Weighing device, foreign matter inspection system for weighing device, and foreign matter inspection method for weighing device

Abstract

To allow easy inspection for foreign matter inserted in a weighing device.SOLUTION: A weighing device comprises : a weighing table 20 on which an inspection weight is placed; a weighing sensor 51 detecting the weight to be placed on the weighing table; a control arithmetic part 60 calculating a weighed value on the basis of an output value of the weighing sensor; and an output part 41 outputting the weighed value. The control arithmetic part 60 is configured to: set on the weighing table 20 a plurality of areas partitioned by at least one line passing through the center; instruct an operator to sequentially place the inspection weight on each of the plurality of areas and the center part; weigh the inspection weights placed on each site; compare a difference between maximum value and minimum value of weighed values on the plurality of areas and the center part to a predetermined threshold to determine whether foreign matter is inserted; and output the determination result.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to foreign object inspection of a weighing device, and more specifically to a weighing device having a foreign object inspection function, a foreign object inspection system for a weighing device, and a foreign object inspection method for a weighing device. [Background technology]

[0002] Conventionally, large-sized weighing scales known as barrier-free scales that allow users to weigh themselves while sitting in a wheelchair are known as weighing devices (see, for example, Patent Document 1). For such weighing scales used for medical purposes, it is extremely important that they can perform accurate measurements. For this reason, hospitals and medical facilities periodically or before use check that the correct value is displayed by placing, for example, a plastic bottle filled with water or a weight of about 20 kg on each of the four corners.

[0003] One of the reasons why a weighing scale may display an inaccurate reading is when a foreign object, such as a pen, gets stuck between the weighing platform and the floor on which it is placed (hereinafter referred to as a foreign object being trapped). If a foreign object gets stuck, when the weighing platform sinks due to the load being weighed during weighing, it may come into contact with the foreign object and cause an error in the weighing value. Because large weighing scales are heavy, it is not easy to lift them and check for trapped foreign objects, so it is necessary to detect and remove any trapped foreign objects during the above inspection. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-9453 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above inspection, which requires loading and unloading a weight of approximately 20 kg, is extremely hard work. Furthermore, when using a weight of approximately 20 kg for a large scale with a capacity of 100 to 200 kg, an abnormality in the weighing value due to a pinched foreign object may not be detected if the foreign object is small or only slightly trapped. In fact, when the person being weighed is an adult male or in a wheelchair, the weight may be several times larger than 20 kg, for example, 60 kg or more. However, a small pinched foreign object that only comes into contact with the weighing platform and causes an error when such a relatively large load is applied cannot be detected using a weight of approximately 20 kg. However, it is not practical to perform an inspection using a weight with a mass greater than 20 kg.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a weighing device that makes it possible to easily check for trapped foreign objects. [Means for solving the problem]

[0007] In order to achieve the above object, a weighing device according to one aspect of the present invention has the following configuration. 1. A weighing platform on which an inspection load is placed, a weighing sensor that detects the load placed on the weighing platform, a control and calculation unit that calculates a weighing value based on the output value of the weighing sensor, and an output unit that outputs the weighing value, wherein the control and calculation unit sets multiple areas on the weighing platform divided by at least one line segment passing through the center, and uses the output unit to instruct an operator to sequentially place the inspection load on each of the multiple areas and on the center, weighs the inspection load placed on each of the multiple areas and on each position in the center, compares the difference between the maximum and minimum weighing values ​​in the multiple areas and on the center with a predetermined threshold value to determine whether a foreign object has been trapped, and outputs the result of the determination.

[0008] 2. In the above aspect 1, if it is determined in the determination that a foreign object is trapped, it is also preferable to determine that the position of the trapped foreign object is in a position corresponding to the region showing the minimum value.

[0009] 3. In the above aspects 1 and 2, it is also preferable that the output unit is equipped with a display unit, and that the multiple areas of the weighbridge are each marked with a different mark, and that the control and calculation unit is configured to instruct the worker on the order in which to place the inspection loads by displaying a schematic diagram of the weighbridge on the display unit and displaying mark images on the schematic diagram corresponding to the positions at which the inspection loads should be placed.

[0010] 4. In the above aspects 1 to 3, the output unit is equipped with a display unit, and each of the multiple areas set on the weighbridge is marked with a different mark, and the control and calculation unit is configured to output the result of the judgment to the worker by displaying a schematic diagram of the weighbridge on the display unit and a mark image corresponding to the pinch position of the foreign object judged on the schematic diagram.

[0011] 5. In the above aspects 1 to 4, the weighbridge is rectangular, and four areas corresponding to the four corners are set on the weighbridge, which are partitioned by two perpendicular lines passing through the center of the weighbridge.

[0012] Furthermore, a foreign object inspection system for a weighing device according to another aspect of the present invention has the following configuration. 6. A weighing device comprising: a weighing platform on which an inspection load is loaded; a weighing sensor that detects the load loaded on the weighing platform; a control and calculation unit that calculates a measurement value based on the output value of the weighing sensor; and a communication unit; and an inspection module comprising a communication unit that can send and receive information to and from the weighing device, a module calculation unit, and an output unit; wherein the weighing device transmits the measurement value to the inspection module in accordance with instructions from the inspection module, the module calculation unit sets multiple areas on the weighing platform divided by at least one line segment passing through the center, and uses the output unit to instruct an operator to load the inspection load sequentially on each of the multiple areas and on the central portion, calculates the measurement value of the inspection load loaded at each position in each of the multiple areas and on the central portion, compares the difference between the maximum and minimum of the measurement values ​​in the multiple areas and on the central portion with a predetermined threshold to determine whether a foreign object has been trapped, and outputs the result of the determination.

