Loading weight measuring device and loading weight measuring method

Abstract

To provide a loading weight measuring device and a loading weight measuring method capable of accurately measuring the loading weight of a vehicle immediately after the vehicle stops.SOLUTION: A control unit 21 of a dead weight meter 20 includes: a first control unit that samples a load signal output by a sensor with predetermined sampling intervals; a second control unit that calculates a determination value as a difference between a first weight value extracted for determination from sampling data sampled by the first control unit and a second weight value being a one preceding value of the first weight value; a third control unit that determines whether or not the determination value is a predetermined threshold value or more; a fourth control unit that, when it is determined that the determination value is the threshold value or more, calculates a difference weight as a difference between a third weight value obtained at a time point after a predetermined time elapses from a time point of sampling the second weight value and the second weight value; and a fifth control unit that calculates a current loading weight on the basis of the past loading weight stored in a storage unit and the difference weight.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a loaded weight measurement device and a loaded weight measurement method. [Background technology]

[0002] Generally, when a vehicle used to transport goods is operated with a load exceeding the permitted weight (i.e., overloaded), it not only leads to traffic accidents such as rollovers and poor braking performance, but also contributes to the deterioration of the vehicle and damage to the road surface. For this reason, the load weight on the loading platform is legally limited and mandated by vehicle operation regulations.

[0003] Conventionally, the load weight of a cargo vehicle has been measured by placing the vehicle on a platform scale known as a kankan (weight scale). However, this method requires high equipment costs and a large installation space. For this reason, in recent years, load weight measurement devices (so-called weight scales) that are mounted on the vehicle itself to measure the load weight have been developed. In this type of weight scale, weight measurement sensors such as strain gauge sensors are attached to both the left and right ends of the front and rear axles, and the load weight is measured by the sum of the outputs of these sensors, which are proportional to the loads acting on the front, rear, left, and right tires.

[0004] However, with the above-mentioned sensors, the output value can slowly change due to temperature changes in the axles before and after the vehicle is stopped, even though the load weight does not change (temperature drift, etc.). This causes a problem in that if work is continued while the vehicle is stopped, the load weight fluctuates as cargo is being carried onto the vehicle.

[0005] In order to solve the above-mentioned problems, Patent Document 1 proposes a drift correction method in which a signal output by a strain gauge sensor attached to a vehicle as a physical quantity corresponding to the load on the vehicle is corrected by a correction value corresponding to the temperature measured by the sensor at the attachment point of the sensor, and the vehicle's load weight is calculated based on the signal corrected by this correction value. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-064593 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although the method disclosed in Patent Document 1 corrects for temperature drift, it takes time for the drift to settle after correction, making it difficult to handle situations where loading occurs immediately after stopping, such as in compactor trucks. As such, there is room for improvement in conventional drift correction methods, and it is desirable for vehicles equipped with weight scales to be configured to be able to handle situations where loading and unloading occurs immediately after stopping.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a load weight measurement device and a load weight measurement method that can measure the load weight of a vehicle with high accuracy immediately after the vehicle has stopped. [Means for solving the problem]

[0009] In order to achieve the above object, the load weight measuring device according to the present invention comprises: A load weight measurement device for measuring the load weight of a vehicle, a control unit that measures the load weight based on a load signal output by a sensor in response to a strain amount of the axle caused by a load applied to the vehicle being transmitted to the axle; a memory unit that stores the measured loaded weight, The control unit a first control unit that samples the load signal at a predetermined sampling interval; a second control unit that calculates a determination value that is the difference between a first weight value extracted for determination from the sampling data sampled by the first control unit and a second weight value immediately preceding the first weight value; a third control unit that determines whether the determination value is equal to or greater than a predetermined threshold value; a fourth control unit that calculates a differential weight, which is a difference between a third weight value at a time when a predetermined time has elapsed since the second weight value was sampled, and the second weight value, when it is determined that the determination value is equal to or greater than the threshold value; and and a fifth control unit that calculates a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. It must be a load weight measuring device.

