JP2005114425A - Onboard weighing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an onboard weighing device capable of weighing precisely without being affected by an inclination of a load. <P>SOLUTION: The weighing device comprises: load weighing means 11A-11D for supporting a lower face of the container 15; tiltmeters 12A, 12B for measuring the tilt angles of longitudinal direction and lateral direction; and weight operation means 13 for calculating the load by subtracting the weight of the container 15 from the weight measured by the load measuring means 11A-11D. The weight operation means 13 comprises: an initial data memorization part 18 for memorizing the longitudinal and the lateral tilt angles α<SB>0</SB>, β<SB>0</SB>of the set surface of the weight measuring means 11A-11D obtained by the tiltmeters 12A, 12B at the initial state; and a tilt correction operation part 26 for calculating the load W by correcting the weight W<SB>1</SB>measured by the load measuring means 11A-11D at the loaded time by the equation W=W<SB>1</SB>cosα<SB>0</SB>cosβ<SB>0</SB>/(cosαcosβ), wherein α, β are the longitudinal and lateral inclination angles measured by the tiltmeters 12A, 12B. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an on-vehicle weighing device, and more specifically, accurately measures the weight of a load (collected material) stored in a container (such as a tank or a loading platform) mounted on a vehicle such as a vacuum car or a garbage truck. Is.

  Conventionally, as a means for measuring the weight of a load collected and loaded on a vehicle such as a vacuum car or a garbage truck, a weight meter using a stationary vehicle weight meter or a load cell using an in-vehicle strain gauge as a sensor. Etc. are known.

However, with stationary vehicle weighing scales, it is necessary to get on the weighing scale with the collected material loaded, and there are examples that are used at the time of transporting to the treatment plant for human waste collection and garbage collection work. There is a problem that cannot be measured on the spot at each individual collection point. Further, as shown in FIG. 6, in the case of an on-vehicle scale equipped with a load cell 7 on a vehicle 5, a load W ₁ and a tank loaded on the load cell 7 are placed at a place where the road surface G has an inclination (inclination angle θ). There is a problem that an error occurs with the true load W of 6 and the use is limited to a flat place.
As described above, in a field that requires measurement at a collection place such as collection of human waste / septic tank sludge by a vacuum car and collection of garbage by a garbage collection vehicle, an on-vehicle weighing device that is not affected by the inclination of the road surface is required.

Therefore, as shown in FIG. 7, the liquid transport vehicle 1 disclosed in JP-A-8-4102 includes a pressure sensor 6 for detecting a stored liquid pressure provided near the bottom of the liquid storage tank 5, and a liquid storage tank. Inclination angle detection means 7a and 7b are provided at the front and rear of the upper portion of 5 to measure the liquid volume fluctuation and the net volume corresponding to the liquid level and the vehicle body inclination correction by the static liquid level calculation means and the net volume calculation means. It is carried out.
However, in the case of the above publication, since the measurement is performed using the pressure sensor 6, it is necessary to consider the fluctuation of the liquid level and the like, and the vehicle inclination angle data obtained from the inclination angle detecting means 7a and 7b is used. There is a problem that the tilt correction must be performed by performing quite complicated calculation.
JP-A-8-4102

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an on-vehicle weighing device that can accurately and easily measure the loaded weight of a vehicle without being affected by the inclination of the road surface.

In order to solve the above problems, the present invention provides an in-vehicle weighing device that measures the weight of a load housed in a container mounted on a vehicle.
Load measuring means attached to the vehicle and supporting the container;
An inclinometer that measures the front, back, left and right inclination angles of the installation surface of the load measuring means;
Weight calculating means for calculating the weight of the load by subtracting the weight of the container from the load measured by the load measuring means;
The weight calculation means is
An initial data storage unit for storing front and rear and left and right initial inclination angles α ₀ and β ₀ of the load measuring means obtained from the inclinometer in an initial state before accommodation of the load;
W ₁ is the load measured by the load measuring means when the load is stored, α is the front-rear direction tilt angle measured by the inclinometer, and β is the left-right direction tilt angle measured by the inclinometer,
W = W ₁ · cos α ₀ · cos β ₀ / (cos α · cos β)
There is provided an in-vehicle weighing device including an inclination correction calculating unit that calculates a load W after inclination correction using the following formula.

