CN214151425U - Control and driving system of material strength testing machine - Google Patents

Abstract

The utility model discloses a control and actuating system of material strength test machine, including microcontroller, drive circuit, the IGBT module, rectifier circuit, first AD conversion module and second AD conversion module, microcontroller's first output passes through drive circuit and is connected with the first input of IGBT module, rectifier circuit's output is connected with the second input of IGBT module, the output of first AD conversion module is connected with microcontroller's first input, the output of second AD conversion module is connected with microcontroller's second input. The utility model discloses simplified the distribution, reduced redundancy and occupation space, improved control accuracy, can realize the automatic switch of position, moment mode fast, response sensitivity is high, can prevent effectively that overshoot damage equipment has improved the reliable and stable nature. The utility model discloses but wide application in control technical field.

Description

Control and driving system of material strength testing machine

Technical Field

The utility model belongs to the technical field of the control technique and specifically relates to a control and actuating system of material strength test machine.

Background

The material strength testing machine is a device for judging the strength of a material by applying a certain force to a test piece and measuring the deformation degree of the test piece, is used for judging the mechanical property of the material and giving a quality index of a product, and is widely applied to the fields of material research, inspection and the like. The executing mechanism of the material strength testing machine mainly comprises a tension and pressure sensor, a position sensor, a motor, a driver and the like. The conventional servo driver and an alternating current servo motor are controlled by an independent controller to drag a screw rod to pressurize a test piece, the controller is required to realize positioning and moment control by switching the working mode of the servo driver, and the defects of complex wiring and programming, large occupied space, easy drift of a static position, poor control precision of a stress application process, large overshoot during material fragmentation and the like exist in the use process.

The noun explains:

IGBT: an insulated gate bipolar transistor is a composite fully-controlled voltage-driven power semiconductor device consisting of a BJT (bipolar junction transistor) and an MOS (insulated gate field effect transistor), and has the advantages of both high input impedance of an MOSFET (metal-oxide-semiconductor field effect transistor) and low conduction voltage drop of a GTR (GTR);

CPLD: the Complex Programming logic device adopts Programming technologies such as CMOS EPROM, EEPROM, flash memory and SRAM, and thus, a programmable logic device with high density, high speed and low power consumption is formed.

SUMMERY OF THE UTILITY MODEL

To solve the above technical problem, the utility model discloses an aspect's aim at: the control and drive system of the material strength testing machine is high in control precision, stable and reliable.

The utility model adopts the technical proposal that:

a control and drive system of a material strength tester comprises a microcontroller, a drive circuit, an IGBT module, a rectification circuit, a first AD conversion module and a second AD conversion module, a first output end of the microcontroller is connected with a first input end of the IGBT module through the driving circuit, the output end of the rectifying circuit is connected with the second input end of the IGBT module, the output end of the first AD conversion module is connected with the first input end of the microcontroller, the output end of the second AD conversion module is connected with the second input end of the microcontroller, the first output end of the IGBT module is used for being connected with the input end of an alternating current motor of the material strength testing machine, the input end of the first AD conversion module is used for being connected with the output end of a pressure sensor of the material strength testing machine, and the input end of the second AD conversion module is used for being connected with the output end of a position sensor of the material strength testing machine.

Furthermore, the control and drive system further comprises a monitoring and alarm circuit, wherein a first input end of the monitoring and alarm circuit is connected with a second output end of the IGBT module, and an output end of the monitoring and alarm circuit is connected with a third input end of the microcontroller.

Further, the monitoring and alarming circuit comprises a CPLD and a comparator, and the CPLD is electrically connected with the comparator.

Further, the control and drive system further comprises a current sampling circuit, a first output end of the current sampling circuit is connected with a fourth input end of the microcontroller, a second output end of the current sampling circuit is connected with a second input end of the monitoring and alarm circuit, and the current sampling circuit is used for detecting the current of the alternating current motor of the material strength testing machine.

Furthermore, the control and drive system further comprises a display module, and the input end of the display module is connected with the second output end of the microcontroller.

Furthermore, the control and drive system further comprises a key module, and the output end of the key module is connected with the fifth input end of the microcontroller.

Further, the microcontroller is an STM32F429 chip.

Further, the first AD conversion module is an ADs1230 chip.

Further, the second AD conversion module is an ADs7886 chip.