[0013] A foreign object inspection method for a weighing device according to another aspect of the present invention has the following configuration. 7. A method for inspecting whether a foreign object is trapped in a weighing device, which is executed by a computer and which comprises a weighing platform on which an inspection load is loaded, a weighing sensor that detects the load loaded on the weighing platform, a control and calculation unit that calculates a measurement value based on the output value of the weighing sensor, and a communication unit, the method comprising the steps of: setting a plurality of areas on the weighing platform, which are divided by at least one line segment passing through the center; instructing an operator to sequentially load the inspection load on each of the plurality of areas and on the center portion; obtaining the measurement value of the inspection load loaded on each position of the plurality of areas and on the center portion; comparing the difference between the maximum and minimum measurement values ​​in the plurality of areas and on the center portion with a predetermined threshold value to determine whether a foreign object has been trapped; and outputting the result of the determination. [Effects of the Invention]

[0014] According to the above aspect, it is possible to easily check whether any foreign matter has become caught between the weighing platform of the weighing device and the installation surface. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing the appearance of a weighing device according to a first embodiment. FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a control block diagram of the weighing device. [Figure 4] FIG. 2 is a plan view of a weighing platform that constitutes the weighing device. [Figure 5] FIG. 2 is a diagram showing an example of a screen of a display unit constituting the weighing device. [Figure 6] 4 is a flowchart showing an example of processing in a foreign object entrapment inspection mode (hereinafter simply referred to as inspection mode) performed by the weighing device. [Figure 7] 10(A) to 10(D) are diagrams showing examples of the screen of the display unit in the inspection mode. [Figure 8] 10(A) to 10(C) are diagrams showing examples of the screen of the display unit in each step of the inspection mode. [Figure 9] FIG. 4 is a diagram illustrating the conditions of a foreign object entrapment detection experiment using the weighing device according to the first embodiment. [Figure 10] 10A and 10B are diagrams showing the results of a foreign object entrapment detection experiment (Experiment 1). [Figure 11] 10A and 10B are diagrams showing the results of a foreign object entrapment detection experiment (Experiment 2). [Figure 12] FIG. 4 is a control block diagram of a weighing device according to a modified example of the weighing device according to the first embodiment. [Figure 13] 10A and 10B are diagrams illustrating an example of an output mode to an operator by the weighing device according to the modified example. [Figure 14] 10A and 10B are diagrams illustrating another example of the manner of output to an operator by the weighing device according to the modified example. [Figure 15]10(A) and 10(B) are diagrams illustrating a plurality of regions set on the weighing platform of a weighing device according to another modified example of the first embodiment. [Figure 16] FIG. 10 is a schematic explanatory diagram of a foreign object inspection system for a weighing device according to a second embodiment. [Figure 17] FIG. 2 is a block diagram of the system. [Figure 18] 10(A) to 10(C) are diagrams showing examples of screens on the display unit of the inspection module that constitutes the system. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. In the embodiments and modifications, common elements are designated by the same reference numerals, and descriptions thereof will be omitted where appropriate. In the following description, directions such as front, back, left, and right refer to directions as seen from the perspective of the person being weighed when the weighing device is in use (i.e., when the person is standing on the weighing device), unless otherwise specified.

[0017] (Mechanical configuration of the weighing device) Fig. 1 is a front perspective view of a weighing device 100 according to an embodiment. Fig. 2 is a rear view of the weighing device 100. The weighing device 100 is a large medical scale known as a barrier-free scale, which is configured so that the weight of the person to be weighed can be measured not only when the person stands on the weighing platform, but also when the person is in a wheelchair. Fig. 3 is a control block diagram of the weighing device 100.

[0018] As shown in FIG. 1, the weighing device 100 mainly includes a weighing platform 20, a handrail 30, and a display 40.

[0019] The weighbridge 20 externally comprises a weighbridge main body 21 on which the load to be weighed is placed, and side bars 22 (left side bar 22L and right side bar 22R) disposed on the left and right sides of the weighbridge main body 21 and extending the length of the weighbridge 20 in the front-to-rear direction. The weighbridge 20 is rectangular in top view and is large enough to allow a person to be weighed to climb onto it either directly or while seated in a wheelchair. The weighbridge main body 21 is also flat and has a structure with sufficient rigidity.

[0020] Slopes 23 are formed as part of the weighbridge main body 21 at both the front and rear ends of the weighbridge main body 21. The slopes 23 become lower as they go outward in the front-to-rear direction, making it easier for the person to be weighed to get on and off the weighbridge main body 21. In addition, anti-slip pads 24 are attached to the slopes 23 to prevent the person to be weighed from slipping when getting on and off the weighbridge main body 21.

[0021] The left and right ends of the weighbridge main body 21 are connected to side bars 22. Each side bar 22 is formed in the shape of a hollow pillar, and stores wiring, electronic boards, etc. therein.

[0022] A handle 25 is attached at a distance from the outer surface of the right side bar 22R. Two wheels 26 (FIG. 2) are attached at a distance from the outer surface of the left side bar 22L. The wheels 26 are rotatable on a horizontal plane when installed as shown. The weighing platform 20 is tilted so that the right side bar 22R is on the upper side and the left side bar 22L is on the lower side, and with the wheels 26 in the ground, the weighing device 100 can be freely moved by holding the handle 25 and moving the weighing platform 20.

[0023] Handrails 30 are attached to the top surfaces of the side bars 22 along the front-to-rear direction. The handrails 30 have a generally inverted U-shape that opens downward, and are erected at two locations spaced apart in the front-to-rear direction of the side bars 22 so that their upper edges are parallel to the side bars 22. This allows the person to be weighed to hold onto the handrails 30 and safely get on and off the weighing platform main body 21.

[0024] A pole 45 is detachably and rotatably attached to the front of the front standing portion 31 of the handrail 30 on the upper surface of the right side bar 22R. The pole 45 stands perpendicular to the right side bar 22R, then curves and extends parallel to the weighbridge main body 21, with a display 40 attached to its tip. Therefore, the position of the display 40 can be adjusted by rotating the pole 45.

[0025] In addition, four different marks (first to fourth marks M1 to M4) are attached to the upper surfaces of the left and right side bars 22L, 22R near the front upright portion 31 and near the rear upright portion 32 of the handrail 30, i.e., the front and rear of the left side bar 22L and the front and rear of the right side bar 22R.