With the above configuration, the load W ₁ applied to the load measuring means, the tilt angles α and β measured by the inclinometer, and the initial tilt angles α ₀ and β ₀ are substituted into the above simple mathematical formula. Thus, even when the vehicle is stopped on an inclined road surface, the inclination correction can be easily performed, and the true weight of the load can be accurately calculated.

Specifically, assuming that the front-rear direction of the vehicle is the X direction, the left-right direction of the vehicle is the Y direction, and the vertical direction is the Z direction, the initial inclination angle α in the Y direction obtained by the inclinometer in an initial state such as a horizontal state of the vehicle. ₀ and the initial inclination angle β ₀ in the X direction are acquired in advance, and in that case, the load component perpendicular to the plane in which the XY plane is inclined about the Y axis is W · cos α ₀ , and the plane further rotates about the X axis. The load component inclined in the direction becomes W · cos α ₀ · cos β ₀ . In addition, when the inclination angles in the X direction and the Y direction acquired from the inclinometer at the time of collection are α and β, the load component perpendicular to the plane in which the XY plane is inclined about the Y axis is W · cos α, The load component whose plane is further inclined around the X axis is W · cos α · cos β. Therefore, as will be described later, the true load W is calculated by W ₁ · cos α ₀ · cos β ₀ / (cos α · cos β), and inclination correction can be easily performed.
Then, by subtracting the container weight from the total weight value obtained by correcting the inclination of the load acquired by the load measuring means, the load weight of the load as the contents can be obtained.

The initial inclination angles α ₀ and β ₀ are acquired from the inclinometer under the same conditions as the vehicle state in which the load measuring means is subjected to span calibration after being mounted on the vehicle.

For example, when load measurement means such as a load cell is mounted on a vehicle, it is necessary to perform span calibration to correct an error between the output value of the load measurement means and the true load value in the in-vehicle state. Under the same conditions as the vehicle condition at the time of span calibration (or simultaneously with span calibration), the initial inclination angle α ₀ and the horizontal inclination angle β ₀ measured by the inclinometer are used as the initial inclination angles. Since the data is stored in the data storage unit, the vehicle does not necessarily have to be horizontal when acquiring the initial data. In other words, it is not necessary to carefully attach the load measuring means so that it is level when mounted on the vehicle, and even if there is a slight inclination at the time of installation, there is no effect on the weighing accuracy, and the weighing accuracy and installation workability are not affected. Can be improved and maintenance-free. Note that span calibration refers to adjustment so that load data converted from the output value of the load measuring means becomes a correct value without error.

Specifically, with a vehicle placed on a stationary track scale, a known weight is mounted on the vehicle, and span calibration is performed by adjusting the displayed value to this known weight or the net weight measured with this track scale. The initial value of the tilt angle is set during the span calibration. By this procedure, when performing span calibration when checking accuracy after one or several years, the measured value of the inclinometer is the same as the initial state by comparing the angle measured with the inclinometer with the initial inclination angle. It can be easily determined whether or not a normal value is indicated. At this time, the same conditions can be guaranteed by measuring with the vehicle on the truck scale. When the accuracy of the initial tilt angles α ₀ and β ₀ stored in advance and the span calibration value are large at the time of checking the accuracy, the initial tilt angle is determined from the inclinometer simultaneously with the span calibration. It is good to acquire again.

An input means for transmitting a signal for temporarily storing the current total load weight accommodated in the container in the storage unit;
A value obtained by subtracting the total loaded weight before the signal input temporarily stored in the storage unit from the total loaded weight after the signal input by the input means is calculated as the collected weight loaded after the signal input.

  With the above configuration, even when it is necessary to calculate the collection weight for each collection place by going around like human waste collection or garbage collection work, the input means is used when the worker starts collecting at each collection place. By inputting a signal at, it is possible to easily calculate the collected weight, which is an increment after the signal is input.

Weight display means for displaying the weight calculated by the weight calculation means is provided.
That is, the operator can recognize the weight immediately by causing the weight display means to display the total loaded weight or / and the collected weight after the inclination correction calculated by the weight calculating means. Contribute to improving the efficiency of collection work.