[0010] In order to achieve the above-mentioned object, a method for measuring a load weight according to the present invention includes: A method for measuring a load weight of a vehicle, comprising: a first step of sampling a load signal output by a sensor in response to a strain amount of the axle caused by a load applied to the vehicle being transmitted to the axle at a predetermined sampling interval; a second step of calculating a judgment value which is the difference between a first weight value extracted for judgment from the sampled sampling data and a second weight value immediately preceding the first weight value; a third step of determining whether the determination value is equal to or greater than a predetermined threshold value; a fourth step of calculating a differential weight, which is the difference between a third weight value at a time when a predetermined time has elapsed since the second weight value was sampled, and the second weight value, when the determination value is determined to be equal to or greater than the threshold value; and a fifth step of calculating a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. It must be a method of measuring loaded weight. [Effects of the Invention]

[0011] According to the present invention, the load weight of a vehicle can be measured with high accuracy immediately after the vehicle comes to a stop.

[0012] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a loaded weight measurement system including a loaded weight measurement device (weight meter) according to one embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of the sensor unit. [Figure 3] FIG. 3 is a diagram showing an example of the configuration of a loaded weight measuring device (weight meter). [Figure 4] FIG. 4 is a flowchart showing an example of a loaded weight measurement method. [Figure 5] FIG. 5 is a flowchart showing an example of a loaded weight measurement method (continuation of FIG. 4). [Figure 6] FIG. 6 is a graph for explaining the loaded weight measurement method. [Figure 7] FIG. 7 is a flowchart showing an example of a method for setting a threshold value. [Figure 8] FIG. 8 is a flowchart showing an example of a method for setting the convergence time. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A loaded weight measuring device and a loaded weight measuring method according to an embodiment of the present invention will be described below with reference to the drawings.

[0015] The present invention is not limited to the embodiments described below, and can be appropriately modified, improved, etc. In addition, the material, shape, size, number, location, etc. of each component in the embodiments described below are arbitrary and not limited as long as they can achieve the present invention.

[0016] <Load Weight Measurement System 100> First, the loaded weight measurement system 100 will be described with reference to Figures 1 to 3. As shown in Figure 1, the loaded weight measurement system 100 is configured to include a plurality of sensor units 10 provided on both the front and rear axles 2 of a vehicle 1, and a weight meter 20 (corresponding to the "loaded weight measurement device" of the present invention) mounted on the vehicle 1 for measuring and displaying the loaded weight of the vehicle 1 based on load signals from the plurality of sensor units 10.

[0017] In the loaded weight measurement system 100, the vehicle 1 is a cargo transport vehicle such as a compactor or truck, and when the vehicle 1 stops at a predetermined location, workers load and unload cargo onto a loading platform or the like (not shown) of the vehicle 1. Then, the weight meter 20 measures the load weight for a measurement section defined between when the vehicle 1 stops and when it starts traveling, i.e., the section loaded and unloaded during one stop.

[0018] In addition, in the load weight measurement system 100, springs (not shown, for example, leaf springs) are interposed between the left and right ends of both the front and rear axles 2 of the vehicle 1 and the front, rear, left and right locations of the vehicle frame (not shown, for example, a loading platform frame), and each of the sensor units 10 provided on both the front and rear axles 2 outputs a load signal corresponding to the amount of strain on the axle 2 caused when the load applied to the vehicle 1 is transmitted to the axle 2 via the spring.

[0019] Therefore, after loading and unloading of the load, for example, an operator operates the input unit 23 (see FIG. 3) of the weight meter 20, which causes the sensor unit 10 to output a load signal corresponding to the amount of strain on the axle 2 caused by the loading and unloading of the load, and the load weight is measured by the weight meter 20 based on this load signal. The measured load weight is displayed on a display unit 22 (not shown) of the weight meter 20 provided in the driver's seat, cabin, etc. of the vehicle 1, so that the operator can see it.

[0020] [Sensor unit 10] The sensor unit 10 is, for example, a known one, and outputs a load signal according to the amount of strain on the axle 2 as described above. As shown in Fig. 2, the sensor unit 10 is configured to include a sensor 11, an adjustment unit 12, a voltage / frequency conversion unit 13 (hereinafter also referred to as "V / F conversion unit 13"), a weight meter connector 14, and a setting connector 15. In the sensor unit 10, an ASIC is used for the adjustment unit 12.