[0026] As shown in Fig. 2, legs 28 are provided on the underside of the side bars 22. The legs 28 are located at both ends of the left and right side bars 22L, 22R, i.e., at the four corners (front left, rear left, front right, rear right) of the weighbridge 20. First to fourth weighing sensors 51a to 51d are provided between each leg 28 and the side bar 22, respectively. In other words, the weighbridge main body 21 is supported by the legs 28 via the first to fourth weighing sensors 51a to 51d.

[0027] Unless otherwise specified, the first weighing sensor 51a provided at the front (left front) of the left side bar 22L, the second weighing sensor 51b provided at the rear (left rear) of the left side bar 22L, the third weighing sensor 51c provided at the front (right front) of the right side bar 22R, and the fourth weighing sensor 51d provided at the rear (right rear) of the right side bar 22R will be collectively referred to as weighing sensors 51.

[0028] The weighing sensor 51 is a sensor that measures the load placed on the weighbridge 20. In the weighing device 100, the weighing sensor 51 is connected to a control and calculation unit 60 (described later) via wiring (not shown).

[0029] The weighing sensor 51 may be, for example, a load cell. Any known load cell, such as a strain gauge type, a piezoelectric element type, or a capacitance type, may be used. The shape of the strain body is not particularly limited, and any known configuration, such as a Roberval type, a column type, or a ring type, may be used. In this example, a strain gauge type Roberval load cell is used. The weighing sensor 51 is specifically configured such that four gauges are attached to four thin-walled portions of the strain body of the Roberval load cell, and these four gauges are connected to form a bridge circuit, and each output value (data that has not been converted into a weighing value or processed) is output to the control and calculation unit 60.

[0030] The display device 40 is a display device that includes a display unit 41 and an input unit 42. The display device 40 also houses a board, a power supply 43, a memory unit 44, and the like that constitute the control and calculation unit 60 shown in FIG.

[0031] The display unit 41 is, for example, a liquid crystal display, an organic EL display, etc. The display unit 41 displays setting conditions, measurement values, an instruction image for foreign object inspection (described later), and an image of the foreign object detection result under the control of the control calculation unit.

[0032] The input unit 42 is, for example, a key switch, and includes a power switch and other operation switches. Various settings and instructions for the weighing device 100, such as "tare weight," "output of weighing value," and "zero point (reset)," can be input from the operation switches. The operation switches also include an inspection switch (not shown) for switching from normal weighing mode to inspection mode. The display unit 41 and the input unit 42 may be configured integrally and provided as a touch panel type input unit 42.

[0033] The storage unit 44 is at least one computer-readable storage medium, such as a hard disk drive (HDD), flash memory, etc. The storage unit 44 stores programs for the weighing device 100 to execute the normal measurement mode, the inspection mode, and other functions. The storage unit 44 also stores measurement values.

[0034] The control and calculation unit 60 includes at least one electronic circuit and at least one memory. As the electronic circuit, for example, a processor such as a CPU (Central Processing Unit) is used. As the memory, for example, an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory) is used. When a CPU is used, the control and calculation unit 60 executes various functions of the weighing device 100 by reading into the memory and executing a program for the CPU to execute the functions.

[0035] Note that the control and calculation unit 60 may be partially configured as hardware using a CPLD (Complex Programmable Logic Device), an FPGA (Field Programmable Gate Array), etc. In other words, the control and calculation unit 60 may include a processor that realizes functions in software and a processing circuit that realizes functions in hardware.

[0036] 3, the first to fourth weighing sensors 51a to 51d are connected to the first to fourth amplifiers 52a to 52d, respectively, and are connected to the control calculation unit 60 via the first to fourth amplifiers 52a to 52d, respectively. The first to fourth weighing sensors 51a to 51d output individual output values ​​W1 to W4, which are amplified by the corresponding first to fourth amplifiers 52a to 52d, respectively, and input to the control calculation unit 60.

[0037] The control and calculation unit 60 calculates the weight value M using the sum of the input output values ​​of the first to fourth weighing sensors 51a to 51d. The control and calculation unit 60 also displays the calculated weight value M on the display unit 41. In the normal measurement mode, the control and calculation unit 60 executes zero point setting, calculates the weight value based on the output values ​​of the weighing sensors 51 input at any time, determines whether the weight value is stable, and displays the weight value on the display unit 41.

[0038] The control and calculation unit 60 also includes a foreign object detection unit 61 as a functional unit for executing the inspection mode. The foreign object inspection function executed by the foreign object detection unit 61 will be described below.

[0039] (Foreign object inspection function) The foreign object detector 61 sequentially calculates the weight values ​​when the same inspection load is applied to the four corners and the center of the weighbridge 20, and detects a foreign object by determining that a foreign object has been trapped if the difference between the maximum and minimum of the five weight values ​​at the four corners and the center is equal to or greater than a predetermined threshold. The detector also determines that the position corresponding to the minimum value is the position where the foreign object is trapped.

[0040] This is because when the inspection load is placed on the weighbridge 20, the weighbridge 20 sinks downward, and if a foreign object is present between the weighbridge 20 and the installation surface, the foreign object will come into contact with the weighbridge 20 and interfere, resulting in a calculated weighing value that is smaller than the actual value. Also, it is because the impact on the weighing value is greatest at the position where the foreign object is trapped.

[0041] For this reason, four areas are set on the weighbridge 20, corresponding to the four corners of the weighbridge 20. FIG. 4 is a plan view of the weighbridge 20. For ease of explanation, however, the figure shows the state in which the handrail 30, the display 40, and the pole 45 have been removed. The holes provided on the top surface of the right side bar 22R are the mounting hole 27a for the handrail 30 and the mounting hole 27b for the pole 45. The hole provided on the top surface of the left side bar 22L is the mounting hole 27a for the handrail 30.

[0042] The first to fourth regions LF, LR, RF, and RR corresponding to the four corners are defined in a top view by a line segment l that passes through the center O of the weighbridge 20 and extends in the front-to-rear direction, and a line segment m that passes through the center O and extends in the left-to-right direction and is perpendicular to the line segment l. In the illustrated example, the line segments l and m are imaginary lines (dotted lines), but they may also be actually drawn on the weighbridge 20.

