JP2006300751A - Weight measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set an area less affected by an impact disturbance noise in a transition response as a weight value acquiring section to measure precisely an axle weight. <P>SOLUTION: This method sets a stable area stable with respect to a time-series sampling weight signal generated when an axle of a vehicle gets off and on a weighing table, and sets the weight value acquiring section in the time-series sampling weight signal within the stable area. The weight value acquiring section is determined along a direction capable of detecting the time-series sampling weight signal wmin0 in the vicinity of a change start point of starting a prescribed level or more of change, based on the detected time-serial sampling weight signal, when detecting the time-series sampling weight signal changed by the prescribed level or more from the time-series sampling weight signal within the stable area, and capable of going back from one end along a lapse time, using the detected time-series sampling weight signal wmin0 as the one end of the weight value acquiring section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a weight measurement method for measuring the axle weight of a vehicle traveling on a weighing platform, and more specifically, sets a weight value acquisition section for determining a weight value from a weight signal output from a load sensor of the weighing platform. It is about the method.

  In general, when an object to be weighed enters a measuring instrument (weighing platform), the weight signal output from the load sensor of the measuring instrument depends on the impact load and the weight of the object to be weighed. Appears.

  Now, as shown in FIG. 7, a vehicle 58 having three axles 55, 56, 57 gets on a weighing platform 50 supported by four load sensors 51, 52, 53, 54. Considering the case of traveling on the platform 50 and getting off, the weight of the vehicle 58 represented by the sum of the outputs of the four load sensors 51 to 54 is as shown in the graph of FIG. In FIG. 8, section A is the load of the first shaft 55, section B is the total load of the first shaft 55 and the second shaft 56, and section C is the load of the first shaft 55, the second shaft 56, and the third shaft 57. The total load, section D represents the total load of the second shaft 56 and the third shaft 57, and section E represents a weight signal due to the load of the third shaft 57. In these weight signals, a transient response attenuation signal appears when one axle gets on the weighing platform 50 or when one axle gets off the weighing platform 50.

  Here, when the vehicle 58 stops on the weighing platform 50 for a long time, the damping vibration of the weight signal converges to a stable stationary load. However, the vehicle 58 is in a traveling state and the staying time on the weighing platform 50 is In the case where the weight signal is short, as shown in FIG. 8, the weight signal changes in a vibration manner, and the vibration signal included in the weight signal does not converge.

  The axle weight (axle weight) of the first shaft 55 of the vehicle in such a traveling state is obtained by measuring the flat portion of the weight signal in the section A in FIG. Further, regarding the axial weight of the second shaft 56, the flat portion of the weight signal in the section B when the second shaft 56 gets on the weighing platform 50 is measured, and thereby the first shaft 55 and the second shaft 56 Is obtained by subtracting the weight of the first shaft 55 obtained previously. Further, regarding the axial weight of the third shaft 57, the total weight of the first shaft 55, the second shaft 56, and the third shaft 57 is obtained by measuring the flat portion of the weight signal in the section C, and this total is obtained. It is obtained by subtracting the weight of the first shaft 55 and the weight of the second shaft 56 previously obtained from the weight. In addition, as a measuring method when an axle shaft descends from the weighing platform 50, the second shaft 56 and the third shaft 57 from the flat portion of the weight signal of the section D that appears when the first shaft 55 descends from the weighing platform 50. And the weight of the third shaft 57 may be obtained by subtracting the weight of the second shaft 56 previously obtained from the total weight.

  However, when the vehicle speed is high or the distance between the axles is short, the stable time domain of the weight signal is short, so even if this weight signal is continuously output to the display, the operator and driving The person cannot correctly recognize the stable region of the weight signal, that is, the flat portion of the weight signal shown in FIG. Therefore, a correct weight value cannot be obtained by a weight measurement method in which human operation / determination is involved in reading the weight value.

  As a countermeasure against such a problem, Patent Document 1 proposes a static weight measurement method that obtains a static weight value from time-series data of a weighing value that fluctuates in a traveling vehicle.

  In the measurement method described in Patent Document 1, a sampling weight signal obtained by A / D conversion of a weight signal output from a load sensor is stored in a memory in time series, and for example, the weight of the first axis is detected. In the sampling weight signal, the maximum value or the first maximum value is detected from the time series weight signal after the first axis gets on the weighing platform, and this value is determined as the starting point of the stable region. The sampling weight signal is stored in the memory, and the sampling weight signal within the predetermined weight range from this value is used as the weight signal within the stable region, and the periodicity of the sampling weight signal within the stable region is determined, and based on the periodicity The weight value is obtained by performing arithmetic processing so as to reduce the amplitude of the noise vibration signal included in the sampling weight signal in the stable region.

