JPS593324A - Electronic balance - Google Patents

Abstract

PURPOSE:To improve responsiveness by displaying the average value with little data until the time when the display which is detected beforehand automatically stabilizes, thereafter displaying the average value obtd. by increasing the number of data. CONSTITUTION:The data which is sampled at every prescribed time inteval is averaged by the latest prescribed number, and when the average value thereof attains a prescribed value or above, a calibration mode is started automatically. The time required since the point of the time when the load is removed until the point of the time when the average value attains 0 continuously prescribed times is detected and is taken into the balance in the calibration mode. The average value is displayed momentarily with the little averaged number until said time elapses and when the above-mentioned time elapses, the number of the data for the purpose of averaging is successively increased and the average value is calculated and displayed.

Description

[Detailed description of the invention] The present invention relates to electronic scales.

In general, the display of highly sensitive electronic scales fluctuates greatly due to temporary disturbances such as minute vibrations.
The display method used is to average a large number of data sampled at predetermined time intervals and display the resulting value in order to suppress the above-mentioned fluctuations. However, this method has the disadvantage that the response to the load value actually placed on the electronic scale is extremely slow, which is a problem especially in operations such as weighing a fixed amount.

The present invention has been made in view of the above, and includes a mode that can automatically detect in advance the time from when the load softens until the display becomes stable, and the time period from when the load softens to when the display becomes stable is gradually reduced. To provide an electronic scale capable of improving responsiveness by displaying an average value based on data, and displaying an average value obtained by increasing the number of data when a certain time is reached.

The feature of the present invention is that data sampled at predetermined time intervals is averaged by the latest predetermined number of data for each sampling, and when the average value exceeds a predetermined value set near full scale, the data is automatically In the calibration mode, the removal of the load is detected, and the average value is set to 0 for a predetermined number of consecutive times from the time of detection.
It detects and captures the time required to reach the specified value, and when the load does not reach the predetermined value, it is set to measurement mode.
Until the above-mentioned time has elapsed, the average value is displayed moment by moment with a small number of averaged data, and when the above-mentioned time has elapsed, it is judged that the measured value has stabilized, and the number of data for averaging is increased by 1@ order, and the average value is displayed. The reason is that it is configured to calculate and display.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The digitally converted data from the electronic load measuring mechanism 1 is outputted to the control section 3 via the input/output boat 2 minutely at minute intervals, for example, 0.2 seconds. The control unit 3 is composed of a microprocessor, and includes a central processing unit cPU, a read-only memory It OM , a random access memory RAM, and the like. The data introduced into the control unit 3 is stored in the data storage part of the random access memory RAM, and the data storage part of the random access memory RAM is provided with p+ data storage areas, and the latest sampling data do is stored in the data storage area of the random access memory RAM. Each time the data arrives, the oldest data is discarded, and therefore the data of dO*dl...dp is always stored. This random access memo IJR
In addition to the data storage section described above, the AM is used to store various calculation results and as various registers, which will be described later. A processing program to be described later is written in the read-only memory kOM of the control unit 3. Also to the control section 3. A keyboard 4 used for inputting various constants etc. is connected via the input/output board 2, and the input/output board 2. A display 6 for displaying calculated values is connected via an interface circuit 5.

Next, we will discuss the effect. FIG. 2 is a flowchart showing a processing program according to an embodiment of the present invention. STl and S T
2, the data in the random access memory RAM is shifted to the latest sampling data do
Incorporate. In Sr1, the average value Wo is calculated using the latest piece of data (e.g. 8 pieces), and if the average value Wo is 0, the number of sampling data is sequentially increased in STI 5 to 8T13 to calculate L pieces of data. The average value Wo of the data is calculated and the average value Wo of the L pieces is displayed in 8Tl 9 and s'r 14. W at 8T5.

If is not 0, it is determined by srg whether the Wo is greater than or equal to the weight value (full scale value), and if it is greater than the full scale value, the process proceeds to the calibration mode.1 In the calibration mode, the average value is calculated. Calculate the average value WO based on the number of sampling data 1 according to the value of the register N that is sequentially counted up by commanding the STB, that is, by converting N pieces of data into data (
At the same time, the response time measurement flag is set to 0NIC in s"r12, and the average value W6 of the above N pieces of data is displayed as 8T1g and 3T14. When the next sampling data do arrives in this state, STB Since the response time measurement flag is set to ON in , the process proceeds to 5T19, and in sTlg, it is determined whether the sampling data d is greater than or equal to the full scale value Wk,
Wl (if above 11, sampling data do is Wk
Wait for the following.

This STI 9 is provided to detect that the load on the electronic scale is removed in calibration mode 1.

When the removal of the load is detected at 5T19, the value of register M is counted up by 1 for each data sampling (Sr20), and waits until the sampling data do becomes 0 or less (8T22). 5T29 sets the zero or less passage flag to ON, and register J
is set to 1 (Sr24), and in that state, when the next sampling data do arrives, if the iyM excess flag is set to ON at 5T21, the
Proceed to T25, register at 5T25 and 5T26,
The values of ■ are sequentially counted up to 'Jma', and the average value W is determined by the number of data based on the value of J.

