CN220356303U - Automatic zero setting system of meeting an emergency - Google Patents

Abstract

The utility model provides an automatic strain zeroing system, which comprises: a gain amplifier for amplifying an inputted strain input signal; the filter is used for filtering the acquired and amplified strain signals; and the microcontroller is used for collecting the deviation of the strain from the zero point, and processing and analyzing the corresponding data to form a real-time closed loop. The scheme of the utility model improves the zeroing precision by using the high-precision analog-to-digital conversion chip, can perform a large-scale zeroing operation, saves zeroing time, improves channel consistency, improves zeroing efficiency, has a storage function, can respectively store setting parameters of absolute zeroing sites and relative zeroing sites, and can be directly applied to the next system power-on.

Description

Automatic zero setting system of meeting an emergency

Technical Field

The utility model relates to an automatic strain zeroing system, in particular to an automatic strain zeroing system.

Background

In industrial field application, when a resistance strain gauge sensor is used for measuring a strain value, the zero point of a signal is influenced by factors such as the difference of individual operation of the resistance strain gauge, loss of a transmission line, temperature drift and the like. The fixing of the initial zero point influences the effective range of the input signal, and has important significance on the actual measurement data. For example: in a system with a strain signal range of + -10 milli-strain, assuming that the zero potential is placed at 1 milli-strain, the actual range will become a range of-11 milli-strain to 9 milli-strain, and the positive range will be reduced by 1 milli-strain. Therefore, the strain signal must be zeroed prior to acquisition.

The traditional zeroing mode is divided into two modes, namely software zeroing and hardware zeroing. The software zeroing is to change the value of the default zero point by writing corresponding parameters in the program, and the influence of the signal range cannot be recovered although the mode is simple. The hardware zeroing is to add a potentiometer on the constant voltage power supply strain bridge, which is similar to taking the bridge circuit as a sliding rheostat, or manually toggle the sliding rheostat in a parallel resistor mode, so that the output of the strain gauge reaches an initial zero position. However, the manual zeroing mode is complicated in operation and cannot be dynamically adjusted. Not only is personnel required to walk to each position and a large amount of debugging and measuring time is occupied, but also some special geographical positions exist in industry and do not have the condition of manual zero setting. And the manual adjustment has low accuracy and poor consistency, and can cause irrecoverable influence on the acquisition of subsequent data. With the development of electronic technology, the automatic zeroing mode gradually replaces manual zeroing.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a strain automatic zero setting system which can effectively reserve the original measuring signal range and has lower cost compared with an input voltage zero adjusting point.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

a strain auto-zeroing system comprising:

a gain amplifier for amplifying an inputted strain input signal;

the filter is used for filtering the acquired and amplified strain signals;

and the microcontroller is used for collecting the deviation of the strain from the zero point, and processing and analyzing the corresponding data to form a real-time closed loop.

In a preferred embodiment, the strain auto-zeroing system further comprises:

and the data storage module is connected with the microcontroller and is used for storing and reading zero potential by using an SPI protocol.

In a preferred embodiment, the strain auto-zeroing system further comprises:

the digital-to-analog conversion module is connected with the microcontroller and used for outputting an initial reference voltage to the gain amplifier, zero offset voltage generated by the gain amplifier and voltage output by the digital-to-analog conversion module are mutually overlapped, and strain signals are sent to the external acquisition device after gain amplification.

In a preferred embodiment, the gain amplifier comprises an operational amplifier and a gain resistor for amplitude amplifying the input small signal;

the filter consists of an RC device and is used for filtering interference and noise signals beyond the cut-off frequency;

the microcontroller is used for collecting the strain signals and processing the collected strain signals to output digital signals;

and the digital-to-analog converter is used for converting the digital signal output by the microcontroller into an analog signal.

The scheme of the utility model at least comprises the following beneficial effects:

in the above-described aspects of the present utility model,

according to the utility model, by injecting a small current zero setting mode, the zero point of the system is adjusted on hardware, the original measuring signal range can be effectively reserved, and compared with the zero point of the input voltage adjustment, the zero point adjustment method is lower in cost.

The utility model replaces the complicated operation of manual zero setting, improves the zero setting precision by using the high-precision analog-to-digital conversion chip, can perform the zero setting operation in a large range, saves the zero setting time, improves the channel consistency, improves the zero setting efficiency, has a storage function, can respectively store the digital-to-analog conversion setting parameters at the absolute zero point and the relative zero point, and can be directly applied in the next system power-on.

Drawings

Fig. 1 is an exploded view of the strain auto-zero system of the present utility model.

In the figure: 1. the device comprises a strain input signal 2, a gain amplifier 3, a filter 4, an output signal 5, a digital-to-analog conversion module 6, a microcontroller 7 and a data storage module.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As shown in fig. 1, the present utility model provides a strain auto-zeroing system comprising:

a gain amplifier 2 for amplifying an inputted strain input signal 1;

a filter 3 for filtering 4 the amplified strain input signal 1;

and the microcontroller 6 is used for collecting the deviation of the strain from the zero point, processing and analyzing the corresponding data to form a real-time closed loop.