As is clear from the above description, according to the present invention, even when the vehicle is stopped on an inclined road surface, it is possible to easily perform the inclination correction only by using the above formula, and the weight of the load can be reduced at a low cost. It is possible to calculate with high accuracy. Further, when initial data is acquired by setting the front-rear direction tilt angle α ₀ and the left-right direction tilt angle β ₀ measured by the inclinometer under the same conditions as the vehicle state at the time of span calibration as the initial tilt angle. Even if there is an inclination, the problem does not arise, and workability and weighing accuracy when the on-vehicle weighing device is attached to the vehicle are improved and maintenance becomes free, so that the device can be handled very easily.

Embodiments of the present invention will be described with reference to the drawings.
The on-vehicle weighing device 10 of the present embodiment is attached to a vehicle 16 such as a sanitary vehicle or a garbage collection vehicle equipped with a tank (container) 15 at the rear of the vehicle body, and the weight of a load (collected material) accommodated in the tank 15. Is to measure.

  As shown in FIGS. 1 to 3, the vehicle weighing device 10 includes first to fourth load cells (load measuring means) 11 </ b> A to 11 </ b> D that are fixed on the frame 16 a at the rear of the vehicle body and that support and fix the lower surface of the tank 15. The first and second inclinometers 12A and 12B attached to the frame 16a so as to be parallel to the installation surfaces of the first to fourth load cells 11A to 11D, the first to fourth load cells 11A to 11D, and the first, The weight calculator 13 is connected to the second inclinometers 12 </ b> A and 12 </ b> B by a cable, and the display controller 14 is connected to the weight calculator 13 by a cable. In addition, 1st, 2nd inclinometer 12A, 12B is installed in the surface parallel to the installation surface of 1st-4th load cell 11A-11D so that the inclination angle of 1st-4th load cell 11A-11D can be measured. All that is required is not limited to the above form. Further, as shown in FIGS. 1 and 2, the longitudinal direction of the vehicle 16 is defined as the X direction, the lateral direction is defined as the Y direction, and the vertical direction is defined as the Z direction.

  The first to fourth load cells 11 </ b> A to 11 </ b> D receive the entire weight of the tank 15 by supporting four points with the upper surface as the installation surface of the tank 15. The first inclinometer 12A measures the inclination angle in the front-rear direction (around the Y axis) of the first to fourth load cells 11A to 11D, and the second inclinometer 12B is the left-right direction of the first to fourth load cells 11A to 11D ( The inclination angle around the X axis is measured. Then, the load signals from the first to fourth load cells 11A to 11D and the tilt signals from the first and second inclinometers 12A and 12B are transmitted to the weight calculating means 13.

  As shown in FIG. 3, the weight calculation means 13 receives load signals (voltage values) from the first to fourth load cells 11A to 11D, calculates a load (Kg), and loads applied to the load cells 11A to 11D. Inclination for calculating the inclination angle in the front-rear direction and the inclination angle in the left-right direction by receiving the inclination signal (voltage value) from the load measuring unit 19 for summing (kg) and the first and second inclinometers 12A, 12B An angle acquisition unit 20, a calculation unit 17 that performs various calculation processes, an initial data storage unit 18 that temporarily stores the weight and initial inclination angle of the tank 15 in an initial state, a storage unit 21 that stores various data, The communication means 22 which performs data communication with the display operation device 14 is provided.

The calculation unit 17 calculates the total load weight of loads loaded in the tank 15 and the load weight collected from a certain point in time, and stops the vehicle 16 on an inclined road surface. An inclination correction calculation unit 26 is provided for correcting the inclination error in this case.
The inclination correction calculation unit 17 represents the total load measured by the first to fourth load cells 11A to 11D as W ₁ , and the inclination angle in the front-rear direction (around the Y axis) measured by the first and second inclinometers 12A as α. The inclination angle in the left-right direction (around the X axis) measured by the second inclinometer 12B is β, the initial inclination angle in the front-rear direction measured by the first inclinometer 12A in the initial state is α ₀ , and the second inclination angle in the initial state is second. When the initial inclination angle in the left-right direction measured by the inclinometer 12B is β ₀ , a program for calculating the load W after inclination correction using the following formula 1 is provided.
[Formula 1]
W = W ₁ · cos α ₀ · cos β ₀ / (cos α · cos β)

  The display / operator 14 is an input means 23 for transmitting a signal for temporarily storing the current total load weight of the load stored in the tank 15 in the storage unit 21 and the increment of the load collected after the signal is input. A collected weight display unit 24 that displays the collected weight and a total weight display unit 25 that displays the total loaded weight in the tank 15 are provided.