The utility model has the advantages that: the control and drive system of the material strength testing machine comprises a microcontroller, a drive circuit, an IGBT module, a rectifier circuit, a first AD conversion module and a second AD conversion module, wherein the microcontroller controls an alternating current motor of the material strength testing machine through the drive circuit and the IGBT module, so that on one hand, the functions of the controller and a driver are integrated, the wiring is simplified, the redundancy and the occupied space are reduced, on the other hand, a closed-loop control link is shortened, and the control precision is improved; the first AD conversion module and the second AD conversion module are used for collecting sensor data of the material strength testing machine, so that automatic conversion of position and moment modes can be rapidly realized, the response sensitivity is high, equipment can be effectively prevented from being damaged by overshoot, and the stability and reliability are improved.

Drawings

Fig. 1 is a block diagram of a control and driving system of a material strength testing machine according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a comparator according to an embodiment of the present invention;

fig. 3 is a schematic circuit connection diagram of a first AD conversion module according to an embodiment of the present invention;

fig. 4 is a schematic circuit connection diagram of a second AD conversion module according to an embodiment of the present invention;

fig. 5 is a block diagram of a material strength testing machine according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality is two or more, if there is a description that the first and the second are only used for distinguishing the technical features, but not understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the precedence of the indicated technical features.

In the description of the present invention, unless explicitly defined otherwise, the words such as setting, connecting and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention by combining the specific contents of the technical solutions.

Referring to fig. 1 and 5, the embodiment of the present invention provides a control and driving system for a material strength testing machine, which comprises a microcontroller, a driving circuit, an IGBT module, the first output end of the microcontroller is connected with the first input end of the IGBT module through the driving circuit, the output end of the rectifying circuit is connected with the second input end of the IGBT module, the output end of the first AD conversion module is connected with the first input end of the microcontroller, the output end of the second AD conversion module is connected with the second input end of the microcontroller, the first output end of the IGBT module is used for being connected with the input end of an alternating current motor of the material strength testing machine, the input end of the first AD conversion module is used for being connected with the output end of a pressure sensor of the material strength testing machine, and the input end of the second AD conversion module is used for being connected with the output end of a position sensor of the material strength testing machine.

The microcontroller controls the alternating current motor of the material strength testing machine through the driving circuit and the IGBT module, on one hand, the functions of the controller and the driver are integrated, wiring is simplified, redundancy and occupied space are reduced, on the other hand, a closed-loop control link is shortened, and therefore control precision is improved; the first AD conversion module and the second AD conversion module are used for collecting sensor data of the material strength testing machine, so that automatic conversion of position and moment modes can be rapidly realized, the response sensitivity is high, equipment can be effectively prevented from being damaged by overshoot, and the stability and reliability are improved.

Optionally, the utility model discloses the IGBT module comprises 6 IGBT power tubes, can drive alternating current servo motor.

Referring to fig. 1, as a further optional implementation manner, the control and driving system further includes a monitoring and warning circuit, a first input end of the monitoring and warning circuit is connected to the second output end of the IGBT module, and an output end of the monitoring and warning circuit is connected to a third input end of the microcontroller.

Specifically, the monitoring and alarming circuit is used for monitoring faults of overcurrent, overvoltage, undervoltage, overheating of the IGBT module and the like of the main circuit, on one hand, the signals are sent to the microcontroller for alarming and protecting actions, on the other hand, the output of the driving circuit of the IGBT module is directly forbidden, and the speed of the protecting actions is accelerated.

Further as an optional implementation mode, the monitoring and alarming circuit comprises a CPLD and a comparator, and the CPLD is electrically connected with the comparator.

Specifically, an undervoltage protection threshold, an overvoltage protection threshold, a total overcurrent protection threshold and the like are preset in the CPLD; the embodiment of the utility model provides an adopt LM393 comparator chip, as shown in FIG. 2 do the utility model provides a circuit connection schematic diagram of comparator, the comparator can compare voltage, the electric current of gathering with corresponding threshold value of predetermineeing to feed back the comparative result to microcontroller, issue corresponding control command according to the comparative result by microcontroller.

Referring to fig. 1 and 5, as a further optional implementation manner, the control and drive system further includes a current sampling circuit, a first output end of the current sampling circuit is connected to a fourth input end of the microcontroller, a second output end of the current sampling circuit is connected to a second input end of the monitoring and alarm circuit, and the current sampling circuit is used for detecting a current of an alternating current motor of the material strength testing machine.

Specifically, the utility model discloses current sampling circuit is used for gathering the motor current of material strength test machine to feed back the result to microcontroller and monitoring and warning circuit.

