CN112763753A

CN112763753A - Micro wireless acceleration real-time detection system and method for reciprocating impact mechanism

Info

Publication number: CN112763753A
Application number: CN202011607332.8A
Authority: CN
Inventors: 丁问司; 卿涛
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-05-07

Abstract

The invention is applied to the technical field of detection, and discloses a micro wireless acceleration real-time detection system and a method for a reciprocating impact mechanism, wherein the system comprises a main controller, a three-axis acceleration sensor, a Bluetooth module, a power supply module, terminal equipment and a fixing mechanism; the main controller, the three-axis acceleration sensor, the Bluetooth module and the power supply module are respectively and fixedly connected with a fixing mechanism, and the fixing mechanism is embedded in the reciprocating impact mechanism; the main controller is respectively connected with the three-axis acceleration sensor, the Bluetooth module and the power module; the three-axis acceleration sensor is used for acquiring the motion direction and the acceleration value of the reciprocating impact mechanism; the Bluetooth module is also in wireless connection with the terminal equipment. The detection system is small in size and convenient to install, and a reference point which is static relative to a tested object does not need to be set so as to directly measure the acceleration value of the impact piston.

Description

Micro wireless acceleration real-time detection system and method for reciprocating impact mechanism

Technical Field

The invention relates to the technical field of detection of motion characteristics of reciprocating hydraulic impact machinery, in particular to a micro wireless acceleration real-time detection system and method for a reciprocating impact mechanism.

Background

In studying the impact performance of reciprocating hydraulic impact mechanisms, dynamic velocity and displacement signals of the impact mechanism are often required. However, in many cases, it is difficult to obtain the velocity signal and the displacement signal of the impact mechanism, and even if the signals are not directly obtained by measurement, even if the signals can be measured by a precise instrument, the cost is too high, and the test device is difficult to install and is easy to damage. The current common methods include a stress wave method, a high-speed photography method, a photoelectric displacement differential method, an electromagnetic induction method, a contact method, an indicator diagram method, an air pressure method and the like. However, the above method cannot directly measure the speed and displacement of the impact mechanism, and it is very difficult to obtain the speed and displacement of the impact mechanism under the working condition, and it is necessary to set reference points when measuring the speed and displacement of the impact mechanism, and it is impossible to directly measure the object to be measured.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention provides a micro wireless acceleration real-time detection system and a method for a reciprocating impact mechanism.

The second purpose of the invention is to provide a micro wireless acceleration real-time detection method for the reciprocating impact mechanism.

In order to achieve the purpose, the invention adopts the following technical scheme:

a micro wireless acceleration real-time detection system for a reciprocating impact mechanism comprises a main controller, a three-axis acceleration sensor, a Bluetooth module, a power module, terminal equipment and a fixing mechanism;

the main controller, the three-axis acceleration sensor, the Bluetooth module and the power supply module are respectively and fixedly connected with a fixing mechanism, and the fixing mechanism is embedded in the reciprocating impact mechanism;

the main controller is respectively connected with the three-axis acceleration sensor, the Bluetooth module and the power module;

the three-axis acceleration sensor is connected with the reciprocating impact mechanism and is used for acquiring the motion direction and the acceleration value of the reciprocating impact mechanism;

the Bluetooth module is also in wireless connection with the terminal equipment.

Preferably, the fixing mechanism includes a cover member, a first fixing plate, a second fixing plate, and a third fixing plate;

the cover part is connected with the reciprocating impact mechanism to form a closed chamber;

the first fixing plate and the second fixing plate are respectively and fixedly connected with the reciprocating impact mechanism, and a first interlayer is formed by the first fixing plate and the second fixing plate at intervals in the closed cavity;

the third fixing plate is arranged in the first interlayer and is respectively fixedly connected with the first fixing plate, the second fixing plate and the reciprocating impact mechanism, and the third fixing plate and the cover part are separated in the closed cavity to form a second interlayer;

the power supply module is arranged in the second interlayer and is respectively connected with the cover component, the third fixing plate and the reciprocating impact mechanism;

and the main controller, the three-axis acceleration sensor and the Bluetooth module are arranged on the third fixing plate.

Preferably, the cover member is connected to the reciprocating impact mechanism by a screw.