[0021] The sensor 11 is a strain-type sensor that outputs a load signal according to the amount of strain on the axle 2. The adjustment unit 12 has the function of amplifying and correcting the load signal output by the sensor 11. The adjustment unit 12 is configured to have, for example, an A / D conversion unit that converts the load signal input from the sensor 11 into a digital load signal, a correction unit that corrects the digital load signal, an amplification unit that amplifies the digital load signal, and a D / A conversion unit that converts the digital load signal into an analog load signal. In this example, the adjustment unit 12 is realized by an ASIC, but the present invention is not limited to this and various other embodiments such as a DSP or a CPU can be used.

[0022] The V / F conversion unit 13 has a function of converting the load signal (voltage) adjusted by the adjustment unit 12 into a frequency. The weight meter connector 14 is connected to the weight meter 20 and has a function of transmitting the load signal converted into a frequency by the V / F conversion unit 13 to the weight meter 20. The setting connector 15 enables connection to a setting device (not shown) and is connected to the setting device when setting the sensor unit 10.

[0023] [Weight scale 20] As described above, the weight meter 20 measures and displays the load weight of the vehicle 1 based on the load signal from the sensor unit 10. As shown in FIG. 3 , the weight meter 20 includes a control unit 21, a display unit 22, an input unit 23, an I / F unit 24, and a storage unit 25.

[0024] The control unit 21 has a function of measuring the load weight of the vehicle 1 based on a load signal output by the sensor unit 10 in response to the amount of strain in the axle 2 caused when the load applied to the vehicle 1 is transmitted to the axle 2 .

[0025] The control unit 21 includes a first control unit that samples the load signal output by the sensor at a predetermined sampling interval, a second control unit that calculates a judgment value, which is the difference between a first weight value extracted for judgment from the sampling data sampled by the first control unit and a second weight value immediately before the first weight value, a third control unit that determines whether the judgment value is equal to or greater than a predetermined threshold, a fourth control unit that calculates a differential weight, which is the difference between the third weight value and the second weight value at a predetermined time after the second weight value was sampled, if the judgment value is determined to be equal to or greater than the threshold, a fifth control unit that calculates the current load weight based on the past load weights and differential weights stored in the memory unit, a sixth control unit that sets the threshold, and a seventh control unit that sets the convergence time. In this example, the first to seventh control units are configured as an integrated unit, but they may also be separate units.

[0026] The display unit 22 has a function of displaying the loaded weight of the vehicle 1 measured by the control unit 21. The input unit 23 has a measurement start button (not shown), a measurement end button (not shown), a measurement value reset button (not shown), etc., and can perform input related to the operation and operation control of the weight meter 20. The I / F unit 24 is an interface that connects to the weight meter connector 14, and is compatible with various connector shapes and signal formats depending on the application. The memory unit 25 stores threshold values, convergence time, loaded weight information of the vehicle 1, etc., which will be described later.

[0027] The weight meter 20 has a measurement mode for measuring the load weight of the vehicle 1, a threshold setting mode for setting a threshold value used when measuring the load weight, and a convergence time setting mode for setting a convergence time used when measuring the load weight.Each of these modes is switched by, for example, an input operation to the input unit 23, and an operation corresponding to the selected mode is performed.

[0028] When measuring the load weight of the vehicle 1, the load signal output by the sensor unit 10 usually drifts due to temperature changes in the axles before and after the vehicle 1 is stopped, and if no measures are taken to prevent this drift and cargo is loaded or unloaded while the vehicle is stopped, the weight value measured by the gravity meter 20 will fluctuate. On the other hand, when cargo is loaded or unloaded onto the vehicle 1, the measured weight value fluctuates in accordance with the weight of the cargo.

[0029] Therefore, in the measurement mode, it is determined whether the fluctuation in the measured weight value is due to drift or due to loading / unloading, and the loaded weight of the vehicle 1 is measured. Therefore, in the measurement mode, a threshold value is used to determine whether the fluctuation in the measured weight value is due to loading / unloading.