[0043] The first to fourth areas LF, LR, RF, and RR corresponding to the four corners are marked with different first to fourth marks M1 to M4, respectively. Specifically, a first mark M1 (circle) is marked on the front of the left side bar 22L, a second mark M2 (triangle) is marked on the rear of the left side bar 22L, a third mark M3 (square) is marked on the front of the right side bar 22R, and a fourth mark M4 (star) is marked on the rear of the left side bar. The marks may be marked on the top surface of the weighbridge main body 21 instead of on the side bar 22. However, since the marks are used not during normal weighing but during inspection, it is preferable to mark the marks on the side bar 22 because they are less noticeable to the person being weighed, yet the corresponding areas can be clearly identified during inspection mode operation.

[0044] The foreign object detection unit 61 displays the first to fourth marks M1 to M4 on the display unit 41 to instruct the worker on the position where the inspection load should be applied, and weighs the inspection load applied in accordance with the instructions.

[0045] 5 shows an example of a screen displayed on the display unit 41. The display unit 41 has a measurement value display area 41a and a foreign object inspection display area 41b. The measurement value display area 41a displays the measurement value M calculated by the control and calculation unit 60 in the normal measurement mode and the inspection mode.

[0046] In the foreign object inspection display area 41b, a schematic diagram 70 of the weighbridge 20, modeled after a top view thereof, is displayed with the top of the display unit 41 facing forward. The schematic diagram 70 of the weighbridge 20 is divided into areas corresponding to the four corners, just like the actual weighbridge 20. A first mark image 71a, a second mark image 71b, a third mark image 71c, and a fourth mark image 71d are displayed at positions corresponding to the left front, left rear, right front, and right rear areas, respectively, which indicate the same marks as the first mark M1, second mark M2, third mark M3, and fourth mark M4 that are affixed to the corresponding areas of the actual weighbridge 20.

[0047] The foreign object detection unit 61 instructs the worker on the loading position of the inspection load by displaying a first mark image 71a, a second mark image 71b, a third mark image 71c, and a fourth mark image 71d on a schematic diagram 70 of the weighbridge displayed on the display unit 41.

[0048] In addition, the foreign object detection unit 61 calculates five measurement values ​​measured by placing an inspection load on the center and each of the first to fourth regions LF, LR, RF, and RR, compares the difference between the maximum and minimum of the five measurement values ​​with a predetermined threshold value, determines whether a foreign object has been pinched, and displays the determination result on the display unit 41.

[0049] Furthermore, the foreign object detection unit 61 determines that the position corresponding to the smallest value of the five measured values ​​is the foreign object pinch position, and displays the determination result in the foreign object inspection display area 41b of the display unit 41, as will be described later. At this time, a foreign object detection position display 72 is displayed in the foreign object inspection display area 41b.

[0050] (Foreign object detection mode operation) Next, the operation of the weighing device 100 in the inspection mode will be described with reference to Figures 6 to 8. Figure 6 is a flowchart of the processing in the inspection mode of the weighing device 100. Figures 7(A) to (D) and Figures 8(A) to (C) show examples of screens displayed on the display unit 41 during this processing.

[0051] 7(A)-(D) and 8(A)-(C) are the same screens of the display unit 41 of the weighing device 100 as in FIG. 5, but are drawn in reversed black and white. The reversed black and white is a matter of convenience, and either is acceptable. The illustrated examples are merely illustrative, and can be changed as appropriate, including the colors. However, the first to fourth mark images 71a-71d may be displayed in different colors as long as they are the same as the first to fourth marks M1-M4 affixed to the weighing platform 20, but it is preferable to use the same or similar colors to make them easier to recognize.

[0052] When the weighing device 100 is turned on, it operates in normal measurement mode. In normal measurement mode, the weighing sensor 51 detects the load placed on the weighbridge 20 at predetermined intervals, and the control and calculation unit 60 executes the basic operation of determining stability when a load is placed on the weighbridge 20, calculating a weighing value, and displaying the weighing value on the display unit 41.

[0053] When operating in the normal measurement mode, the inspection switch is monitored for depression, and when the inspection switch is depressed (Yes) in step S01, the inspection mode begins. Next, in step S02, the foreign object detection unit 61 displays "__._kg" in the measurement value display area 41a on the display unit 41 as an initial display of the inspection mode.

[0054] At the same time, in step S03, the foreign object detection unit 61 executes zero point setting. That is, the inspection switch in step S01 functions as a zero set key. When the zero point is set (Yes), in step S05, the foreign object detection unit 61 sets the counter to n=1.

[0055] The counter is set to correspond to the loading position of the inspection load, where n is a natural number between 1 and 5, and is predefined such that n=1 is the center, n=2 is the left front, n=3 is the left rear, n=4 is the right front, and n=5 is the right rear. Therefore, when n=1, the loading position is set to the center.

[0056] Next, in step S06, "XXX.XXg" is displayed in the measurement value display area, and an instruction for the loading position is displayed in the foreign object inspection display area 41b. Here, since the loading position is the center, the foreign object detection unit 61 displays all of the first to fourth marks in the center of the drawing, as shown in FIG. 7(A).

[0057] In response to this instruction, the worker places the inspection load on the center of the weighbridge 20. The inspection load may be a weight, a plastic bottle filled with water, or the worker himself or herself.

[0058] Next, in step S07, the foreign object detection unit 61 determines whether the weight value has stabilized. If it is determined to be stable (Yes), in step S08, the foreign object detection unit 61 determines whether the weight value is 5 kg or more. If it is 5 kg or more (Yes), in step S09, the weight value is stored in the memory unit 44. Note that the determination of whether it is 5 kg or more is made in order to determine whether the inspection load has been reliably applied.