As a preferred technical scheme, the main controller adopts an STM32F373RC controller and is provided with pins PE8 and PE9, and the pins PE8 and PE9 are both interrupt control interface pins;

the three-axis acceleration sensor adopts an ADXL345 three-axis acceleration sensor, is provided with INT1 pins and INT2 pins, is respectively connected with the PE8 pins and the PE9 pins and is used for interrupting the output of the three-axis acceleration sensor, and the INT1 pins and the INT2 pins are interrupt control pins.

As a preferred technical scheme, the main controller adopts an STM32F373RC controller and is provided with pins PB8, PB9 and PF6, and the pins PB8, PB9 and PF6 are a module serial port receiving interface, a module serial port sending interface and a module wake-up interface pin, respectively;

the Bluetooth module adopts an RF-BM-4044B4 Bluetooth module, is provided with RXD pins, TXD pins and BRTS pins, is respectively connected with the PB8 pins, the PB9 pins and the PF6 pins, and is used for waking up the module when a data sending request is sent, and the RXD pins, the TXD pins and the BRTS pins are respectively used for receiving a module serial port, sending the module serial port and waking up the module.

As a preferred technical scheme, the device also comprises a memory;

the memory is arranged on the third fixing plate, connected with the main controller and used for storing the motion direction and the acceleration value of the reciprocating impact mechanism.

As a preferable technical solution, the device further comprises an insulating member;

the insulating part is arranged in the second interlayer and is respectively connected with the third fixing plate and the reciprocating impact mechanism;

the insulating member is provided with a recess into which the power module is fitted.

In order to achieve the second object, the invention adopts the following technical scheme:

a micro wireless acceleration real-time detection method for a reciprocating impact mechanism comprises the following steps:

embedding a main controller, a Bluetooth module, a three-axis acceleration sensor and a power supply module in a reciprocating impact mechanism;

the terminal equipment sends a connection request signal through the terminal communication module, the main controller wakes up the Bluetooth module after receiving the connection request signal through the Bluetooth module, the Bluetooth module exits from the sleep mode, and the main controller establishes wireless connection with the terminal equipment through the Bluetooth module;

the terminal equipment sends a data acquisition command, and the main controller receives the data acquisition command through the Bluetooth module and then controls the three-axis acceleration sensor to acquire detection data of the reciprocating impact mechanism in real time, wherein the detection data comprises the movement direction and the acceleration value of the reciprocating impact mechanism;

the main controller receives acceleration data acquired by the triaxial acceleration sensor, performs gravity removal processing and unit conversion processing to obtain preprocessed data, and sends the preprocessed data to the terminal equipment through the Bluetooth module;

the terminal equipment receives the preprocessed data, analyzes and processes the preprocessed data through a terminal processing module to obtain analyzed data, and displays the analyzed data through a terminal display module, wherein the analyzed data comprises speed data, displacement data and impact performance data;

after the measurement is finished, the terminal equipment sends connection disconnection request information; the main controller enables the interrupt pins of the Bluetooth module after receiving the connection and disconnection request information through the Bluetooth module, the Bluetooth module is enabled to enter a sleep mode, and the main controller enables the interrupt pins of the three-axis acceleration sensor to be interrupted to acquire work.

As a preferred technical scheme, the method for analyzing the preprocessed data by the terminal processing module to obtain the analyzed data specifically comprises the following steps:

determining sampling frequency and test channel data; wherein the test channel data comprises X, Y, Z channels of a three-axis sensor;

selecting a channel to be analyzed for the detection data, sampling and intercepting to obtain intercepted data;

denoising and integrating the intercepted data to obtain speed data and displacement data;

calculating the speed data to obtain impact performance data; the impact performance data includes impact work, impact power, and impact frequency.

As a preferred technical solution, the integration processing adopts time domain integration or frequency domain integration, the frequency domain integration adopts frequency domain attenuation integration, and the time domain integration adopts a time domain integration method based on high-pass filtering.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention adopts the technical scheme of measuring the acceleration of the reciprocating impact mechanism, and the acceleration detection device is arranged in the reciprocating impact mechanism and applied to the field of vibration test, thereby solving the problem that the traditional test method has a plurality of restrictive factors in the process of obtaining the change of the impact motion parameters, for example, when the tested object is a hydraulic impactor, an electric pick, an electric hammer and other impact machines with narrow space and high-speed and high-frequency motion of an impact piston are difficult to directly measure the impact speed and the displacement parameters and can only carry out indoor test and the like, achieving the purpose of directly and rigidly connecting the tested object without setting a static reference point relative to the tested object so as to directly measure the acceleration value of the impact piston and obtaining the technical effects of the speed and the displacement of the impact mechanism through integration.

