be weighed W. Depending on the type of the weighing object W, for example, the measurement range is selected from 6 g to 600 g, and the measurement capability is selected at a maximum of 150 pieces / min.

  In this case, the reference time Tk per object W is set to a minimum of 400 msec, and the reference time Tk may be 400 msec or more. It is set according to capacity, production and other conditions.

  The storage unit 73 is composed of a storage medium or the like, and corresponds to a predetermined transport condition of the object W to be weighed by the weighing conveyor 32 and a condition parameter including a weighing parameter used by the weighing unit 72 to the type of the object W to be weighed. Let me remember.

  The storage unit 73 stores a conveyance speed and LPF (Low Pass Filter) characteristics corresponding to each product number assigned to each product type of the object to be weighed W. The storage unit 73 stores upper and lower reference values as a non-defective range for determining the quality of the object W.

  Here, the conveyance speed is the speed of the conveyance unit 3 that conveys the workpiece W, and the LPF characteristic indicates what kind of characteristic the low-pass filter is, and the non-defective range is determined as non-defective. This is the range of the measured value of the object W to be weighed.

  The stored information is stored in advance by a setting operation from the setting unit 11 or connection with an external device. The storage unit 73 stores various data such as measurement values and pass / fail judgment results.

  The control unit 74 reads out predetermined transport conditions and predetermined signal processing conditions from the storage unit 73 according to the type of the object to be weighed W, and controls the weighing conveyor 32 respectively.

  The control unit 74 controls the transport unit 3 by sequentially switching condition parameters corresponding to a plurality of types stored in the storage unit 73. In addition, the control unit 74 drives and controls the rotation speed (rpm) of a motor (not shown) so as to control the conveyance speed of the workpiece W by the conveyance unit 3.

  The pass / fail determination unit 76 is configured by a determination circuit or the like, and determines and outputs a pass / fail determination result based on a comparison between the measured value calculated by the weighing unit 72 and the pass / fail determination reference value.

  Specifically, when receiving the measurement value of the object W output from the weighing unit 72, the quality determination unit 76 reads the upper limit value and the lower limit value stored in advance in the storage unit 73, and calculates the measured object. The weighing value of the object W is compared with the upper limit value and the lower limit value, respectively, and it is determined whether or not the weighing value of the object W is within the allowable range determined by the upper limit value and the lower limit value. Yes.

  The determination result determined by the pass / fail determination unit 76 is output to the display unit 10 and displayed as a non-defective product or a defective product. The determination result is output to the sorting unit 5 connected to the subsequent stage of the weighing device 1 so that the object to be weighed W is sorted as a non-defective product or a defective product. Further, the determination result is output to the storage unit 73, and the determination result for each object W is stored.

  The mode switching unit 77 issues a command to the control unit 74 and switches the operation mode of the weighing device 1 between the main operation mode and the setting mode. Here, the actual operation mode is a normal operation mode in which the weighing apparatus 1 calculates the measurement value of the workpiece W and determines whether it is good or bad. The setting mode is used for setting various parameters, This is an operation mode for confirming whether or not the operation in the operation mode can be normally performed.

  As shown in FIG. 1, the display unit 10 is provided at the upper end of the apparatus main body 2 on the transport unit 3 side, and is configured by a display device such as a liquid crystal display. The display unit 10 displays the operation state of the weighing device 1, the measurement value of the object W, the pass / fail judgment result, and displays related to parameter setting and operation check. The display unit 10 and the setting unit 11 may be integrated as a touch panel so that numbers, characters, and the like displayed on the display unit 10 are input from the setting unit 11 by a touch operation.

  The sorting unit 5 is connected to the subsequent stage of the weighing device 1 and includes a sorting mechanism unit 5a and a conveyor belt 5b. The sorting mechanism unit 5a is configured by, for example, an extrusion type sorting mechanism.

  The sorting mechanism unit 5a only needs to be able to sort good products and defective products, and may be configured by a sorting mechanism such as a flipper mechanism, a dropout mechanism, or an air jet mechanism. The sorting mechanism unit 5a is configured to transfer the workpiece belt W to the workpiece W determined to be defective while the workpiece W transported from the upstream weighing conveyor 32 is being transported in the arrow B direction by the transport belt 5b. 5b is pushed out in the lateral direction and jet air is sprayed, and the defective object W is discharged from the conveying belt 5b and is distinguished from the non-defective object W by sorting. Yes.

  The conveyor belt 5b is composed of a roller 5c, a roller (not shown) disposed opposite to the roller 5c, and an endless conveyor belt wound around these rollers. The weighing object W is conveyed downstream at a predetermined speed.