[0059] On the other hand, if stability is not determined in step S07 (No), the process returns to step S06 and repeats the process until stability is determined in step S07. Similarly, if the weighed value is not 5 kg or more in step S08 (No), the process also returns to step S06 and waits while repeating the process until the weighed value is 5 kg or more in step S08.

[0060] Following step S09, in step S10, the foreign object detection unit 61 determines whether the counter count is 5 or more, i.e., whether inspection weights have been measured for all of the center, left front, left rear, right front, and right rear. If the counter count is n=1 (No), in step S11 the foreign object detection unit increments the counter to n=n+1 (n=2). Then, steps S06 to S10 are repeated.

[0061] Specifically, when the counter is n=2, as shown in FIG. 7(B), a first mark image 71a corresponding to the first mark M1 placed in the front left area LF of the weighbridge 20 is displayed on the schematic diagram 70 of the display unit 41, instructing the worker to place the load on the front right position of the work platform. Following the instructions on the screen, the worker places the inspection load on the front left area LF on the weighbridge 20, using the first mark M1 placed on the left side bar 22L as a landmark. Then, as in the case of n=1, the worker weighs the load at the front left position, and stores this in the memory unit 44 as the weigh value when loaded on the front left.

[0062] Then, in step S10, steps S06 to S10 are repeated until the count reaches 5, that is, until the weighing values ​​for all of the center, left front, left rear, right front, and right rear positions have been stored. The same inspection load is used at this time. Figures 7(C), 7(D), and 8(A) show screens displayed on display unit 41 in step S06 when the counter is n=3, n=4, and n=5, respectively. Then, when the weighing values ​​for all positions have been stored, the process proceeds to step S12.

[0063] In step S12, the foreign matter detector 61 rearranges the five measured values ​​obtained in steps S06 to S10 in ascending order.

[0064] Next, in step S13, the foreign object detection unit 61 determines whether the difference between the maximum and minimum of the five weighing values ​​is equal to or greater than a predetermined threshold. The threshold is set based on the operating tolerance and inspection load specified for the weighing device 100's accuracy, such as twice the scale interval. This is because the Measurement Act stipulates that the operating tolerance for Class 3 accuracy, which is the classification for mainstream weighing scales, is the scale interval up to 500 scale intervals, twice the scale interval for scales between 500 and 2000 scale intervals, and three times the scale interval for scales between 2000 and 10,000 scale intervals. This allows the detection of a foreign object to be determined without including erroneous detection due to errors in the weighing sensor itself. If the difference between the maximum and minimum weighing values ​​is less than the threshold (No), the foreign object detection unit 61 determines that no foreign object is trapped, and in step S14, an OK message 73 is displayed on the display unit 41, as shown in FIG. 8(B), for example.

[0065] If the inspection switch is pressed in step S15 while the OK message is displayed (Yes), the weighing device 100 ends the inspection mode process and returns to operation in the normal measurement mode.

[0066] If the difference between the maximum and minimum measured values ​​is equal to or greater than the threshold in step S13, the foreign object detection unit 61 determines the position corresponding to the minimum value in step S16. If the position corresponding to the minimum value is the center, the foreign object detection unit 61 determines in step S17 that a foreign object is present in the center. Similarly, if the position corresponding to the minimum value is the front left, the foreign object detection unit 61 determines in step S18 that a foreign object is present in the front left. Similarly, if the positions corresponding to the minimum value are the rear left, front right, or rear right, the foreign object detection unit 61 determines in steps S19 to S21 that a foreign object is present at each of these positions.

[0067] Next, in step S22, depending on the determination results of steps S17 to S21, an NG indicator 74 indicating that a foreign object has been detected and a foreign object detection position indicator 72 indicating the location of the foreign object are displayed on the display screen. Fig. 8(C) shows an example of the display screen when it is determined that a foreign object is present in the rear left. As shown in Fig. 8(C), the foreign object detection position indicator displays the foreign object detection position in foreign object inspection display area 41b on a schematic diagram 70 of the weighing platform, along with a mark image corresponding to the foreign object detection position (if it is in the center, all mark images are displayed).

[0068] When the inspection switch is pressed in step S23, the foreign matter detection unit ends the process and returns to the normal measurement mode.

[0069] If a foreign object is detected to be trapped, the operator turns off the power, searches under the position where the abnormality was detected, either while the weighing device is installed or by lifting it up, and removes the foreign object before using the weighing device 100.

[0070] As described above, the weighing device 100 according to this embodiment is configured to set the areas where the inspection load is to be placed, corresponding to the center and the four corners, instruct the operator on the location where the inspection load should be placed, weigh the same inspection load at each location, and determine that a foreign object has been trapped if the difference between the maximum and minimum measured values ​​at each location is equal to or exceeds a predetermined threshold. This allows even an unfamiliar operator to easily inspect for trapped foreign objects by simply placing the inspection load at the designated location according to the instructions from the weighing device 100. Furthermore, the inspection load can be not only a weight with a known mass, but also an unknown weight, such as a plastic bottle filled with water or the operator himself, making inspection possible even without a large weight such as 20 kg.

[0071] Furthermore, if the worker (person) gets on and off the weighing platform as the inspection load, he or she can check for trapped foreign objects without having to put on or take off heavy weights or plastic bottles, which significantly reduces the workload. Furthermore, because the workload is reduced, the psychological barrier to checking for trapped foreign objects is reduced, and the risk of the weighing device 100 being used without inspection is reduced.

[0072] Furthermore, if the worker himself is used as the inspection load, a load of about 65 kg can be applied, which is the average weight of a Japanese adult, making it possible to inspect with a larger load than when using weights. Measurement errors due to the entrapment of foreign objects occur when the weighing platform 20, which sinks downward due to the applied load, comes into contact with the foreign object. If the worker himself is used as the inspection load, a larger load than a weight can be applied, making it possible to detect even the slightest entrapment of foreign objects that cannot be detected with a weight.

[0073] On the other hand, when the inspection mode is executed using a weight with a known mass, the inspection result can be double-checked by comparing the nominal value of the weight with the measurement value M displayed on the display unit 41 during the inspection mode, thereby making it possible to confirm whether the foreign object inspection was carried out properly.