  In the method described in Patent Document 1, the point at which the weight signal of the first axis completely rises is set to the maximum value or the first maximum value, and the maximum value or the maximum value is set by paying attention to the periodicity of the vibration signal. For example, a weight signal of 90% or more of the maximum value is set as a stable region, and the local maximum value of the vibration signal in the sampling weight signal in the stable region is set as an end point, and from the start point to the end point. It is defined as a weight acquisition region, and an average value in this weight acquisition region is obtained to cancel the periodic vibration component.

  As another conventional example, a method of detecting the end of the stable region in the transient response signal of the weight signal when the object to be weighed is carried on the weighing conveyor and then transferred to the next carry-out conveyor, This is proposed in Patent Document 2. This method assumes that the transient response signal has entered a stable region when it reaches a certain level or more, and after a certain amount of time has elapsed since entering this stable region, and after this sampling weight value. Compared with the generated sampling weight value that occurs sequentially, and if a deviation greater than a certain value is detected in both, it is determined that the object to be weighed has started to transfer from the weighing conveyor to the carry-out conveyor, and from the generated sampling weight value, Also, the interval between the previous sampling weight value and the sampling weight value after the specified time has been set as the weight value acquisition section.

Japanese Patent No. 2710785 Japanese Patent Publication No. 1-339536

  In the method described in Patent Document 1, the time point at which the axle is completely placed on the weighing platform and the weight signal completely rises or near the time point is determined as the starting point of the weight value acquisition. The acquisition area is determined from the rising side of the transient response signal. However, since the vehicle gets on the weighing platform in a running state, the impact of the impact load received by the weighing platform becomes larger in the first half of the transient response signal, and this impact load has a vehicle speed that is not directly related to the axle weight. Since it is affected, there is a problem that the weight signal includes a larger noise as the transient response time is earlier.

  If the weight signal is measured while the vehicle is stopped on the weighing platform, a long time for the transient response signal to sufficiently converge can be secured as the weight signal acquisition region, so the error in the first half of the transient response signal is reduced by the calculation process. can do. However, for example, as shown in FIG. 7, when measuring the weight of a vehicle 58 having three axles 55 to 57, when the vehicle speed is high, or when the distance between the first shaft 55 and the second shaft 56 is short. The time of the flat portion (section A in FIG. 8) representing the weight of the first axis 55 of the sampling weight signal is shortened, a sufficient weight signal acquisition region cannot be secured, and the first response waveform portion containing a lot of noise components Is added during the weight value calculation process, resulting in a problem that the weight value has a large error.

  On the other hand, in the method described in Patent Document 2, when the set value for determining the magnitude of the deviation is small, the noise vibration signal near the equilibrium point of the transient response signal is not caused by getting on and off of the object to be weighed. Since a signal exceeding the deviation is generated depending on the amplitude and a sufficiently long weight value acquisition area cannot be secured, a large set value must be adopted in order to avoid this situation in practical use. However, when a large value is used as the setting value for this judgment limit, the object to be weighed has already started to descend from the weighing conveyor when the deviation exceeds the predetermined value, and simply from when the predetermined value is exceeded. However, even if it is determined at the end of the weight value acquisition area with a memory sampling weight value that is one time older, there is a high possibility that a transient response has already started after any axle has descended from the weighing conveyor. Previously stored sampling weight values, including, do not represent the correct weight value. For this reason, even in the method described in Patent Document 2, there is a problem that the weight value cannot be obtained correctly.

  The present invention has been made in view of such a problem, and an area where the influence of impact disturbance noise during a transient response is small can be set as the weight value acquisition section, thereby increasing the axle weight with high accuracy. It is an object of the present invention to provide a weight measuring method that can be measured.

In order to achieve the above object, the weight measuring method according to the present invention comprises:
A stable region is set for the time-series sampling weight signal generated when the vehicle axle gets on and off the weighing platform, and a weight value acquisition section is set in the time-series sampling weight signal in this stable region. In the weight measurement method for obtaining the weight value of at least one axle on the weighing platform from the time-series sampling weight signal in the weight value acquisition section,
When a time-series sampling weight signal that has changed by a predetermined magnitude or more from the time-series sampling weight signal in the stable region is detected, a change of the predetermined magnitude or more is detected based on the detected time-series sampling weight signal. Detect a time-series sampling weight signal in the vicinity of the starting change start point, use the detected time-series sampling weight signal as one end of the weight value acquisition section, and acquire the weight value in a direction going back in time from this one end. It is characterized by defining a section.