  Furthermore, as shown in FIG. 3, the weighing device 1 of the present embodiment includes a vibration extraction unit 120 and a vibration superimposition unit 121 in the weighing unit 72, and the residual vibration processing condition when the operation mode is the setting mode. Works according to. When the operation mode is the actual operation mode, the vibration superimposing unit 121 does nothing, and the weighing signal from the weighing unit 21 passes through the filter processing unit 123 as it is.

  The vibration extraction unit 120 is separated from the carry-out end of the sample product from the digitized weighing signal obtained by transporting one sample product to the run-up conveyor 31 and the weighing conveyor 32 as an object W before actual operation. A vibration component (residual vibration) generated sometimes is extracted.

  Here, since the residual vibration is generated when transferring from the weighing conveyor 32 to the subsequent conveyor, the extraction condition in the residual vibration processing conditions (detection timing of the loading sensor 4, from the loading sensor 4 to the rear end of the weighing conveyor 32). ), The residual vibration is extracted. For example, as shown in FIG. 5A, the residual vibration S2 of the sample product is separated from the vibration waveform of the sample product weighing signal S1 by a predetermined interval from the timing position at which the carry-in sensor 4 detects the sample product. Since the vibration occurs at the position, the position from the position where the residual vibration starts to the position where the residual vibration converges is extracted. The weighing signal of the sample product and the extracted residual vibration are temporarily stored in a memory (not shown).

  The vibration superimposing unit 121 generates a superimposed weighing signal in accordance with a superimposition condition (superimposition position) in the residual vibration processing conditions. For example, as shown in FIG. 5B, a superimposed weighing signal like S3 in which the residual vibration S2 of the sample product is superposed at a predetermined position on the weighing signal S1 of the sample product is generated.

  The vibration superimposing unit 121 generates a plurality of superimposed weighing signals with different superposition positions to be superimposed so as to correspond to a plurality of work pitches (loading intervals of the objects to be weighed W). The range of the superposition position is a position where the residual vibration affects the measurement value. For example, if the vicinity of the start point C of the measurement period Ts in FIG. 4 is set as the superposition position, the residual position is near the start of the measurement period Ts. Vibration is superimposed.

  In addition, the control unit 74 sets the weighing parameter for the superimposed weighing signal corresponding to a plurality of work pitches within the range of the superimposed position in order to set the optimum weighing parameter for calculating the measured value in the actual operation. The measurement value is acquired while changing, the optimum condition of the measurement parameter is derived based on the acquired measurement value, and the optimum measurement parameter is set for calculating the measurement value in actual operation.

  Specifically, the control unit 74 creates a position-specific filter selection table shown in FIG. In this filter selection table for each position, the number of measurement points and the number of filter taps at the amount of advance (D-1 or D-2) from the weighing signal timing D in FIG. For the measured values obtained by changing the values, a comparison value (for example, a difference value, a ratio, etc.) with the measured value of the sample product is tabulated. The measured value of the sample product is obtained under predetermined filtering conditions (for example, a measured value with a relatively large number of taps and a measurement point D, or an average of measured values at the measurement point) for the sample product weighing signal. The measured value can be the measured value of the sample product. Further, the measurement value of the sample product may be set in advance from the setting unit.

  The control unit 74 sets the maximum value among the comparison values of a plurality of work pitches for each filter processing condition (filter type, measurement point, number of filter taps) so as to skew the created filter selection table by position in the work pitch direction. Is determined as an allowable comparison value indicating the limit of the allowable range in the filtering condition, and the filtering condition having the smallest allowable comparison value among the allowable comparison values of the plurality of filtering conditions is set as the optimum weighing parameter. Set. Here, when the comparison values are tabulated based on the filter processing conditions in order to obtain the allowable comparison values, for example, a table as shown in FIG. 7 is obtained.

  The position-specific filter selection table of FIG. 7 uses the filter processing condition 101, the filter processing condition 103, and the filter processing condition 105 as the number of taps 1, 3, and 5 of the measurement point D for the filter 1, for example. The number of taps 1, 3, and 5 are arranged in the vertical direction as filter processing conditions 111, filter processing conditions 113, filter processing conditions 115,..., And the work pitches WP1, WP2, and WP3 are arranged in the horizontal direction. Yes.