[0030] That is, the threshold value is a value for determining whether or not a change in the measured weight value is due to loading or unloading, and this threshold value is set in the threshold value setting mode.

[0031] However, when loading or unloading cargo onto the vehicle 1, the vehicle 1 shakes to some extent, and the load signal output by the sensor unit 10 drifts due to this shaking of the vehicle 1, and similar to temperature drift, the weight value measured by the gravity meter 20 fluctuates. For this reason, in the measurement mode, the load weight is measured using the weight value after the drift caused by the shaking of the vehicle 1 has converged, that is, after the convergence time has elapsed.

[0032] That is, the convergence time is the time required for the drift caused by the shaking of the vehicle 1 to converge, and in the convergence time setting mode, this convergence time is set.

[0033] <Method of measuring load weight> Next, an example of the operation of the load weight measurement system 100, including an example of a load weight measurement method, will be described with reference to Figures 4 to 6. This load weight measurement method is used to measure the load weight for a section where loading and unloading has occurred during one stop, and is realized, for example, by the control unit 21 executing a predetermined program. Note that the following operation is performed, for example, when the weight meter 20 is in measurement mode.

[0034] The control unit 21 determines whether or not measurement start information has been detected (Sp1). If measurement start information has been detected (Yes in Sp1), the processing of the control unit 21 proceeds to Sp2. On the other hand, if measurement start information has not been detected (No in Sp1), the processing of the control unit 21 repeats Sp1. For example, the measurement start information is detected when an operator performs an input operation (for example, pressing the measurement start button) on the input unit 23 of the weight meter 20.

[0035] The control unit 21 acquires the load signals output from each sensor unit 10 (Sp2), and calculates the weight value of the vehicle 1 based on each acquired load signal (Sp3). Sp2 and Sp3 are performed by, for example, well-known methods. In Sp3, the control unit 21 samples each load signal at a predetermined sampling interval.

[0036] When the control unit 21 detects amplitude spread from the sampling data (see FIG. 6), it calculates the difference (determination value) between the first weight value P1 for determination and the second weight value P2 immediately preceding the first weight value P1 (Sp4).

[0037] The control unit 21 determines whether the difference (determination value) between the first weight value P1 and the second weight value P2 is equal to or greater than a threshold value (Sp5). That is, in Sp5, the control unit 21 determines whether the fluctuation in the measured weight value is due to the loading or unloading of cargo onto the vehicle 1. If the determination value is equal to or greater than the threshold value, i.e., if it is determined that the fluctuation in the measured weight value is due to unloading (Yes in Sp5), the control unit 21 proceeds to Sp6. On the other hand, if the determination value is less than the threshold value, i.e., if it is determined that the fluctuation in the measured weight value is not due to unloading (No in Sp5), the control unit 21 proceeds to Sp9.

[0038] The control unit 21 calculates the difference (differential weight) between the third weight value P3 obtained at the time when the convergence time has elapsed since the second weight value P2 was measured from the sampling data (see FIG. 6) and the second weight value P2 (Sp6). The differential weight calculated in this way is the weight of the load unloaded from the vehicle 1.

[0039] The control unit 21 calculates the current load weight based on the past load weight and the difference (differential weight) between the third weight value P3 and the second weight value P2 (Sp7). That is, the current load weight can be calculated by adding or subtracting the differential weight calculated as the weight of the load to or from the past load weight.

[0040] The control unit 21 displays the calculated current load weight on the display unit 22 (Sp8), thereby enabling the worker to visually confirm the current load weight.

[0041] The control unit 21 determines whether or not measurement end information has been detected (Sp9). If measurement end information has been detected (Yes in Sp9), the processing of the control unit 21 proceeds to Sp10. On the other hand, if measurement end information has not been detected (No in Sp9), the processing of the control unit 21 proceeds to Sp4. For example, the measurement end information is detected when an operator performs an input operation on the input unit 23 of the weight meter 20 (for example, pressing the measurement end button).

[0042] The control unit 21 records the current load weight being displayed on the display unit 22, for example, in the memory unit 25 (Sp10). Note that in this example, the current load weight is configured to be stored in the memory unit 25, but it may also be recorded within the control unit 21, for example.

