In industrial applications, the Angle difference is a multi-load cell group scale system
It is an important source of error, which will affect the accuracy and stability of weighing
Qualitative. The angular difference refers to the situation where, under the same weight, different load cells
There are differences among the displayed readings, and such differences may be caused by multiple factors
The factors causing it include manufacturing errors of the load cell and inaccurate installation
Accuracy, signal interference, etc. And the bearing composed of analog load cells
The carrier, due to the indiscernibility of the signal, needs to be weighed each time during calibration
Weights are added to the sensor and the potentiometer in the junction box is used to measure the angular difference
Adjustments are made, but there are interactions among the various load cells
However, it requires repeated and multiple adjustments, which greatly increases the enterprise's costs [1]. Therefore
A multi-load cell group scale system without Angle difference adjustment has been designed in practice
It has significant advantages in application and helps improve the accuracy of industrial processes
Accuracy and efficiency, while reducing operating costs.
1
Angle difference adjustment of the multi-load cell group scale system
The multi-load cell group scale system is to place the heavy object on the load-bearing device
Under the action of gravity, the output is converted by the analog load cell and the weight value
Proportional analog signals are then aggregated and connected to the junction box to form an analog scale
The heavy instrument collects the output of the junction box, processes the data and then converts it
The weight data is directly displayed. A scale system with multiple load cells
The block diagram is shown in Figure 1. Multiple load cells can be combined to form a scale system
It is uniformly divided into analog weighing display instruments, junction boxes and load-bearing devices (analog)
It consists of three parts: the load cell, the force transmission and limit mechanism, and the load-bearing platform
Composition. Usually, for angular difference testing, a certain 砝 needs to be added to the carrier
The weights are initially calibrated [2]. After the calibration is completed, the weights are removed and the process is resumed
Four-corner error test. Place an appropriate amount of weights respectively as shown in Figure 1
The positions marked with "①", "②", "③" and "④"
Set it to each corner of the carrier and check the displayed value of the instrument against the actual situation
The error between values. When there is an error, it is necessary to adjust the eccentricity and out-of-tolerance
The potentiometer corresponding to the analog load cell is adjusted for the angular difference. by
There is an interaction with the analog load cell, so a reverse is required
It takes many adjustments to meet the requirements, and this adjustment process is very cumbersome.
It's time-consuming. By deeply analyzing the factors that cause angular differences, this paper develops a
This new type of bridge plate can be used in a multi-load sensor group scale system
Achieve high-precision measurement without relying on subsequent cumbersome and time-consuming angles
Differential adjustment directly provides a solution without angular differential adjustment.
The circuit schematic diagram of this new type of bridge group board is shown in Figure 2, bridge group board
All surface mount resistors are adopted, and the innovation lies in the arrangement at the output end
The configuration points of the three Z resistors are marked as Z1, Z2 and Z3 respectively. the
The purpose of the circuit design is to obtain the Z resistance on both sides of the bridge circuit
The "highest symmetry" means making the combined value of Z1 and Z3 as close as possible
Approach the value of Z2 to ensure the stability of the entire weighing sensor group scale system
Minimize the angular difference. This article adopts "maximum symmetry" instead of "absolute symmetry".
This discussion is because electronic component manufacturers aim to simplify the resistance value
Specification management follows a standardized series of resistance values, namely EIA
Standard. The common ones available on the market include E6, E12, E24, E48, and E96.
Series such as E192, these series provide the production and selection of resistance values
Standardized options have been provided. In actual production, enterprises need counterweights
Material management costs and system accuracy requirements. For low accuracy grades
For the weighing sensor group scale system, the resistance of the E48 series is usually sufficient
No Angle difference adjustment is required now. However, for those who pursue a higher level of accuracy
For the scale assembly system, it may be necessary to adopt more precise E96 series resistors.
To ensure that the system can meet the required high-performance standards. Through this
The method can achieve the maximum symmetry of Z resistance, thus truly realizing it
The high-accuracy grade load cell group scale system now features no Angle difference adjustment
Festival.
3
Verification of no Angle difference adjustment in multi-load cell systems
To verify the advantages of the new type of bridge plate in angular difference performance, it is necessary
Carry out a series of detailed and strict tests, including comparative trials, to
Comprehensively assess the angular difference performance. This article presents two verification test methods
The method refers to simulating the group scale test on the force machine and the group scale test on the platform. tong
Through two comprehensive performance evaluation tests, a new one can be determined more accurately
Has the type group bridge plate truly achieved no Angle difference adjustment?
3.1
Verification of the performance without angular difference in the force-mechanical simulation group scale
In a multi-load cell group scale system, the Angle difference is not only affected by electrical signals
The influence is also affected by the stiffness of the load-bearing, which has an impact on the weight of the test
Revenge is particularly crucial. To more accurately reflect the influence of electrical signals, especially
It is the specific influence of the diagonal difference of the Z resistance asymmetry, simulated on the force machine
Group scale testing provides a more intuitive evaluation method. This test adopts
Eight analog load cells were used (numbered 1#, 2#...) "8#"
And they were randomly mixed and assembled into six units based on four load cells
The scale assembly system is specially designed with three different Z resistance asymmetry conditions
In the first case, the asymmetry value is less than 1Ω, and in the second case, the asymmetry value
It is less than 3Ω. The third situation is that the asymmetric value is less than 7Ω. Such a design intention
In an in-depth analysis of the impact of Z resistance asymmetry on the scale Angle difference of the force machine simulation group
Physical influence