  In FIG. 7, the comparison value of the work pitch WP1 of the filter processing condition 101 is 0.3, the comparison value of the work pitch WP2 is 0.2, the comparison value of the work pitch WP3 is 0.2, and the maximum value of the comparison value is Since the work pitch WP1 is 0.3, the allowable comparison value of the filter processing condition 101 is 0.3. Similarly, when an allowable comparison value is obtained for each filter processing condition, the allowable comparison value of the filter processing condition 103 is 0.5, the allowable comparison value of the filter processing condition 105 is 0.4, and the allowable comparison value of the filter processing condition 111 is 0. .4, the allowable comparison value of the filter processing condition 113 is 0.5, and the allowable comparison value of the filter processing condition 115 is 0.6. Then, the filter processing condition (here, the filter processing condition 101 where the allowable comparison value is 0.3) in which the allowable comparison value of each filter processing condition is the minimum value is selected and set as the optimum measurement parameter.

  In this way, that is, the allowable comparison value that is the maximum value of the comparison value obtained by comparing the measurement value obtained from the superimposed weighing signal corresponding to a plurality of workpiece pitches with the measurement value of the sample product is assumed to be the workpiece. Select the filter processing condition that minimizes the weighing error range because the weighing value obtained by filtering the superimposed weighing signal with residual vibration superimposed within the pitch fluctuation range is the weighing error range in the filtering processing condition. The measurement error can be minimized.

  The control unit 74 selects a filter processing condition that minimizes the comparison value for each work pitch in the position-specific filter selection table shown in FIG. 6 and stores it in the storage unit as an optimum measurement parameter for each work pitch. More preferably, during operation, the work pitch is acquired using the carry-in sensor 4, the optimum measurement parameter corresponding to the acquired work pitch is read from the storage unit, the measurement parameter is set, and the measurement value is calculated.

  In this way, during operation, it is possible to use the optimum weighing parameter corresponding to the work pitch for each object W and taking into account the residual vibration, and the measurement value of the object W to be weighed more stably and accurately. Can be calculated.

  Further, the weighing conveyor 32 temporarily stops after the sample product is transferred from the run-up conveyor 31 to the weighing conveyor 32, and temporarily acquires the weighing signal of the sample product while the weighing conveyor 32 is temporarily stopped. Thereafter, the weighing conveyor 32 reversely conveys, returns the sample product to the running conveyor 31, and again conveys the sample product to the running conveyor 31 and the weighing conveyor 32 so that the vibration extraction unit 120 acquires the residual vibration. Is preferred.

  That is, in dynamic measurement in which weighing is performed while the object to be weighed W is conveyed, even if the same object to be weighed W is measured a plurality of times, the weighing values are not equal, and deviation may occur. However, this weighing can be avoided by temporarily stopping the weighing conveyor 32, and for example, an accurate actual weighing value of the sample product can be obtained.

  Further, the weighing conveyor 32 conveys one object W multiple times, and the vibration extraction unit 120 outputs the weighing data respectively output from the weighing unit 21 when the sample product is conveyed to the weighing conveyor 32 multiple times. A signal may be acquired. For example, when the user returns the sample product carried out from the weighing conveyor 32 onto the run-up conveyor 31, a desired number of measurements are performed, and the accuracy of the comparison value in the position selection table can be improved.

  In the present embodiment, it has been described that the optimum weighing parameter is set from a plurality of superimposed weighing signals. However, there is a device that makes the object to be weighed W at regular intervals in the previous stage, and the work pitch of the object to be weighed W is constant. In such a case, a weighing parameter which is an optimum processing condition in one superimposed weighing signal may be set.

  As described above, in the weighing apparatus 1 according to the present embodiment, the weighing unit 72 receives a weighing signal when a predetermined sample product as the object to be weighed W is inserted, and receives the rear end of the sample product. A vibration extraction unit 120 that extracts a vibration component generated when it is separated from the carry-out end of the transport unit 3, a vibration superimposing unit 121 that generates a superimposed weighing signal in which the vibration component is superimposed on a predetermined position of the weighing signal, The control unit 74 is configured to set the signal processing conditions in the weighing unit 72 when the workpiece W is carried in based on the weighing signal that is output after the superimposed weighing signal is processed. .

  With this configuration, signal processing conditions (measurement parameters) using a superimposed weighing signal in which a vibration component (residual vibration) generated when the rear end of the sample product is separated from the carry-out end of the transport unit 3 is superimposed on a predetermined position. Can be set. For this reason, by using a small number of sample products such as one to several, it is possible to set signal processing conditions that take into account the residual vibration for the objects to be actually loaded sequentially, without being affected by the residual vibration. Stable and accurate weighing.

  Further, in the weighing device 1 according to the present embodiment, the transport unit 3 includes a weighing conveyor 32 to which the weighing unit 21 is connected and a run-up conveyor 31 that carries the object W to the weighing conveyor 32, and includes a control unit. 74, temporarily stops the weighing conveyor 32 after the sample product is transferred from the run-up conveyor 31 to the weighing conveyor 32, and the measured value output from the weighing unit 72 while the weighing conveyor 32 is temporarily stopped is used as the actual value of the sample product. Signal processing conditions are set based on a measurement signal that is acquired as a measurement value and is output after the actual measurement value and the superimposed weighing signal are processed.