(2) The invention adopts the technical scheme that the three-axis acceleration sensor has high sensitivity and small size, and the overall size of the instrument is as small as possible on the premise of meeting the requirements of functions and quality, thereby solving the technical problems of overhigh cost, difficult installation of a testing device and the like of the traditional testing scheme and achieving the technical effects of simple installation, low cost and no damage to an impact mechanism.

(3) The invention adopts the Bluetooth module as the technical scheme of communication, solves the technical problems that the traditional test scheme acquires the acceleration signal in an off-line state and adopts WIFI as the communication means, and is limited to the communication only in the router environment, achieves the Bluetooth connection with the mobile equipment and the wireless communication, and achieves the technical effect of realizing remote real-time recording.

(4) The terminal equipment adopts the mobile terminal, and solves the problems that the traditional PC end upper computer is not easy to carry and is heavy; the technical effects that the user can analyze and process the collected acceleration data and visualize the result through the WebApp under different using terminals are achieved by combining the WebApp to adapt to different terminals.

Drawings

FIG. 1 is an overall block diagram of the mechanism of embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of pins of a host controller according to embodiment 1 of the present invention;

fig. 3 is a schematic diagram of a three-axis acceleration sensor pin according to embodiment 1 of the present invention;

fig. 4 is a schematic pin diagram of a bluetooth module according to embodiment 1 of the present invention;

FIG. 5(a) is a schematic structural view of a test impulse piston according to example 1 of the present invention;

FIG. 5(b) is an internal view of a test impulse piston according to example 1 of the present invention;

FIG. 5(c) is a sectional view taken along line B-B in FIG. 5(B) of example 1 of the present invention;

FIG. 5(d) is a top view of the sensor impact piston of FIG. 5(b) taken along direction A of example 1 of the present invention;

fig. 6 is a schematic view of a login interface of a terminal device according to embodiment 1 of the present invention;

fig. 7 is a waveform diagram of a terminal device according to embodiment 1 of the present invention based on recorded data;

wherein, 1-cover part, 2-power supply part, 3-first fixing plate, 4-second fixing plate, 5-third fixing plate.

Detailed Description

In the description of the present disclosure, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing and simplifying the present disclosure, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present disclosure.

Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item appearing before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

In the description of the present disclosure, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly unless otherwise explicitly stated or limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present disclosure can be understood in specific instances by those of ordinary skill in the art. In addition, technical features involved in different embodiments of the present disclosure described below may be combined with each other as long as they do not conflict with each other.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Examples

Example 1

As shown in fig. 1, the present embodiment discloses a micro wireless acceleration real-time detection system for a reciprocating impact mechanism, which includes a three-axis acceleration sensor, a main controller, a bluetooth module, a power module, and a terminal device; the main controller is respectively connected with the three-axis acceleration sensor, the Bluetooth module and the power module;

in this embodiment, the power module is used to supply power to other modules;

the terminal equipment comprises a terminal processing module, a terminal display module and a terminal communication module;

in the embodiment, the reciprocating impact mechanism adopts an impact piston; the main controller, the three-axis acceleration sensor, the Bluetooth module and the power supply module are embedded in the impact piston; the three-axis acceleration sensor collects detection data and sends the detection data to the main controller; the main controller removes gravity from the detected data, performs unit conversion processing to obtain preprocessed data and transmits the preprocessed data to the terminal communication module through the Bluetooth module; the Bluetooth module sends the received information to the terminal equipment, the terminal communication module transmits the preprocessed data to the terminal processing module for analysis processing to obtain analyzed data, and the terminal display module displays the analyzed data; wherein the detection data comprises the motion direction and acceleration value of the impact piston; the analytical data comprise speed data, displacement data and impact performance data, and the impact performance data comprise impact power, impact power and impact frequency.