[0043] The control unit 21 determines whether or not measurement value reset information has been detected (Sp11). If measurement value reset information has been detected (Yes in Sp11), the processing of the control unit 21 proceeds to Sp10. On the other hand, if measurement end information has not been detected (No in Sp11), the processing of the control unit 21 ends. For example, the measurement value reset information is detected when an operator performs an input operation on the input unit 23 of the weight meter 20 (for example, pressing the measurement value reset button).

[0044] The control unit 21 displays "0 kg" on the display unit 22 (Sp12), and then ends this processing flow.

[0045] <How to set the threshold> Next, an example of a method for setting the threshold value will be described with reference to Fig. 7. This method for setting the threshold value is performed in advance before the load weight measurement system 100 is put into actual operation, and is realized, for example, by executing a predetermined program by the control unit 21. Note that the following operation is performed, for example, when the weight meter 20 is in threshold value setting mode.

[0046] The control unit 21 detects that the vehicle 1 has stopped (Sp21), and measures "fluctuations in the weight values ​​measured by the weight meter 20" from the time of detection until the expected operation time has elapsed (Sp22). During this measurement time, the control unit 21 samples the load signals acquired from each sensor unit 10 at a predetermined sampling interval.

[0047] The control unit 21 detects amplitude spread from the sampling data and sets a threshold based on the weight value where the amount of fluctuation in the weight value per minute period of time is maximum (Sp23). More specifically, the point where the slope is greatest is extracted from the sampling data, and the absolute value of the maximum value (or minimum value if negative) of the extracted point is set as the threshold. By setting the threshold in this manner, when the load weight measurement system 100 is actually operated, if the fluctuation in the weight value measured by the weight meter 20 is equal to or greater than the threshold, it can be determined that the fluctuation is not due to temperature drift or the like, but is due to loading or unloading of cargo onto the vehicle 1.

[0048] The accuracy of the threshold is ensured by repeating the above-described processing flow (especially Sp21 to Sp22) multiple times. However, when the above-described processing flow is repeated multiple times, the maximum value is found from multiple sample data in Sp23, and this is set as the threshold.

[0049] <How to set the convergence time> Next, an example of a method for setting the convergence time will be described with reference to Fig. 8. This method for setting the convergence time is performed in advance before the load weight measurement system 100 is put into actual operation, and is realized, for example, by executing a predetermined program by the control unit 21. Note that the following operation is performed, for example, when the weight meter 20 is in the convergence time setting mode.

[0050] The control unit 21 samples the load signals acquired from each sensor unit 10 at a predetermined sampling interval, and detects that each sensor unit 10 is in a steady state from the sampling data (Sp31). In this setting, in order to set the convergence time of the fluctuation in weight value caused by the shaking of the vehicle 1 associated with the loading and unloading of cargo onto the vehicle 1 as described above, first, each sensor unit 10 needs to be in a steady state.

[0051] When it is detected in Sp1 that each sensor unit 10 is in a steady state, a worker loads a heavy object onto the vehicle 1. The control unit 21 measures the weight value of the loaded heavy object (Sp32). Then, when the shaking of the vehicle 1 caused by the loading of the heavy object subsides, the control unit 21 detects that each sensor unit 10 is in a steady state (Sp33).

[0052] The control unit 21 sets the convergence time to the time required from the time the heavy object is loaded until the steady state is detected (Sp34). By setting the convergence time in this manner, the measurement accuracy of the weight meter 20 is improved when the load weight measurement system 100 is actually used.

[0053] The accuracy of the convergence time is ensured by performing the above-described processing flow (especially Sp31 to Sp33) multiple times. However, if the above-described processing flow is performed multiple times, the required time (convergence time) is calculated from multiple sample data in Sp34, and the longest of these is set as the convergence time.