  In the present invention, one end of the weight value acquisition section is an extreme value detected by searching in a direction going back in time from a time-series sampling weight signal that has changed by more than the predetermined magnitude, or a value in the vicinity of the extreme value. Or an extreme value one before the extreme value obtained by searching backward in the direction of time from the extreme value.

  Here, when the extreme value set at one end of the weight value acquisition section is a minimum value, the other end of the weight value acquisition section corresponding to the minimum value is also a minimum value, and the weight value acquisition section When the extreme value set at one end is a maximum value, the other end of the weight value acquisition section corresponding to the maximum value is preferably set to the maximum value.

  Further, with reference to one end of the weight value acquisition section, a time-series sampling weight signal stored in a direction going backward from the one end is traced, and a predetermined number of signals are in the stable region. It is preferable that a time-series sampling weight signal corresponding to minutes or a time point set in advance is set as the other end of the weight value acquisition section.

  According to the present invention, the sampling weight in which the weight signal of the measurement target axle is the most stable in the region where time has elapsed from the completion of the rise of the transient response signal and immediately before the axle is newly placed on the weighing platform. It is configured to capture the signal and use this weight value as one end of the weight value acquisition section, and to determine the weight value acquisition section in a direction that goes back from the end of this time, so that the impact disturbance near the start of the transient response The sampling weight signal in the time domain where the influence of noise is large can be eliminated. As a result, the weight of one axle or the total weight of a plurality of axles can be obtained with high accuracy.

  Next, specific embodiments of the weight measuring method according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a weight measuring device according to an embodiment of the present invention. In the present embodiment, as in the conventional apparatus shown in FIG. 7, a vehicle having three axles gets on a weighing platform supported by four load sensors, travels on the weighing platform and gets off. The setting method of the stable region and the weight value acquisition region will be described with reference to an example of a weight signal waveform when the first axis gets on the weighing table. The apparatus configuration diagram is omitted because it is the same as the conventional example shown in FIG.

  As shown in FIG. 1, the weight measuring device 1 of the present embodiment amplifies analog load signals corresponding to the strain amounts detected by the four load sensors (load cells) 51, 52, 53, 54. Amplifiers 2, 3, 4, 5, analog / digital converters (A / D converters) 6, 7, 8, 9 that convert the analog weight signal into digital signals, and these digital signals are the I / O circuit 10. And an arithmetic processing unit (CPU) 11 as a measurement unit that is input via the. Here, the arithmetic processing unit 11 is configured to perform required arithmetic processing by executing a predetermined program.

  The arithmetic processing unit 11 is connected to a memory 12 including a ROM, a RAM, an EEPROM and the like for storing the program and various data, and is a key switch for inputting various data via the I / O circuit 10 ( Input means) 13 and a display 14 for displaying various data.

  In the weight measuring device 1 configured as described above, the weight signal output from the load sensors 51 to 54 depends on the natural frequency of the weighing platform 50 (see FIG. 7) including the mass of the object to be weighed and the spring of the vehicle 58. It is assumed that the sampling weight signal (sampling weight value) Ws generated from the A / D converters 6 to 9 is continuously generated at a sufficiently short time interval as compared with the period of the vibration noise signal. Further, the sampling weight value Ws indicates a weight value of the object to be weighed on the weighing table 50 by previously subtracting a tare such as its own weight of the weighing table 50.

  In the present embodiment, the sampling weight value Ws represented by the sum of the outputs of the four load sensors 51 to 54 is as shown in the graph of FIG. 8 as in the conventional example. FIG. 2 shows a state in which the weight value of the object to be weighed (vehicle 58) is near zero and a change state of the weight signal when the first shaft gets on the weighing table. Has been.

A maximum value register wmax and a minimum value register wmin are provided in the memory 12, and a range of ± Wzu is set near the zero value of the sampling weight value Ws of the object to be weighed (vehicle 58) on the weighing platform 50. The sampling weight value Ws is expressed by the following expression: | Ws | <Wzu (1)
If it is satisfied, it is determined that there is no object to be weighed on the weighing table. When this equation (1) is established, it is assumed that the sampling weight value Ws is near zero. In this case, Ws is put in the maximum value register wmax, and -Wzu is put in the minimum value register wmin. Thus, each time a new sampling weight value Ws is measured, the value of wmax stored in the maximum value register wmax is compared with the value of the sampling weight value Ws. If Ws> wmax, the sampling weight value Ws is calculated. The maximum value register wmax is updated in the maximum value register wmax. Note that the minimum value register wmin is not updated and is fixed at -Wzu.