In the utility model, the complicated operation of manual zero setting is replaced, the zero setting precision is improved by using the high-precision analog-to-digital conversion chip, the large-range zero setting operation can be performed, the zero setting time is saved, the channel consistency is improved, the zero setting efficiency is improved, the digital-to-analog conversion setting parameters in the process of absolute zero position and relative zero position can be respectively stored, and the digital-to-analog conversion setting parameters can be directly applied in the next system power-on.

As shown in fig. 1, the strain auto-zeroing system further comprises:

a data storage module 7 connected to the microcontroller 6 and configured to store the voltage signal;

the digital-to-analog conversion module 5 is connected with the microcontroller 6 and is used for outputting an initial reference voltage to the gain amplifier 2, zero offset voltage generated by the gain amplifier 2 and voltage output by the digital-to-analog conversion module 5 are mutually overlapped, and strain signals are sent to an external acquisition device after gain amplification and filtration.

As shown in fig. 1, the gain amplifier 2 includes an operational amplifier and a gain resistor for amplifying the amplitude of an input small signal;

the filter consists of an RC device and is used for filtering interference and noise signals beyond the cut-off frequency;

the microcontroller is used for collecting the strain signals and processing the collected strain signals to output digital signals;

and the digital-to-analog converter is used for converting the digital signal output by the microcontroller into an analog signal.

In the utility model, the filter consists of an RC device, and has the function of passing the components smaller than the cut-off frequency in the input signal, filtering noise or interference signals higher than the cut-off frequency, and obtaining a cleaner strain signal after the filter is used for processing. The microcontroller is internally provided with an analog-to-digital converter which firstly collects strain signals in an unbalanced state, ^then Converting the continuous analog signal into digital signals which can be processed by the microcontroller, and then compensating the acquired digital signals by the microcontrollerThe result is immediately sent to a high-precision digital-to-analog converter, which correspondingly reduces the imbalance value of the strain by means of a hardware compensation circuit. And then the analog-digital converter acquires the compensated unbalanced strain signal again, the micro-control processes the residual unbalanced value, the digital-analog converter compensates and outputs again, and the process is repeated until the residual unbalanced strain signal is smaller than a preset zero-setting cut-off signal, and the zero-setting process is finally finished.

In the present utility model, the microcontroller 6 is an STM32 microcontroller. After amplified strain data is acquired by using an STM32 microcontroller with an analog-to-digital conversion (ADC) function, the data is processed and analyzed, and then the STM32 microcontroller controls a digital-to-analog conversion module 5 (DAC) to output a proper voltage signal to form a real-time closed loop, so that the requirement that an original signal reaches an initial zero position is met. And the storage chip stores and records the parameters output by the digital-to-analog conversion module 5 at zero bit time. Compared with the traditional strain automatic zeroing system, the design completely realizes automation, is convenient to operate and use, reduces zeroing times by using a storage function, and improves zeroing efficiency to a great extent and some external influence factors. The method can realize large-scale zeroing, saves a large amount of zeroing time and solves the problem of precision error.

When the STM32 microcontroller is powered on, firstly, a zero point error value is acquired through the digital-to-analog conversion module 5, and the STM32 microcontroller which receives the zero point error value sends out a digital signal for compensating the zero point error value to the error value, and the digital signal is converted into an analog signal through the digital-to-analog conversion chip. And the superposition enters the zeroing system in a mode of injecting small current. The digital-to-analog conversion module 5 and the high-precision analog-to-digital conversion chip are circularly processed for a plurality of times to form a real-time closed loop, when the signal output value approaches to the zero potential, the STM32 microprocessor finishes adjusting the parameters of the digital-to-analog conversion chip to keep the final state, and the storage chip stores and records the parameters output by the digital-to-analog conversion module 5 at the moment.

If the system is powered off and powered on again, the STM32 microcontroller can firstly read the voltage parameters stored in the data storage module 7 before power off for application, and the effect that the strain value is at the zero point can be directly achieved under the condition that the strain is not changed.

While the foregoing is directed to the preferred embodiments of the present utility model, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims (4)

1. A strain auto-zeroing system, comprising:

a gain amplifier (2) for amplifying an input strain signal (1);

a filter (3) for filtering the amplified strain signal (1);

and the microcontroller (6) is used for acquiring the filtered strain signals, processing and analyzing the corresponding data, and outputting digital signals to the digital-to-analog conversion module to form a real-time closed loop.

2. The automatic strain zeroing system of claim 1, further comprising:

and the data storage module (7) is connected with the microcontroller (6) and is used for storing voltage signals.

3. The automatic strain zeroing system of claim 2, further comprising:

the digital-to-analog conversion module (5) is connected with the microcontroller (6) and is used for outputting an initial reference voltage to the gain amplifier (2), and zero offset voltage generated by the gain amplifier (2) and voltage output by the digital-to-analog conversion module (5) are mutually overlapped and are subjected to gain amplification, and then strain signals are sent to an external acquisition device.

4. A strain auto-zeroing system according to claim 3, characterized in that the gain amplifier (2) comprises an operational amplifier and a gain resistor for amplitude amplifying an input small signal;

the filter consists of RC devices and is used for filtering interference and noise signals;

the microcontroller is used for collecting the strain signals and processing the collected strain signals to output digital signals;

and the digital-to-analog converter is used for converting the digital signal output by the microcontroller into an analog signal.