(Sr28, 5T29, 5T80゜s"r31) until the average value Wo of that one data becomes 0 a predetermined number of times (for example, 30) consecutively (Sr28, 5T29, 5T80゜s"r31), register M is stored at every data sampling. The value increases by one count, and if Wo is O for a predetermined number of consecutive times (a), the process advances to Sr12, and the value of the register M is transferred to the rest time register and used as the m value, and the response time is measurement flag.

The zero or less passing flag is reset to OFF and the calibration mode is ended. The above flow in this calibration mode is:
It has the meaning explained below.

No. 8 WJ is a characteristic diagram showing the step response waveform of the measured values when the load is removed in a general electronic scale, and the average value stabilizes and stops at 0# after the load is initialized. It turns out that it takes a certain amount of time. In the above-mentioned calibration method, the load removal is detected with 5Ti9, and from that point on, the register M is counted up by 1 for each data sampling, and it is stopped when the average value Wo reaches 01 a predetermined number of times in a row. It is determined that the time has come, and the value of the register M at that time is taken into the rest time register as the m value, and this m value corresponds to time t in FIG. Therefore, if the load that occurs in one calibration mode is a full-scale value, it can be said that when measuring a load that is less than that value, the data will become stationary after at most t time (m value) has elapsed.

Returning to the flowchart in Figure 2, if the average value W of one piece in 5T9i does not reach the full scale value Wk, proceed to the measurement step and determine the ratio of the average value Wo to the full scale value Wk. ,Wo/Wk is 26
% or less, JJo exceeds 5.2596, +L50% or less, exceeds 0.7.50% and 64% or less, the m value is multiplied by 0.8, and if it exceeds 64%, the m value is multiplied by m
shall be. (Sr83, 5T94.5T85, 5T86,
8T87, 5TAB.

5T89), this m' is the m value corrected by the ratio of the load to be measured to the full scale value, and this correction is based on the following.

The vibration period T of a general electronic scale is, P is the weight of the ring,
If W is the sum of the weight of the load and the weight of the load and k and zo are constant #7, then it is expressed as T''czk ('+vy on p7), and therefore the time required for it to come to rest is approximately proportional to the square root of the weight of the load. In asT40, the ratio of the measured load to the full scale value for which the 1m value was obtained is corrected by multiplying the square root of the value in stages ξ.
The value of register N is counted up when it is determined that a load has been applied when it is determined at T5, or the average (i! W.) of one piece of data is displayed until m is reached, and register N is When it exceeds the number, the number of data for calculating the average value is sequentially increased (K pieces) for each sampling, and the average value Wo based on that number of data is displayed.

As explained above, according to the present invention, when a load of more than a predetermined value near the full scale is placed, the mode is automatically shifted to the calibration mode, and the time required for the electronic scale to come to rest, which is unique to this electronic scale, is is detected and stored, and in the measurement mode, the average value is calculated and displayed moment by moment using a small number of averaged pieces of data until the time since the load was placed reaches the stored time mentioned above. When the memorized time mentioned above is reached, the measured value is assumed to be stable and the number of data for calculating the average value is sequentially increased for each data sampling and the calculated average value is displayed, so the responsiveness during load changes is As the load value stabilizes, a more accurate average value will be automatically calculated and displayed. The above points are as follows: 1. For example, when measuring a certain amount, by memorizing that certain amount in advance, you can find out the time required to accurately measure that load, and when automatically measuring a certain amount, you can quickly weigh the amount near that load. For example, if the time required for the sample to come to rest is 2 seconds, if the sample is introduced for 2 seconds and the sample is interrupted, the effect will be increased thereafter.

In addition, in the calibration method according to the present invention, when detecting the rest time, the time required for the measured value to stabilize at 0 after removing the load placed on the electronic scale is detected. load on? Differences in detected values due to the mounting method are less likely to occur, such as when detecting the time from when the load is placed until the measured value stabilizes, and it is possible to always collect accurate resting times. can.

[Brief explanation of the drawing]

'fJ1 is a block diagram showing the configuration of the embodiment of the present invention, FIG. 2 is a flowchart showing its processing program, and FIG.
The figure is a step response characteristic diagram of measured values in an electronic scale. 1...Electronic load measurement! l! disease. 2...Manpower output boat% 3...Control section, 6...
Display section. Patent applicant Shimadzu Corporation Patent attorney Nishi 1) Arata

Claims (3)

[Claims] (1)! means for sampling and storing the digital conversion data of the hole load measuring mechanism at predetermined time intervals; means for calculating the average value of the latest predetermined number of data for each sampling; Means for determining calibration mode or measurement mode when the value is greater than or equal to a predetermined value set near the full scale value, and 1. Detecting that the load on the electronic scale has been removed in the calibration mode, and using that detection as the reference point. and a calibration mode execution means for detecting and storing the time required for the average value to become 0 a predetermined number of times in succession. In the measurement mode, it detects that a load has been placed, and displays the average value of the predetermined number of data from that detection until the time required above is reached, and when the time required above is reached, the data is displayed sequentially for each sampling mentioned above. An electronic scale equipped with a measurement mode execution means that increases the number of numbers and calculates and displays the average value. (2) The electronic scale according to claim 1, wherein the predetermined value is the full scale value. (3) The electronic scale according to claim 1 or 2, wherein the electronic scale is configured to correct the required time in accordance with the ratio of the load to the full scale value in the top measurement mode.