Next, the principle of inclination correction will be described with reference to FIGS.
First, in span calibration, when the voltage of the first to fourth load cells 11A to 11D when a known weight Ws is loaded is set to Vs, the span coefficient Ss is determined by Ss = Ws / Vs, and the first to fourth This is done by calculating the weight value W when the voltages of the load cells 11A to 11D are V by W = Ss · V.

In the in-vehicle weighing device 10, it is difficult to create a horizontal condition on the XY plane, and the first to fourth load cells 11A to 11A to 11A when the initial inclination angles α ₀ and β ₀ that are inclinations with respect to the vertical direction Z exist at the time of span calibration. load applied to 11D from becoming a Ws · cosα ₀ · cosβ _0, the voltage of the first to fourth load cell 11A~11D becomes _{Vs 0 = Vs · cosα 0 ·} cosβ 0. Therefore, if the span coefficient S is obtained as it is, S = Ws / Vs _{0 is obtained} , and the true span coefficient Ss needs to be obtained by Ss = S · cos α ₀ · cos β ₀ .

When the load W ₁ is actually measured at the location of the inclination angles α and β at the time of collection, the true weight is obtained from the obtained voltage V and the inclination angles α and β of the first to fourth load cells 11A to 11D. The value W is
W = Ss · V / (cos α · cos β)
= S · V · cosα ₀ · cosβ ₀ / (cosα · cosβ)
= W ₁ · cos α ₀ · cos β ₀ / (cos α · cos β)
That is, it is possible to calculate the correct weight (vertical load) W that has been tilt-corrected by the above-described equation 1. Note that the span coefficient S, voltage value Vs ₀ and inclination angles α ₀ and β ₀ when the span calibration is performed are memorized instead of the true span coefficient Ss so that it can be referred to at the time of inspection or repair. Yes.

Next, the operation of the in-vehicle weighing device 10 will be described with reference to the flowchart of FIG.
First, the in-vehicle weighing device 10 is attached to the vehicle 16 and initial setting is performed before the vehicle 16 is shipped (S1). In the initial setting, span calibration of the first to fourth load cells 11A to 11D is performed in a state where the on-vehicle weighing device 10 is mounted on the vehicle (S2). Here, with span calibration, for example, when a load of 4 t is applied to the vehicle 16 with a load cell rated at 80 mV being 5 t, the output should be 64 mV in terms of calculation, but 64 This means setting a span calibration value that corrects 0.025 mV of error when the output is .025 mV.

Simultaneously with the span calibration, initial inclination angles α ₀ and β ₀ acquired from the first and second inclinometers 12A and 12B are set (S2), and the span calibration value and the initial inclination angles α ₀ and β _{0 are set.} Is stored in the initial data storage unit 18 (S3). Note that span calibration and initial inclination angles α ₀ and β ₀ are preferably set periodically.

Further, the routine shown in FIG. 5 is repeatedly calculated in a state where the power source of the in-vehicle weighing device 10 is ON. Specifically, a load signal from the first to fourth load cell 11A~11D by summing calculating the total load W ₁ together with the (S4), first, second inclinometer 12A, the ramp signal from 12B, the front-rear direction Are obtained (S5).
Then, and as to calculate the correct total load W by performing the inclination correction of the total load W ₁ by the equation 1 (S6).

  Further, when a tank setting command is issued from the input means 23 when the interior of the tank 15 is empty at the time of shipment or / and at the start of work inspection when no load is accommodated (S7), The load on the fourth load cells 11A to 11D is added and the tank weight after the inclination correction described above is calculated and registered in the storage unit 21 (S8). This tank weight can be set at the start of work inspection, etc., so that even if the vehicle user attaches an accessory such as a hose to the tank 15 and changes the weight. It becomes.

  And the load measured by the 1st-4th load cell 11A-11D increases because the vehicle 16 starts a patrol for collection of loads (trash etc.), and accommodates a load in the tank 15. However, the total load weight inside the tank 15 is calculated by subtracting the tank weight registered in the storage unit 21 in advance, and is always displayed on the total load weight display unit 25 (S9).