In this embodiment, the system further comprises a memory, connected to the main controller, for storing the detection data;

as shown in fig. 2, the main controller adopts an STM32F373RC controller, and the operation modes of the STM32F373RC controller include a sleep mode, a stop mode, a standby mode and an operating mode; the typical power consumption of the STM32F3 series single chip microcomputer in the working mode is 2.7mA-7 mA; the typical power consumption in the standby mode is about 2uA, but the standby mode needs a specific wake-up pin for triggering, and the real-time performance is poor; typical power consumption in stop mode is around 20 uA; in practical application, the running mode of the STM32F373RC controller adopts a shutdown mode, and a 48-pin LQFP package with 7 x 0.5mm is adopted, so that the size is small and the power consumption is low;

in this embodiment, the main controller is in a sleep state when not operating, and operates by triggering and waking up; in this embodiment, the process of triggering to wake up the main controller includes: the terminal equipment sends a connection request signal to the main controller through the terminal communication module, the main controller receives the connection request signal through the Bluetooth module, the main controller wakes up the Bluetooth module to enable the Bluetooth module to exit a sleep mode, and the main controller inputs high level to RXD (RXD), TXD (TXD) and BRTS (BRTS) pins of the Bluetooth module (the pin level changes to cause a switching state); the main controller controls the three-axis acceleration sensor to acquire acceleration signals, and the three-axis acceleration sensor transmits detection data to the Bluetooth module through the main controller.

In this embodiment, when the terminal device transmits the disconnection request information, the main controller interrupts to make the triaxial acceleration sensor enter the sleep mode according to INT1 and INT2 pins of the triaxial acceleration sensor.

Referring to fig. 2, as shown in fig. 3, the three-axis acceleration sensor adopts an ADXL345 three-axis acceleration sensor, and the ADXL345 three-axis acceleration sensor adopts a 3 × 5 × 1mm 14-pin small ultrathin plastic package; in the embodiment, pins SD0, SDI, SCL, CS, INT1 and INT2 of the ADXL345 triaxial acceleration sensor are respectively connected with pins PB14, PB15, PD8, PA0, PE8 and PE9 of an STM32F373RC controller, wherein the SDI and SD0 are respectively serial data input and output pins; SCL and CS are respectively a serial port clock and a serial port enable pin; INT1 and INT2 are interrupt control pins, VDD and VS pins of the ADXL345 triaxial acceleration sensor are connected with a VCC end of a power supply, and three GND pins of the ADXL345 triaxial acceleration sensor are connected with a GND end; PB15 and PB14 are serial data input interface and output interface pins respectively; PD8 and PA0 are pins of a serial port clock interface and a serial port enable interface respectively; the pins PE8 and PE9 are interrupt control interface pins; in practical application, the detection system is installed as shown in fig. 5(b), and the direction perpendicular to the view a is the actual movement direction of the impact mechanism; the ADXL345 triaxial acceleration sensor can measure acceleration data of an X axis, a Y axis and a Z axis, and the output responses of the three acceleration sensitive axes can change relative to the gravity direction; according to the characteristics of the mounting device and the motion direction of the impact mechanism, which acceleration sensitive shaft is determined to be the actually measured direction of the impact mechanism, the reciprocating impact mechanism does reciprocating impact motion on the main shaft and can generate micro vibration on the upper side, the lower side, the left side and the right side, and therefore the other two sensitive shafts can be used for measuring the upper side, the lower side and the left side and the right side of the reciprocating impact mechanism. Acceleration data of the reciprocating impact mechanism in the X-axis direction, the Y-axis direction and the Z-axis direction are obtained in the above mode, and the data are sent to the main controller in a four-wire SPI mode; the INT1 and INT2 pins of the ADXL345 triaxial acceleration sensor are subjected to interrupt output by setting a high level, particularly interrupt enabling is carried out by setting an appropriate bit of an INT _ ENABLE register, and mapping to an INT1 pin or an INT2 pin is determined by setting an INT _ MAP register.

As shown in fig. 4, the bluetooth module is an RF-BM-4044B4 bluetooth module and is provided with a CC2640 chip, in this embodiment, RXD, TXD, and BRTS pins of the bluetooth module are respectively connected to PB8, PB9, and PF6 pins of an STM32F373RC controller; the RXD pins and the TXD pins are respectively a module serial port receiving end and a module serial port sending end; the BRTS pin is used for waking up the module when a data sending request is sent, the low level indicates that the host has data to send, and the high level indicates that the host does not have data to send; the PB8, PB9 and PF6 pins are a module serial port receiving interface, a module serial port sending interface and a module awakening interface pin respectively; the packaging size is 8 multiplied by 1 mm; in practical application, the Bluetooth module adopts a slave mode, the power consumption is 3.5mA, and the Bluetooth module has the characteristic of low power consumption.

In this embodiment, the power module is powered by a CR2032 battery, i.e., a 3V button-type lithium manganese battery, with a nominal voltage of 3.0V, a terminal voltage of 2.0V, a rated capacity of 200 and 230mAh, and a circular battery with a size of 20.0 × 3.2 mm.