Further, every time the value of the maximum value register wmax is updated, it is determined whether or not the deviation between the value wmax and the value of the minimum value register wmin exceeds the set value Wh, in other words, whether equation (2) is satisfied. Determine whether or not.
wmax−wmin> Wh (2)
Here, the set value Wh is a weight value large enough to determine that the axle has entered the weighing platform 50 or has come off the weighing platform 50 (for example, 1/2 of the lightest axle weight). Value) is set.

In FIG. 2, if t = t ₁ and formula (2) is established, it is determined that the first shaft 55 has entered the weighing platform 50, and the first shaft 55 is placed on the weighing platform 50 as time passes from this point. Is started to detect the maximum value Wmax1 (see FIG. 3; hereinafter referred to as “first maximum value Wmax1”) of the sampling weight signal (sampling weight value) that appears when the vehicle fully enters. That is, the first maximum value Wmax1 is detected by comparing the sampling weight values Ws generated with time and stored in time series. 3 (a), (b), and (c) show the sampling weight depending on the speed of the vehicle (or the distance between the first shaft 55 and the second shaft 56) when the vehicle gets on the weighing platform while traveling. A state in which the waveform of the value Ws changes is shown. (A) is a case where an axle is slowly loaded, (b) shows a case where it is faster than (a), and (c) shows a case where it is faster than (b).

  In the present embodiment, the first local maximum value Wmax1 that is a peak signal generated when the axle enters the vehicle is avoided, and the local minimum value (first local minimum value) Wmin1 generated next to the first local maximum value Wmax1 is used as the start of the stable region. (T = 0). The reason is that the weight signal generated before the first minimum value Wmin1 includes a large impact disturbance noise due to the entering of the axle. However, the first minimum value Wmin1 is not the start point of the weight value acquisition section but the end limit point.

  Next, after detecting the first minimum value Wmin1, the sampling weight value Ws generated as time elapses is stored in the memory 12 in time series. Then, the value of the first minimum value Wmin1 is put into the minimum value register wmin and the maximum value register wmax, and the sequentially generated sampling weight value Ws is compared with the values of the minimum value register wmin and the maximum value register wmax, respectively. If> wmax, the value of Ws is put in the maximum value register wmax, and if Ws <wmin, the value of Ws is put in the minimum value register wmin. Note that the minimum value register wmin may be fixed without being updated after the value of the first minimum value Wmin1 is entered. When the first minimum value Wmin1 is detected, a value k · Wmin1 obtained by multiplying the first minimum value Wmin1 by an appropriate coefficient k (for example, k = 1.05) is put in the minimum value register wmin, and thereafter You may fix without updating.

  If a large value w <p> that exceeds the first minimum value Wmin1 and exceeds a certain value Wh is detected in the sampling weight value Ws after the first minimum value Wmin1 while repeating the above-described operation (if equation (2) is satisfied) ), It is determined that the second shaft 56 has entered the weighing platform 50, and the storage operation of the sampling weight value Ws is terminated.

  Subsequently, the time-series sampling weight value Ws stored in the memory 12 is traced back in the direction opposite to the passage of time to detect the immediately preceding minimum value wmin0. Then, the time point at which this minimum value wmin0 is generated (or a value around the minimum value or a stored sampling weight value older in time) is defined as the end of the stable region, and the start point of the weight value acquisition section (One end) is defined. The starting point of this weight value acquisition section is a maximum value in the case of a falling signal generated when the axle descends from the weighing platform 50.

  Here, in order to detect the minimum value wmin0 after detecting the weight value w <p>, the sampling weight value data stored in time series from the time when the weight value w <p> is detected is older in time. It is assumed that the value immediately before the start of the increase is the minimum value wmin0 when the value at the old time point, which has been monotonously decreasing, goes back to the increase for the first time while sequentially comparing in the direction. Hereinafter, wmin1, wmax1,... Are detected in the same manner. If Wmin1 is placed at the timing of t = 0, it is determined that wminx = Wminx if the timing of detecting wminx (x = 1, 2, 3,...) Is t = 0. it can.