  Further, when the operator inputs a collection start signal from the input means 23 of the display operation unit 14 for each site (S10), the display value of the collected weight display unit 24 that displays only the weight collected at the site is zero. In addition to resetting, the total load weight at the time before collection is temporarily stored in the storage unit 21 (S12), so the total load weight before collection temporarily stored is subtracted from the total load weight after collection. Thus, the collected weight, which is an increment after the signal is input, is calculated and displayed on the collected weight display unit 24 (S11).

  As is clear from the above description, according to the on-vehicle weighing device 10 of the present invention, the total load weight and increment accommodated in the tank 15 regardless of the location and the road surface condition, despite the simple and low-cost device. It is possible to know the collected weight accurately. For example, when weighing in a road surface state tilted 5 degrees forward and backward and 5 degrees left and right, if the tank 15 is 2000 kg and the collected weight is 200 kg, an error of 17 kg occurs if there is no inclination correction. Accurate weighing without error is possible.

In addition, since the initial inclination angles α ₀ and β ₀ are stored in the initial data storage unit 18 at the same time as the span calibration, there is a great advantage that it is not necessary to take initial data when the vehicle is horizontal. That is, even if an inclination occurs when the first to fourth load cells 11A to 11D are fixed to the frame 16a and the tank 15 of the vehicle body, the span calibration is performed in that state, so there is no influence on the measurement accuracy. There is no need for the operator to pay attention to the mounting angle when assembling to the vehicle body, and the mounting workability can be greatly improved.

  In this embodiment, Equation 1 is used for tilt correction. However, the correction coefficient corresponding to the tilt angle of the front, rear, left and right of the tank 15 is previously mapped (characteristic diagram), and the current tilt at the time of weighing is measured. The correction coefficient corresponding to the angle may be acquired with reference to the map. Further, if the display operation unit 14 is wirelessly connected to the weight calculation means 13, it is preferable because the workability of the operator is improved.

It is a side view of the vehicle carrying the vehicle-mounted weighing | measuring apparatus of embodiment of this invention. It is a top view of the vehicle carrying an in-vehicle weighing device. It is a block diagram of a vehicle-mounted weighing device. (A)-(C) are explanatory drawings which show the principle of inclination correction. It is a flowchart explaining the process of a vehicle-mounted weighing apparatus. It is drawing which shows a prior art example. It is drawing which shows another prior art example.

Explanation of symbols

10 On-vehicle weighing devices 11A to 11D First to fourth load cells (load measuring means)
12A, 12B First and second inclinometers
13 Weight calculator 14 Display / operator 15 Tank (container)
16 Vehicle 16a Frame 17 Calculation unit 18 Initial data storage unit 19 Load measurement unit 20 Inclination angle acquisition unit 21 Storage unit 22 Communication unit 23 Input unit 24 Collected weight display unit 25 Total load weight display unit 26 Inclination correction calculation unit

Claims (4)

In the on-vehicle weighing device that measures the weight of the load stored in the container mounted on the vehicle,
Load measuring means attached to the vehicle and supporting the container;
An inclinometer that measures the front, back, left and right inclination angles of the installation surface of the load measuring means;
Weight calculating means for calculating the weight of the load by subtracting the weight of the container from the load measured by the load measuring means,
The weight calculation means is
An initial data storage unit for storing front and rear and left and right initial inclination angles α ₀ and β ₀ of the load measuring means obtained from the inclinometer in an initial state before accommodation of the load;
W ₁ is the load measured by the load measuring means when the load is stored, α is the front-rear direction tilt angle measured by the inclinometer, and β is the left-right direction tilt angle measured by the inclinometer,
W = W ₁ · cos α ₀ · cos β ₀ / (cos α · cos β)
An in-vehicle weighing device comprising: an inclination correction calculating unit that calculates a load W after inclination correction using the mathematical formula. The in-vehicle weighing device according to claim 1, wherein the initial inclination angles α ₀ and β ₀ are acquired from the inclinometer under the same conditions as a vehicle state in which the load measuring means is subjected to span calibration after being mounted on the vehicle. An input means for transmitting a signal for temporarily storing the current total load weight accommodated in the container in the storage unit;
The value obtained by subtracting the total load weight before the signal input temporarily stored in the storage unit from the total load weight after the signal input by the input means is calculated as the collected weight loaded after the signal input. The vehicle-mounted weighing device according to Item 2.   The in-vehicle weighing device according to any one of claims 1 to 3, further comprising weight display means for displaying a weight calculated by the weight calculation means.

Images