In this embodiment, a power supply low dropout voltage regulator unit and a power supply filter circuit are arranged in the power supply module and used for providing stable working voltage for the bluetooth module and the main controller; in practical application, the working voltage of the Bluetooth module and the main controller is 3.3V.

In this embodiment, the terminal device adopts the mobile terminal, receives data through the bluetooth of the mobile terminal, processes the analytic processing through the processor of the mobile terminal to obtain analytic data, and then displays the analytic data through the APP of the mobile terminal.

In addition, the main controller, the bluetooth module, the power module, and the three-axis acceleration sensor are not limited to the specific models of the present embodiment, and the present invention is only taken as an example, and those skilled in the art can replace the main controller, the bluetooth module, the power module, and the three-axis acceleration sensor according to actual requirements.

In this embodiment, an acceleration detection method is adopted to detect acceleration, and includes the following steps:

firstly, initializing a system timer and a basic timer of a main controller, an ADXL345 triaxial acceleration sensor, a Bluetooth module and a power module; the system timer is used for monitoring the main control outer layer cycle of a connection request signal sent by the terminal equipment in real time; the basic timer is used for the main control inner layer circulation of the acceleration value collected by the three-axis acceleration sensor;

taking an acceleration value acquired by a triaxial acceleration sensor as detection data, increasing the data processing speed based on a DMA mode and an annular buffer queue, transmitting the detection data to terminal equipment through a Bluetooth module, and exiting the main control inner layer cycle when the sampling time set by a basic timer is reached;

in this embodiment, the ADXL345 triaxial acceleration sensor and the STM32F373RC controller communicate with each other by using the SPI, and the specific steps include the following: firstly, adding a bottom layer drive file spi.c and a source file spi.h supported by SPI under the hardware grouping of an STM32 controller in engineering, and simultaneously adding a bottom layer drive adxl.c source file and a corresponding head file adxl.h related to writing an ADXL345 triaxial acceleration sensor. The adxl.h contains definitions of sensor variables and the adxl.c source file contains conversion formulas for raw acceleration data.

In this embodiment, the RF-BM-4044B4 bluetooth module and the STM32F373RC controller communicate with each other using USART, and the specific steps include the following: in engineering, under the hardware grouping of an STM32F373RC controller, adding a bottom-layer driver usart3.c source file and a corresponding header file usart3.h header file, and simultaneously adding a bottom-layer driver blue.c source file and a corresponding header file blue.h for writing related Bluetooth modules.

In the embodiment, initializing the ADXL345 triaxial acceleration sensor, including initializing an SPI communication protocol, resetting the ADXL345 triaxial acceleration sensor, waking up the ADXL345 triaxial acceleration sensor, setting a sampling rate, closing an interrupt, closing a FIFO, and setting an x axis as a reference; calibrating the acceleration value through ADXL345_ AUTOAdjust; reading original data of the triaxial acceleration sensor through ADXL345_ ReadAverage; initializing the ADXL345 triaxial acceleration sensor portion also includes the read and write routines of the SPI interface for communication and data interaction with the STM32F373RC controller.

In this embodiment, the bluetooth module transmits the acquired acceleration data to the APP of the mobile terminal to process the data; in practical application, the STM32F373RC controller monitors a connection request signal sent before APP processing data of the mobile terminal based on a SysTick system timer, and when the STM32F373RC controller receives the connection request signal, the STM32F373RC controller wakes up the bluetooth module, and the bluetooth module exits the sleep mode; when the triaxial acceleration sensor carries out data acquisition, a basic timer is set to exit a sampling cycle through interruption so as to control sampling time.

As shown in fig. 5(a), 5(B), 5(c) and 5(d), the impact piston in the present embodiment includes a cover member 1, a first fixing plate 3, a second fixing plate 4, a third fixing plate 5 and a piston main body, and a measuring device and a power supply part 2 are embedded by fitting the cover member 1, the first fixing plate 3 and the second fixing plate 4 to a middle hollow groove of the piston main body, wherein the measuring device includes an STM32F373RC controller, an ADXL345 three-axis acceleration sensor, and an RF-BM-4044B4 bluetooth module;