[0074] Furthermore, the weighing device 100 is configured to determine that a foreign object is trapped at the position showing the minimum value and to notify the user of that position. With this configuration, the location of the foreign object can be determined without lifting the weighing device 100, making it easy to search for the foreign object. Even when lifting the weighing device 100, the location of the foreign object can be searched for with a minimum number of attempts, reducing the workload.

[0075] Furthermore, in the weighing device 100 according to this embodiment, unique first to fourth marks M1 to M4 are affixed to the center and areas corresponding to the four corners of the weighbridge 20. The display unit 41 is configured to display a schematic diagram 70 of the weighbridge, and to display first to fourth mark images 71a to 71d at positions corresponding to the first to fourth marks M1 to M4 affixed to the weighbridge 20. The operator is then instructed on the placement position of the inspection load by displaying marks at positions corresponding to the marks affixed to the areas where the inspection load is to be placed.

[0076] With this configuration, the worker can visually recognize the mark image in the schematic diagram 70 of the weighbridge and place the inspection load at the position indicated by the mark image without making a mistake. Furthermore, since a corresponding mark is also attached to the weighbridge 20, the worker can confirm the mark attached to the weighbridge 20 and understand the correct position. As will be shown in a modified example described later, instructions to the worker and output of the inspection results may be given not only by display on the display unit but also by voice or the like. However, in this embodiment, the loading position is displayed schematically on the display unit 41, which makes it possible to understand the loading position more intuitively.

[0077] (experiment) Next, it was confirmed through an experiment that the weighing device 100 can detect the presence of a foreign object.

[0078] Experimental Method In the experiment, as shown in FIG. 9(A), a door stopper 90 was assumed to be a foreign object wedged between the bottom of the weighing platform and the installation surface (floor surface FL) to the extent that the weighing value did not change when the zero point stabilized in the inspection mode of the weighing device 100. The foreign object was wedged at nine positions indicated by arrows (1) to (8) and (9) in FIG. 9(B), namely, the positions of the first to fourth marks M1 to M4, the intermediate position between two adjacent marks M1 to M4 (for example, the intermediate position between the first mark M1 and the second mark M2 is position (2)), and below the center O. With the foreign object wedged at each position, the inspection mode was performed, and the worker (an adult weighing 66.3 kg) stepped on and off the weighing platform 20 as the inspection load.

[0079] result As shown in Figure 10, foreign objects were detected at all pinch positions, resulting in an "NG" result. Furthermore, when foreign objects were pinched at the positions of the first through fourth marks M1 through M4 ((1), (3), (5), (7)) and the central position (9), it was determined that foreign objects were pinched at the positions corresponding to the marks. Furthermore, when foreign objects were pinched at the intermediate positions ((2), (4), (6), (8)) between two adjacent marks among the first through fourth marks M1 through M4, it was determined that foreign objects were pinched at the positions corresponding to the marks on the same side.

[0080] In this way, it was confirmed that the weighing device 100 according to this embodiment can accurately detect the presence of a foreign object.

[0081] (Experiment 2) Experimental Method In Experiment 2, the door stopper 90 was sandwiched between the bottom of the weighing platform 20 and the installation surface (floor surface FL) at positions (1), (3), (5), and (7) in Figure 9(B) so that a 20 kg weight placed in the center could be weighed correctly. The inspection mode was performed using a 20 kg weight as the inspection load and when the worker (a human (adult) weighing 66.0 g) got on and off the weighing platform.

[0082] result As shown in FIG. 11, when the worker himself got on and off the car, as in Experiment 1, the pinching of a foreign object was detected (NG) at all pinching positions, and the pinching positions were correctly determined.

[0083] In this way, it was confirmed that by using the workpiece itself (a human) as the inspection load, it is possible to detect slight pinching that cannot be detected with a 20 kg weight.

[0084] (Variation) Variation 1 Next, modifications of this embodiment will be described. Fig. 12 is a control block diagram of a weighing device 100A according to Modification 1. Figs. 13(A) and 14(A) are diagrams illustrating how the weighing device 100A outputs instructions to an operator. Figs. 13(B) and 14(B) are diagrams illustrating how the weighing device 100A outputs the results of a foreign object inspection to an operator. The weighing device 100A has roughly the same mechanical configuration as the weighing device 100, but differs in the following respects.

[0085] The weighing device 100 further includes an audio output unit 46. The audio output unit 46 is a speaker and is housed in the display 40A. The audio output unit 46 outputs the output content to the operator by voice in accordance with instructions from the control and calculation unit 60A.

[0086] For this reason, in the processing of step S06 in the inspection mode, the foreign object detection unit 61A of the control calculation unit 60A is configured to instruct the worker on the loading position of the inspection load by voice, as shown in Figure 13(A), instead of or in addition to the display on the display unit 41A.

[0087] Furthermore, in the process of step S22 in the inspection mode, foreign object detection unit 61A is configured to output the inspection result to the operator by voice, as shown in Fig. 13(B), instead of or in addition to displaying it on display unit 41A. The same applies to step S14.

[0088] When outputting instructions and results by voice, if a word directly indicating a position, such as center or left front, is used, the first to fourth marks M1 to M4 do not necessarily need to be attached to the left and right side bars 22AL, 22AR of the weighbridge 20A. In this case, the load position instructions and entrapment position displayed on the display unit 41 do not use mark images, but rather words directly indicating the position. Even with such modifications, it is possible to achieve the same effect as the weighing device 100 according to the embodiment, that is, even an unfamiliar worker can easily inspect for entrapped objects. Furthermore, the inspection load can be not only a weight with a known mass, but also an object with an unknown weight, such as a plastic bottle filled with water or the worker himself, thereby achieving the same effect as the weighing device 100, that is, inspection can be performed even without a large weight such as 20 kg.