[0054] <Actions and Effects> As described above, according to this embodiment, by determining whether the determination value is equal to or greater than a predetermined threshold, it is possible to determine whether a change in weight value is due to the loading or unloading of cargo onto or from the vehicle 1. Then, when the determination value is equal to or greater than the threshold, i.e., when it is determined that cargo has been loaded or unloaded onto the vehicle 1, the weight of the cargo can be determined by calculating the differential weight, which is the difference between the second weight value P2 and the third weight value P3. Therefore, the current load weight can be calculated based on the past load weight and the differential weight. In this way, according to this embodiment, the load weight of the vehicle 1 can be measured without waiting for the convergence of temperature drift, etc. In other words, this embodiment can accurately measure the load weight of the vehicle 1 immediately after the vehicle 1 has stopped.

[0055] Furthermore, according to this embodiment, the load signal is sampled at a predetermined sampling interval from the time when the vehicle 1 stops until the time when the assumed operation time has elapsed, and the threshold value is set based on the weight value at which the amount of fluctuation in the weight value per minute time from the sampling data is maximum. By setting the threshold value in this manner, if the fluctuation in the weight value measured by the weight meter 20 is equal to or greater than the threshold value, it can be determined that the fluctuation is not due to temperature drift or the like, but is due to loading or unloading of cargo onto the vehicle 1.

[0056] Furthermore, according to this embodiment, the predetermined time is the time it takes for the shaking of the vehicle 1 caused by the loading of cargo onto the vehicle 1 to subside, so that the measurement accuracy of the weight meter 20 can be improved.

[0057] <Additional Notes> Here, the features of the embodiments of the loaded weight measurement device and the loaded weight measurement method according to the present invention will be briefly summarized and listed below in [1] to [4].

[0058] [1] A load weight measurement device (weight meter 20) for measuring the load weight of a vehicle (1), a control unit (21) for measuring the load weight based on a load signal output from a sensor (11) in response to a strain of the axle (2) caused by a load applied to the vehicle (1) being transmitted to the axle; and a memory unit (25) that stores the measured loaded weight, The control unit (21) a first control unit (21 in this example) that samples the load signal at a predetermined sampling interval; a second control unit (21 in this example) that calculates a judgment value that is the difference between a first weight value extracted for judgment from the sampling data sampled by the first control unit and a second weight value immediately preceding the first weight value; a third control unit (21 in this example) that determines whether the determination value is equal to or greater than a predetermined threshold value; a fourth control unit (21 in this example) that calculates a differential weight, which is the difference between a third weight value at a time when a predetermined time has elapsed since the second weight value was sampled, and the second weight value, when it is determined that the determination value is equal to or greater than the threshold value; and a fifth control unit (21 in this example) that calculates a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. Load weight measuring device (weight gauge 20).

[0059] [2] The loaded weight measurement device (weight meter 20) described in [1] above, The threshold value is set before the load weight is measured, The control unit (21) further includes a sixth control unit (21 in this example) that sets the threshold value, The sixth control unit (21 in this example) The vehicle (1) is detected to be stopped, and the load signal is sampled at a predetermined sampling interval from the time when the vehicle (1) is stopped until the time when the estimated operation time of the load weight measuring device has elapsed, and the threshold value is set based on the weight value at which the amount of fluctuation in the weight value per minute time is maximum from the sampling data. Load weight measuring device (weight gauge 20).

[0060] [3] The loaded weight measuring device (weight meter 20) according to [1] or [2] above, The predetermined time is set before the load weight is measured, and is the time until the vibration of the vehicle caused by the loading of the load on the vehicle subsides. Load weight measuring device (weight gauge 20).

[0061] [4] A method for measuring a load weight of a vehicle, comprising: a first step of sampling a load signal output by a sensor in response to a strain amount of the axle caused by a load applied to the vehicle being transmitted to the axle at a predetermined sampling interval; a second step of calculating a judgment value which is the difference between a first weight value extracted for judgment from the sampled sampling data and a second weight value immediately preceding the first weight value; a third step of determining whether the determination value is equal to or greater than a predetermined threshold value; a fourth step of calculating a differential weight, which is the difference between a third weight value at a time when a predetermined time has elapsed since the second weight value was sampled, and the second weight value, when the determination value is determined to be equal to or greater than the threshold value; and a fifth step of calculating a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. Load weight measurement method.