as shown in fig. 5(b) and 5(c), the first fixing plate 3 and the second fixing plate 4 are perpendicular to the piston body respectively and are spaced apart to form a first interlayer, so that the third fixing plate 5 is disposed in the first interlayer, and the third fixing plate is fixedly connected to the first fixing plate 3 and the second fixing plate 4 respectively and is fixed in the empty groove of the piston body; the cover component 1 is connected with the piston main body and used for packaging the measuring device in the piston main body; the cover component 1 is detachable and fixable in a threaded manner so as to adjust the position of the internal measuring device, and is convenient for timely detachment and inspection when problems occur;

in the embodiment, an STM32F373RC controller, an ADXL345 triaxial acceleration sensor and an RF-BM-4044B4 Bluetooth module are fixedly arranged on a third fixing plate 5 respectively, and a CR2032 battery is connected with the STM32F373RC controller through insulated wires; as shown in fig. 5(b), 5(c) and 5(d), the CR2032 battery is connected to the cover member 1, the third fixing plate 5 and the reciprocating impact mechanism, respectively, and is disposed in a second interlayer formed by the cover member 1 and the third fixing plate 5 at a distance;

in the present embodiment, the third fixing plate 5 is a circular developing plate with a radius of 9 mm;

in this embodiment, an insulating member is further disposed in the impact piston and disposed in the second interlayer, and the insulating member is connected to the CR2032 battery and the piston body, in this embodiment, the insulating member is used to mount the CR2032 battery by cutting a phenolic cloth rod into a gasket and hollowing out a space in the middle of the cloth rod, which is the size of the button battery, that is, the insulating member is provided with a recess for placing the CR2032 battery; in the embodiment, a plurality of CR2032 batteries are adopted to reduce the installation area in a stacking way; in addition, if the insulating member takes other forms and structures, it needs to be modified adaptively, and the embodiment is not limited thereto.

As shown in fig. 6, the terminal display module needs to log in at a login interface, input a registered user name and password, click a login button, and enter a display interface. If the user is not registered, the user needs to register first, input a user name and an initial set password, and click a registration button to complete registration.

As shown in fig. 7, the graph is a drawing obtained by processing data acquired by the triaxial acceleration sensor in the terminal processing module, wherein the vertical axis represents the acquired acceleration, and the horizontal axis represents the operating time; through the terminal display module, experimenters can calculate and analyze the impact performance of the reciprocating impact mechanism in real time through the information.

Example 2

The embodiment also provides a micro wireless acceleration real-time detection method for the reciprocating impact mechanism, which comprises the following steps:

embedding a measuring device and a power supply module in the piston main body; the measuring device comprises a main controller, a Bluetooth module and a three-axis acceleration sensor;

the terminal equipment sends a connection request signal to the main controller through the terminal communication module, the main controller wakes up the Bluetooth module after receiving the connection request signal through the Bluetooth module, the Bluetooth module exits from a sleep mode, and the main controller establishes wireless connection with the terminal equipment through the Bluetooth module;

the terminal equipment sends a data acquisition command, the main controller receives the data acquisition command through the Bluetooth module and then controls the three-axis acceleration sensor to start to acquire detection data of the reciprocating impact mechanism in real time, and the main controller processes the acquired detection data to obtain preprocessing data, wherein the preprocessing data comprises gravity removal processing on data of a sensitive axis where gravity is located and conversion processing of units; the preprocessed data are sent to the terminal equipment through the Bluetooth module, the size of a serial port data packet can be indefinite, the length can be any value below 1024 bytes, the time for sending the data through the Bluetooth module needs to be reserved, and otherwise, the rear-end collision phenomenon can occur. Set up bluetooth module connection interval time as T20 ms in this embodiment, serial ports data packet length selects 36 bytes, and serial ports sends out packet interval Ts 20ms, can the most efficient use payload of communication like this, avoids communication full load operation again simultaneously. The detection data comprises the direction of piston movement and an acceleration value, wherein the direction of piston movement is characterized by the sign plus or minus of the acceleration value.

The terminal equipment transmits the preprocessed data to a terminal processing module for analysis processing to obtain information such as a motion parameter oscillogram, a speed displacement and the like of the reciprocating impact mechanism, and the information is displayed through a terminal display module; the concrete analysis processing steps comprise: first, the WebApp will determine the sampling frequency and valid test channel data (X, Y, Z channels for a tri-axial sensor) from the selected file. The channel to be analyzed can be selected, sampling and interception are carried out to obtain intercepted data, and the intercepted data are analyzed. The intercepted signal can be denoised and integrated according to the parameters set by the user. The denoising algorithm adopts a wavelet modulus maximum denoising algorithm based on SURE adaptive threshold, the integration algorithm can select time domain integration or frequency domain integration, the frequency domain integration selects frequency domain attenuation integration, the time domain integration method adopts a time domain integration method based on high-pass filtering, and the algorithms are integrated in the WebApp. After the velocity and the displacement are obtained through integration, the velocity can be calculated to obtain impact power, impact power and impact frequency, and therefore the impact performance of the impact mechanism is obtained.