[0089] 14(A) and 14(B), first to fourth marks M1 to M4 may be attached to the left and right side bars 22L, 22R as in the embodiment, and instructions on the loading position and the clamping position may be output by voice using expressions representing the first to fourth marks M1 to M4. In this way, it is possible to achieve the same effect as the weighing device 100, in that the worker can confirm the marks attached to the weighbridge 20 and understand the correct position.

[0090] Thus, in the weighing device 100, the display unit 41 functions as an output unit in the claims, and in the weighing device 100A, the audio output unit 46 functions as an output unit in the claims. However, the output of the inspection results is not limited to display on the display unit 41 or audio output by the audio output unit 46, and may be performed in other ways. Specifically, the display unit 40 may be equipped with a printer controlled by the control and calculation unit 60, and the results may be output via printer output. Also, the display unit 40 may be equipped with a communication unit, and the results may be output via communication to an external device such as a personal computer or smartphone. In this case, the communication unit may be a communication device such as a network interface card (NIC) that enables wired or wireless communication with external devices. Furthermore, these output modes may be used in combination.

[0091] (Variations 2 and 3) The number of regions set on the weighbridge 20 may be modified as in the following Modifications 2 and 3. Figures 15(A) and 15(B) are diagrams illustrating the multiple regions set on the weighbridges 20B and 20C of the weighing devices 100B and 100C according to Modifications 2 and 3, respectively. The weighing devices 100B and 100C have the same mechanical configuration as the weighing device 100, except for the number of regions set.

[0092] As shown in FIG. 15(A), two regions are defined on weighbridge 20B by line segment 1 that passes through center O and extends in the front-to-rear direction. Furthermore, as shown in FIG. 15(B), eight regions are defined on weighbridge 20C by line segment l that passes through center O and extends in the front-to-rear direction, and line segments l1, l2, and l3 that also pass through center O. Thus, the number of regions is not limited to four, corresponding to the four corners, but may be any number of regions defined by at least one line segment. In this case, whether the inspection load has been measured in all of the regions and at all positions in the center in step S10 can be determined by determining whether the counter is equal to or greater than the number of regions set + 1.

[0093] If the number of partitioned areas is large, the number of times the inspection load needs to be weighed increases, but the accuracy of detecting the position of a trapped foreign object improves.If the number of partitioned areas is small, the number of times the inspection load needs to be weighed decreases, and the time required for inspection is shortened.

[0094] (Second embodiment) 16 is a schematic view of the appearance of a foreign matter inspection system (hereinafter simply referred to as the system) 200 for a weighing device according to a second embodiment of the present invention. FIG.

[0095] The system 200 includes a weighing device 100D and an inspection module 80. The weighing device 100D is a conventional weighing device without a foreign object inspection function. The weighing device 100D has the same configuration as the weighing device 100, except for the following points. In addition to the weighing device 100, the weighing device 100D also includes a communication unit 47, which allows it to send and receive information with external devices. The control and calculation unit 60D does not include a foreign object detection unit 61. The control and calculation unit 60D transmits the weight value to the inspection module in accordance with instructions from the inspection module 80. The control and calculation unit 60D also performs zero point setting in accordance with instructions from the inspection module 80. In the illustrated example, first to fourth marks M1 to M4 are attached to correspond to the multiple set regions LF, LR, RF, and RR. As explained in Variation 1, these marks may not be required depending on the manner in which the inspection load application position is specified and the foreign object inspection results are output. However, in the illustrated example, because they are necessary for indicating the loading position and outputting the foreign object inspection results, they are attached to the left and right side bars 22L, 22R as stickers, etc. For this reason, multiple marks corresponding to multiple set areas may be included as part of the system as stickers, etc., and may be attached to the side bars 22 for use.

[0096] The communication unit 47 enables wireless or wired communication with the inspection module 80. A communication device such as a NIC can be used as the communication unit 47. Alternatively, short-range communication technology such as Bluetooth (registered trademark) or infrared communication may be used.

[0097] The display unit 41D does not include the foreign substance inspection display area 41b, but only includes the measurement value display area 41a.

[0098] The control calculation unit 60D transmits and receives information to and from the inspection module 80 via the communication unit 47. When the control calculation unit 60 receives an instruction to start the inspection mode from the inspection module 80, it starts transmitting measurement values ​​to the inspection module 80, and transmits the measurement values ​​at any time while the inspection mode is being executed.

[0099] The inspection module 80 includes a display unit 81 , an input unit 82 , a storage unit 83 , a communication unit 84 , and a module calculation unit 85 .

[0100] The display unit 81 is, for example, a liquid crystal display, an organic EL display, etc. An instruction image for inspecting for foreign matter and an image of the foreign matter detection result are displayed on the display unit 81 under the control of the module calculation unit 85.

[0101] The input unit 82 is, for example, a key switch, and includes a power switch 82a and an inspection switch 82b. Other operation switches may also be provided. The display unit 81 and the input unit 82 may be integrated into one unit to provide a touch panel type input unit 82.

[0102] The storage unit 83 is at least one computer-readable storage medium, such as a hard disk drive (HDD), a flash memory, etc. The storage unit 83 stores a program for the system 200 to execute the inspection mode. The storage unit 83 also stores measurement values.

[0103] The same communication device as the communication unit 47 of the weighing device 100D is adopted for the communication unit 84. Via the communication unit 84, the module calculation unit 85 can send and receive information to and from the control calculation unit 60D of the weighing device 100D.

[0104] The module computing unit 85 includes at least one electronic circuit and at least one memory. As the electronic circuit, a processor such as a CPU is used, for example. As the memory, an SRAM, a DRAM, or the like is used. When a CPU is used, the module computing unit 85 executes the inspection mode by reading a program stored in the storage unit 83 into the memory and executing the program for the CPU to execute its functions.

[0105] Note that the module calculation unit 85 may be partially configured as hardware using a CPLD, FPGA, etc. That is, the module calculation unit 85 may include a processor that realizes functions in software and a processing circuit that realizes functions in hardware.