[0062] According to the configurations [1] and [4] above, by determining whether the judgment value is equal to or greater than a predetermined threshold, it is possible to determine whether the fluctuation in the weight value is due to the loading or unloading of cargo onto or from the vehicle. Then, when the judgment value is equal to or greater than the threshold, i.e., when it is determined that cargo has been loaded onto or unloaded from the vehicle, the weight of the cargo can be determined by calculating the differential weight, which is the difference between the second weight value and the third weight value. Therefore, the current load weight can be calculated based on the past load weight and the differential weight. In this way, according to this configuration, the load weight of the vehicle can be measured without waiting for the convergence of temperature drift, etc. In other words, this configuration can accurately measure the load weight of the vehicle immediately after the vehicle stops.

[0063] According to the configuration [2] above, the load signal is sampled at a predetermined sampling interval from the time the vehicle stops until the time the expected operation time of the load weight measurement device has elapsed, and a threshold is set based on the weight value at which the amount of fluctuation in the weight value per minute time from the sampling data is maximum. By setting the threshold in this manner, if the fluctuation in the weight value measured by the load weight measurement device is equal to or greater than the threshold, it can be determined that the fluctuation is not due to temperature drift or the like, but is due to loading or unloading of cargo onto or from the vehicle.

[0064] According to the above configuration [3], the predetermined time is the time required for the vibration of the vehicle caused by the loading of the load on the vehicle to subside, thereby improving the measurement accuracy of the load weight measuring device. [Explanation of symbols]

[0065] 1 vehicle 2 axles 10 Sensor Unit 11 Sensors 12 Adjustment section 13 V / F conversion section 14 Weight gauge connector 15 Setting connector 20 Weight scale 21 Control section 22 Display section 23 Input section 24 I / F section 25 Memory section 100 Load Weight Measurement System P1 First weight value P2 Second weight value P3 Third weight value

Claims

1. A load weight measurement device for measuring the load weight of a vehicle, a control unit that measures the load weight based on a load signal output by a sensor in response to a strain amount of the axle caused by a load applied to the vehicle being transmitted to the axle; a memory unit that stores the measured loaded weight, The control unit a first control unit that samples the load signal at a predetermined sampling interval; a second control unit that calculates a determination value that is the difference between a first weight value extracted for determination from the sampling data sampled by the first control unit and a second weight value immediately preceding the first weight value; a third control unit that determines whether the determination value is equal to or greater than a predetermined threshold value; a fourth control unit that calculates a differential weight, which is a difference between a third weight value at a time point when a predetermined time has elapsed since the time point when the second weight value was sampled, and the second weight value, when it is determined that the determination value is equal to or greater than the threshold value; and and a fifth control unit that calculates a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. Load weight measuring device.

2. The load weight measuring device according to claim 1, The threshold value is set before the load weight is measured, the control unit further includes a sixth control unit that sets the threshold value; The sixth control unit is When the vehicle is detected to be stopped, the load signal is sampled at a predetermined sampling interval from the time when the vehicle is stopped until the time when the expected operation time of the load weight measuring device has elapsed, and the threshold value is set based on the weight value at which the amount of fluctuation in the weight value per minute time is maximum from the sampling data. Load weight measuring device.

3. The loaded weight measuring device according to claim 1 or 2, The predetermined time is set before the load weight is measured, and is the time until the vibration of the vehicle caused by the loading of the load on the vehicle subsides. Load weight measuring device.

4. A method for measuring a load weight of a vehicle, comprising: a first step of sampling, at a predetermined sampling interval, a load signal output by a sensor in response to a strain amount of the axle caused by a load applied to the vehicle being transmitted to the axle; a second step of calculating a judgment value which is the difference between a first weight value extracted for judgment from the sampled sampling data and a second weight value immediately preceding the first weight value; a third step of determining whether the determination value is equal to or greater than a predetermined threshold value; a fourth step of calculating a differential weight, which is a difference between a third weight value at a time point when a predetermined time has elapsed since the time point when the second weight value was sampled, and the second weight value, when the determination value is determined to be equal to or greater than the threshold value; and a fifth step of calculating a current loaded weight based on the past loaded weight stored in the storage unit and the differential weight. Load weight measurement method.

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