  The end of the stable region is defined as described above because if the weight signal increases due to a new axle on the weighing platform, the increased weight signal can no longer be used for weighing. . In other words, if the new axle gets on the weighing platform, the sampling weight value increases monotonously, so if the minimal value immediately before this monotonous increase is detected, at least when the minimal value appears, the next axle This is because it is possible to determine that the sampling weight value is in the final region that is not affected by the above.

  The weight signal that entered the stable region does not vibrate due to normal noise but changes greatly only when the axle is getting on and off, and once the weight signal starts to change greatly due to this getting on and off the axle, the weight signal will be There is no extreme value due to monotonic decrease or monotonic increase. Therefore, it is possible to reliably determine that the extreme value immediately before the weight signal greatly changes is at least the state where the axle does not get on and off the weighing platform, and at the final timing when the transient response vibration converges to the minimum. It can be determined that there is.

  On the other hand, the end point (the other end) of the weight value acquisition section sequentially goes back in the direction opposite to the lapse of time from the start point of the weight value acquisition section (the generation point of the minimum value wmin0), and n (n = 2 in the present embodiment). It is assumed that the first local minimum value wmin2 is generated. Note that an arbitrary integer can be set as the value of n. In this way, it is possible to obtain the sampling weight value in a region where the disturbance signal is as far away as possible from the start point of the transient response and the disturbance signal converges as much as possible.

  As shown in FIG. 3B, if the second minimum value wmin2 retroactively from the minimum value wmin0 matches the first minimum value Wmin1 that is the end limit point, the end limit point is obtained as a weight value. When the second minimum value cannot be detected as shown in FIG. 3C, the generation time point of the first minimum value Wmin1 is forcibly set as the end point. To do.

  Further, the timing at which the weight signal monotonously increases when the next axle gets in is asynchronous with the period of the vibration signal, so that the vibration signal is on the way to the next minimum value as shown by symbol a in FIG. May occur. In this case, the interval b between the starting point wmin0 of the weight value acquisition section and the immediately preceding minimum value wmin1 is shorter than one period c of the vibration signal. Considering this, it is preferable to designate the starting point of the weight value acquisition section as wmin1 instead of wmin0. However, when a sufficient time has not elapsed from the end limit point Wmin1, and the stable region is short as shown in FIG. 3C, and Wmin1 = wmin1, wmin0 must be set as the start point.

  In the prior art (Patent Document 1), the vicinity of the completion of the rise of the transient response signal caused by the loading of the axle on the weighing platform is set as the start point of the stable region, and the weight value acquisition interval in the direction in which time passes from this start point However, according to the present embodiment, the weight of the measurement target axle in the region where time has elapsed since the completion of the rise of the transient response signal and immediately before the axle is newly placed on the weighing platform. Since it is configured to capture the sampling weight value where the signal is most stable, this weight value is used as the starting point of the weight value acquisition section, and the weight value acquisition section is determined in a direction that goes back in time from this starting point. The time-domain sampling weight signal, which is greatly affected by the impact disturbance noise near the start of the transient response, can be eliminated, and the measurement accuracy can be improved compared to the conventional method. A.

  In the present embodiment, the second minimum value wmin2 is traced back from the start point wmin0 of the weight value acquisition section. However, the time-series sampling weight value storage value is traced back from the start point. The Nth (N is a predetermined constant) may be the end point.

  In the present embodiment, since the integral period of the vibration wave is taken in the weight value acquisition section, and the average value of the sampling weight values in this weight value acquisition section is obtained, the vibration component can be efficiently removed. As the weight value acquisition section, it is preferable to set the section so that the end point is also a minimum value when the start point is a minimum value, and the end point is also a maximum value when the start point is a maximum value. By doing so, the weight value can be obtained with high accuracy.

  Further, when the speed of the vehicle 58 is extremely slow, it takes time until the next axle gets in, so that the detection of the weight value w <p> is delayed, and the sampling weight value Ws is stored until the time of the detection. Requires a huge amount of memory. Therefore, a limit is set on the number of stored sampling weight values Ws, and when the number of stored constant values M is reached after detection of the first minimum value Wmin1, the sampling weight value at that time is automatically treated as the weight value w <p>. Try to end the memory task. Then, after detecting the weight value w <p>, an operation for detecting wmin0, wmin1,. In this way, even if the next axle has entered when the stored number has just reached M and the weight signal has started to rise significantly, the start point wmin0 can be obtained avoiding the influence.

Count start point of the storage number M may be the first local maximum value Wmax1 the first minimum value Wmin1 previously, may be a time point of t = t ₁ shown in FIG. However, it is desirable to start counting after the sampling weight value enters the stable region because a certain number of sampling weight values in the stable region can be secured. Here, since the sampling time interval is constant, a certain number of sampling weight values can be regarded as a sampling weight value for a certain time. Accordingly, the setting of the maximum memory number M can be regarded as equivalent to the timer setting.