  With this configuration, the actual weighing value of the sample product can be acquired while the weighing conveyor 32 is temporarily stopped, and the stability can be determined as the convergence value of the weighing signal. It is possible to set signal processing conditions that allow accurate weighing taking into account the deviation from the measured value.

  In the weighing device 1 according to the present embodiment, the vibration superimposing unit 121 generates a superimposed weighing signal superimposed at positions corresponding to a plurality of different workpiece pitches, and the control unit 74 includes a plurality of superimposed weighings. A signal processing condition in the weighing unit 72 is set when an object to be weighed W is loaded based on a measurement value calculated under a plurality of signal processing conditions for each of the signals.

  With this configuration, a measured value is calculated under a plurality of signal processing conditions for each of a plurality of superimposed weighing signals superimposed at a position corresponding to a variation range of an assumed work pitch (a carry-in interval of the workpiece W). Since the optimum processing conditions are selected from the signal processing conditions that have been processed to calculate the measurement values from the measurement values and the signal processing conditions are set, stable measurement with minimum accuracy is ensured. It can be carried out.

  In addition, the weighing device 1 according to the present embodiment includes a storage unit 73 that stores the optimal processing conditions at each position to be superimposed calculated by the control unit 74, and the control unit 74 selects the optimal processing conditions from the storage unit 73. Then, a signal processing condition is set.

  With this configuration, it is possible to select the optimum processing condition from the storage unit 73 and set the signal processing condition. For example, when the carry-in of the workpiece W is detected, the work pitch with the preceding workpiece W is acquired. By doing so, it is possible to always perform weighing by setting the optimum processing condition as the signal processing condition, and it is possible to perform weighing more stably and with high accuracy.

  As described above, the weighing device according to the present invention has an effect that it can set the optimum inspection conditions taking into account the residual vibration of the preceding object to be weighed, and can accurately calculate the measured value. It is useful as a weighing device for weighing objects to be weighed such as fish, processed foods, and pharmaceuticals.

DESCRIPTION OF SYMBOLS 1 Weighing device 3 Conveying part 21 Weighing part 31 Run-up conveyor 32 Weighing conveyor 72 Weighing part 73 Memory | storage part 74 Control part 120 Vibration extraction part 121 Vibration superimposition part W Weighing object

Claims (4)

A transport unit (3) for receiving an object to be weighed (W) sequentially carried in from the front stage and carrying it out to the rear stage;
A detection unit (4) for detecting the carry-in of the object to be measured into the transfer unit and outputting a detection signal;
A weighing unit (21) for outputting a weighing signal in accordance with a load acting on the conveying unit;
A weighing unit (72) that performs signal processing of the weighing signal under predetermined signal processing conditions and outputs a weighing signal and a weighing value;
A control unit (74) for setting the signal processing conditions;
In a weighing device comprising
The weighing unit receives the weighing signal when a predetermined sample product as the object to be weighed is inserted, and a vibration component generated when the rear end of the sample product is separated from the carry-out end of the transport unit A vibration extracting unit (120) for extracting the vibration component, and a vibration superimposing unit (121) for generating a superimposed weighing signal in which the vibration component is superimposed on a predetermined position of the weighing signal,
The control unit sets the signal processing condition in the weighing unit when the object to be weighed is loaded based on the weighing signal output by the signal processing of the superimposed weighing signal. Weighing device. The transport unit is composed of a weighing conveyor (32) to which the weighing unit is connected and a running conveyor (31) for carrying the object to be weighed into the weighing conveyor,
The control unit temporarily stops the weighing conveyor after the sample product has been transferred from the run-up conveyor to the weighing conveyor, and outputs the measurement value output from the weighing unit while the weighing conveyor is temporarily stopped. 2. The signal processing condition is set based on the actual measurement value obtained as a sample product, and based on the actual measurement value and the measurement signal output by signal processing of the superimposed weighing signal. The metering device described. The vibration superimposing unit respectively generates the superimposed weighing signals superimposed at positions corresponding to a plurality of different work pitches,
The control unit determines the signal processing condition in the weighing unit when the object to be weighed is loaded based on a measured value calculated under a plurality of signal processing conditions for each of the plurality of superimposed weighing signals. 3. The weighing device according to claim 1, wherein the weighing device is set. A storage unit (73) for storing the optimum processing condition at each position to be superimposed calculated by the control unit;
The weighing apparatus according to claim 3, wherein the control unit selects the optimum processing condition from the storage unit and sets the signal processing condition.

Images