(1) Impact work (w)

And after the maximum speed of the impact piston is measured, calculating by using a formula.

The impact work calculation formula is as follows:

in the formula: m is the impact piston mass and v is the maximum impact piston velocity.

(2) Frequency of impact (f)

The impact frequency is another important index reflecting the impact performance of the reciprocating impact mechanism, and represents the number of times of impacting the hammer by the impact piston in unit time, namely the reciprocal of the motion period of the impact piston. Unit: hz. When the impact work is tested, the number n of the maximum impact speed values in the time t is recorded by analyzing the recorded impact characteristic curve, and then the actual measured impact frequency can be obtained by calculating f to n/t. In addition, the impulse frequency can also be directly obtained by performing FFT conversion and spectrum correction on the acquired signal by a program through a signal processing technology.

(3) Impact Power (P)

The impact power P refers to the output power of the reciprocating impact mechanism and is a comprehensive evaluation index of the working capacity of the reciprocating impact mechanism. Unit: kW. The impact power is calculated after the impact power and the impact frequency are measured or calculated, and the calculation formula is as follows:

P＝10^-3Wf

in the formula: w is the impact work and f is the impact frequency.

After the measurement is finished, the terminal equipment sends connection disconnection request information; the main controller enables the interrupt pins of the Bluetooth module after receiving the connection and disconnection request information through the Bluetooth module, the Bluetooth module is enabled to enter a sleep mode, and the main controller enables the interrupt pins of the triaxial acceleration sensor to interrupt the triaxial acceleration sensor to acquire work.

In the embodiment, the performance of the denoising algorithm is evaluated based on the running time of the algorithm for processing data once, the signal-to-noise ratio (SNR) and the root Mean Square Error (MSE); evaluating the performance of an integration algorithm based on the average error (AME) and the root mean square error;

wherein, root mean square error:

signal-to-noise ratio:

average error:

x (k) is the true value,

is an estimated value;

the above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A micro wireless acceleration real-time detection system for a reciprocating impact mechanism is provided with a main controller and is characterized by further comprising a three-axis acceleration sensor, a Bluetooth module, a power module, terminal equipment and a fixing mechanism;

2. The system according to claim 1, wherein the fixing mechanism comprises a cover member, a first fixing plate, a second fixing plate, a third fixing plate;

3. The system according to claim 2, wherein the cover member is connected to the reciprocating impact mechanism by a screw thread.

4. The miniature wireless acceleration real-time detection system for the reciprocating impact mechanism according to claim 1, wherein the main controller adopts an STM32F373RC controller, and is provided with pins PE8 and PE9, and the pins PE8 and PE9 are interrupt control interface pins;

5. The micro wireless acceleration real-time detection system for the reciprocating impact mechanism according to claim 1, wherein the main controller is an STM32F373RC controller and is provided with PB8, PB9 and PF6 pins, and the PB8, PB9 and PF6 pins are a module serial port receiving interface, a module serial port sending interface and a module wake-up interface pin respectively;

6. The miniature wireless acceleration real-time detection system for a reciprocating impact mechanism according to any one of claims 2-5, further comprising a memory;

7. The miniature wireless acceleration real-time detection system for a reciprocating impact mechanism according to any one of claims 2-5, further comprising an insulating member;

8. A micro wireless acceleration real-time detection method for a reciprocating impact mechanism is characterized by comprising the following steps:

9. The method for detecting the micro wireless acceleration of the reciprocating impact mechanism in real time according to claim 8, wherein the analysis processing of the preprocessed data by the terminal processing module to obtain the analyzed data specifically comprises the following steps:

10. The method for detecting the miniature wireless acceleration of the reciprocating impact mechanism in real time as claimed in claim 9, wherein the integration processing adopts time domain integration or frequency domain integration, the frequency domain integration adopts frequency domain attenuation integration, and the time domain integration adopts a time domain integration method based on high-pass filtering.