[0106] The module calculation unit 85 includes a foreign object detection unit 86 equivalent to the foreign object detection unit 61. The foreign object detection unit 86 executes a foreign object inspection mode and displays the inspection results on the display unit 81. The display unit 81 displays a display equivalent to the foreign object inspection display area 41b of the display unit 41 of the weighing device 100, that is, it displays instructions to the operator and the inspection results using the schematic diagram 70 of the weighing platform. An example of the display on the display unit 81 is shown in FIG. 18.

[0107] The processing performed by foreign object detection unit 86 when executing the inspection mode is generally the same as the flowchart in Figure 6, except that the processing by foreign object detection unit 86 is executed by the inspection module, the measurement values ​​are sent to inspection module 80 via communication units 47 and 84, and instructions to the operator on where to place the inspection load and a display of the foreign object inspection results are displayed on display unit 81 of inspection module 80. The differences will be briefly explained below.

[0108] In step S01, when the inspection switch 82b is pressed, the module calculation unit 85 transmits information that the inspection switch 82b has been pressed to the weighing device 100D. The weighing device 100D starts transmitting the measurement value to the inspection module 80. In step S06, instructions for the loading position are displayed on the display unit 81 of the inspection module 80. Figure 18(A) shows a display instructing loading on the center, and Figure 18(B) shows a display instructing loading on the left front area. In addition, in step S22, the foreign object detection results (that a foreign object has been detected and the location where the foreign object was detected) are displayed on the display unit 81 of the inspection module 80. Figure 18(C) shows the display of the foreign object detection results.

[0109] In this way, by using the inspection module 80, the system 200 can achieve the same effect as the weighing device 100 even when using a conventional weighing device 100D that does not have a foreign object inspection function.

[0110] Although the preferred embodiments and modifications of the present invention have been described above, these may be modified and combined based on the knowledge of those skilled in the art. Specifically, the modifications described for the first embodiment may be combined with the second embodiment. Furthermore, multiple modifications may be combined and applied. [Explanation of symbols]

[0111] 100,100A,100B,100C:Measuring device 200: Foreign object inspection system for weighing equipment 20,20A,20B,20C: Weighing platform 41,41A,81: Display section (output section) 46: Audio output unit (output unit) 51: Weighing sensor 60, 60A: Control calculation section 70: Schematic diagram of weighbridge 71a, 71b, 71c, 71d: First to fourth mark images (mark images) M1, M2, M3, M4: 1st to 4th marks LF, LR, RF, RR: 1st to 4th areas (areas) l, l1, l2, l3: line segments m : line segment

Claims

1. a weighbridge on which an inspection load is loaded; a weighing sensor for detecting a load placed on the weighbridge; a control and calculation unit that calculates a measurement value based on the output value of the measurement sensor; an output unit that outputs the measurement value; Equipped with The control calculation unit A plurality of areas are set on the weighbridge, each area being partitioned by at least one line segment passing through the center of the weighbridge; instructing an operator to sequentially apply the inspection load to each of the plurality of regions and the central portion using the output unit; Weighing the inspection load applied to each of the plurality of regions and each position of the center; a difference between a maximum value and a minimum value of the measured values ​​in the plurality of regions and the central portion is compared with a predetermined threshold value to determine whether a foreign object is trapped; The weighing device is configured to output the result of the determination.

2. 2. The weighing device according to claim 1, wherein, when it is determined in the determination that a foreign object is trapped, it is determined that the position of the trapped foreign object is in a position corresponding to the region showing the minimum value.

3. the output unit includes a display unit, The plurality of areas of the weighbridge are marked with different marks, The weighing device described in claim 1 or 2, characterized in that the control and calculation unit is configured to instruct the worker on the order in which to place the inspection loads by displaying a schematic diagram of the weighing platform on the display unit and displaying mark images on the schematic diagram corresponding to the positions at which the inspection loads should be placed.

4. the output unit includes a display unit, The plurality of areas set on the weighbridge are marked with different marks, The weighing device according to claim 2, characterized in that the control and calculation unit is configured to output the result of the judgment to the operator by displaying a schematic diagram of the weighing platform on the display unit and displaying a mark image corresponding to the pinch position of the foreign object judged on the schematic diagram.

5. The weighing device according to claim 1 or 2, characterized in that the weighing platform is rectangular and has four areas corresponding to the four corners of the weighing platform, which are divided by two perpendicular straight lines passing through the center of the weighing platform.

6. a weighing device including a weighing platform on which an inspection load is placed, a weighing sensor that detects the load placed on the weighing platform, a control and calculation unit that calculates a measurement value based on an output value of the weighing sensor, and a communication unit; an inspection module including a communication unit capable of transmitting and receiving information to and from the weighing device, a module calculation unit, and an output unit; Equipped with The weighing device transmits the measurement value to the inspection module in accordance with an instruction from the inspection module; The module calculation unit A plurality of areas are set on the weighbridge, each area being partitioned by at least one line segment passing through the center of the weighbridge; instructing an operator to sequentially apply the inspection load to each of the plurality of regions and the center portion using the output unit; Calculating a measurement value of the inspection load applied to each of the plurality of regions and each position of the central portion; a difference between a maximum value and a minimum value of the measured values ​​in the plurality of regions and the central portion is compared with a predetermined threshold value to determine whether a foreign object is trapped; A foreign matter inspection system for a weighing device, configured to output the result of the determination.

7. A method for inspecting a weighing device for foreign object entrapment, the method being executed by a computer and including: a weighing platform on which an inspection load is placed; a weighing sensor that detects the load placed on the weighing platform; a control and calculation unit that calculates a measurement value based on an output value of the weighing sensor; and a communication unit, A step of setting a plurality of areas on the weighbridge, each area being partitioned by at least one line segment passing through the center of the weighbridge; instructing an operator to sequentially apply the inspection load to each of the plurality of regions and the central portion; acquiring a measurement value of the inspection load applied to each of the plurality of regions and the central portion; a step of comparing a difference between a maximum value and a minimum value of the measured values ​​in the plurality of regions and the central portion with a predetermined threshold value to determine whether a foreign object is trapped; outputting a result of the determination; A method for providing

8. A program for causing a computer to execute the method of claim 7.

Images