  However, when the weight value w <p> is determined by the number M, as shown in FIG. 5, the sampling weight signal as in the case where the weight value w <p> is determined by the determination formula (2). Is not necessarily a monotonous increase process. Therefore, when the weight value w <p−1> adjacent to the weight value w <p> in the oldest direction is larger than the weight value w <p>, the oldest stored value is sequentially traced and the maximum value wmax0 is set. After the detection, the starting point wmin0 of the weight value acquisition section is detected.

  In the above description, the method of obtaining the axle weight when the axle is put on the weighing platform is described. However, when the axle is lowered from the weighing platform 50, the weight of the axle remaining on the weighing platform is obtained. A similar idea can be applied.

  As shown in FIG. 6, when the front axle descends from the weighing platform 50, the weight signal greatly decreases, a negative peak value (first minimum value) Wmin1 appears, and then the first maximum in the positive direction. The value Wmax1 appears. In this case, the first maximum value Wmax1 and later are determined as the stable region, and the sampling weight values after this stable region are stored in the memory 12 in time series. Thereafter, when the axle to be weighed descends from the weighing platform 50, a sampling weight value w <p> that is smaller than the first maximum value Wmax1 by a set value Wh or more appears, so the sampling weight value is stored here. Is detected, and the maximum value wmax0 is detected by going back in time with the data stored in the memory 12, and the maximum value wmax0 is set as the starting point of the weight value acquisition interval, and the maximum value wmax0 is traced back. The weight value is calculated from the sampling weight value up to the second maximum value wmax2. Note that the starting point of the stable region may be delayed by another cycle to be the second maximum value wmax2.

The block diagram of the weight measuring apparatus which concerns on one Embodiment of this invention. Waveform diagram showing the change in weight signal before and after the first axis of the vehicle enters the weighing platform Waveform diagram showing how the weight signal changes depending on the speed of the vehicle or the distance between the first axis and the second axis when the vehicle gets on the weighing platform while traveling Waveform diagram explaining the case where the weight signal suddenly rises before reaching the minimum value The figure explaining how to determine the weight value acquisition section when determining the end point of the stable region from the number of memories Waveform diagram showing changes in weight signal when the axle gets off the weighing platform Schematic configuration diagram of a conventional weight measuring device Waveform diagram showing changes in weight signal when the vehicle travels and moves on the weighing platform

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Weight measuring apparatus 11 Arithmetic processor 12 Memory 50 Weighing platforms 51-54 Load sensor 55 1st axis | shaft 56 2nd axis | shaft 57 3rd axis | shaft 58 Vehicle

Claims (4)

A stable region is set for the time-series sampling weight signal generated when the vehicle axle gets on and off the weighing platform, and a weight value acquisition section is set in the time-series sampling weight signal in this stable region. In the weight measurement method for obtaining the weight value of at least one axle on the weighing platform from the time-series sampling weight signal in the weight value acquisition section,
When a time-series sampling weight signal that has changed by a predetermined magnitude or more from the time-series sampling weight signal in the stable region is detected, a change of the predetermined magnitude or more is detected based on the detected time-series sampling weight signal. Detect a time-series sampling weight signal in the vicinity of the starting change start point, use the detected time-series sampling weight signal as one end of the weight value acquisition section, and acquire the weight value in a direction going back in time from this one end. A weight measuring method characterized by defining a section.   One end of the weight value acquisition section is an extreme value detected by searching backward in the direction from the time-series sampling weight signal that has changed by more than the predetermined magnitude, or a value in the vicinity of the extreme value, or the extreme value The weight measurement method according to claim 1, wherein the extreme value is one extreme before the extreme value obtained by searching backward in the direction of time from the value.   When the extreme value set at one end of the weight value acquisition section is a local minimum value, the other end of the weight value acquisition section corresponding to the local minimum value is also a local minimum value. The weight measuring method according to claim 2, wherein when the set extreme value is a maximum value, the other end of the weight value acquisition section corresponding to the maximum value is also set to the maximum value.   Based on one end of the weight value acquisition section, the time-series sampling weight signal stored in the direction going back from the one end is traced, and within the stable region and set to a preset number. The weight measurement method according to claim 1, wherein a time-series sampling weight signal corresponding to or at a preset time length is set as the other end of the weight value acquisition section.

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