Referring to fig. 1, as a further alternative embodiment, the control and driving system further includes a display module, and an input terminal of the display module is connected to the second output terminal of the microcontroller.

Specifically, the display module of the embodiment of the present invention is an 800 × 480 dot matrix liquid crystal display, and displays the current pressure head position and pressure in the operating state; the state of the limit signal, the running of the motor, the alarm and other state signals can be displayed in the debugging state; in the setting state, a pressure curve can be set, a control strategy is selected, and parameters such as control gain, integral time, differential time and the like are set.

Referring to fig. 1, as a further alternative embodiment, the control and driving system further includes a key module, and an output terminal of the key module is connected to a fifth input terminal of the microcontroller.

Specifically, the key module is used for setting a control and driving system and inputting related parameters.

Further as an alternative embodiment, the microcontroller is an STM32F429 chip.

Specifically, the utility model discloses microcontroller adopts STM32F429 chip, and built-in DSP, AD converter, SPI interface, TFT LCD screen interface and PWM control logic circuit etc..

Further as an optional implementation manner, the first AD conversion module is an ADs1230 chip.

Specifically, first AD conversion module adopts ADS1230 signal conditioning chip, can be with pressure sensor's the pressure signal conversion of drawing digital signal to transmit to microcontroller, as shown in FIG. 3 be the embodiment of the utility model provides a first AD conversion module's circuit connection sketch map.

Further as an optional implementation, the second AD conversion module is an ADs7886 chip.

Specifically, second AD conversion module adopts ADS7886 analog-to-digital converter, can convert displacement sensor's position signal to digital signal to transmit to microcontroller, as shown in FIG. 4 be the embodiment of the utility model provides a second AD conversion module's circuit connection sketch map.

The system architecture of the embodiments of the present invention is explained above, and the embodiments of the present invention are further explained below with reference to specific embodiments.

The embodiment of the utility model is provided with a display module, a key module and a microcontroller, wherein the display module and the key module are connected with the microcontroller through parallel interfaces; the PWM output end of the microcontroller is connected to a driving circuit of the IGBT module, and the driving circuit controls the on-off of the IGBT module; the incoming line alternating current is changed into direct current by the rectifying circuit, and the IGBT module drives an alternating current servo motor of the material strength testing machine to rotate under the control of the microcontroller; the current sampling circuit collects the current of the motor, sends the current to an ADC input interface of the microcontroller and sends a current signal to the monitoring and alarming circuit; the monitoring and alarming circuit sends the alarming information to a digital quantity input interface of the microcontroller; the current angle of the motor shaft is detected by a rotary encoder and is sent to a rotary encoder interface circuit; the device is provided with an electronic ruler type displacement sensor input interface circuit and a strain type pressure sensor signal excitation and acquisition circuit, the current position of the screw is detected by a displacement sensor, the displacement is converted into a digital signal through the electronic ruler type displacement sensor input interface circuit (namely a first AD conversion module), and the digital signal is sent to the microcontroller through an SPI interface; the stress of the test piece is detected by a weighing sensor, and is excited and amplified by a strain bridge and sent to a microcontroller through an SPI interface by an analog-to-digital converter (namely a second AD conversion module).

The embodiment of the utility model provides a concrete work flow does: the alternating current is changed into direct current by the rectifying circuit and then is sent to the IGBT module, and the microcontroller selects a torque mode or a position mode according to the control requirement. In the position mode, the microcontroller calculates required control parameters according to the set speed, the target position and the current position sent by the position sensor, sends PWM pulses to the IGBT driving circuit to control the grid of the IGBT, changes direct current from the rectifying circuit into vector control voltage of the servo motor from the IGBT module, and drives the motor to rotate until the target position is reached; in the torque mode, the microcontroller calculates required control parameters according to the set pressure, the pressure change rate and the current pressure sent by the pressure sensor, and the output torque of the motor is controlled by adjusting the current of the motor, so that the stress of the test piece conforms to the set pressure curve.

The following specifically introduces the relevant operations of the embodiments of the present invention:

1) manual mode: the operations of ascending, descending, positioning, pressurizing, decompressing, position clearing, pressure zeroing and the like can be carried out through the keys;

2) the automatic mode is as follows: and matching with 'mode', 'single-section', 'continuous' and 'stop' keys, automatically performing feeding and pressurizing circulation operations according to the selected working cycle and pressure curve, and judging and displaying the results.

3) Setting mode: and (4) setting action types, feeding displacement, pause time, repetition times, set pressure, pressure increasing and reducing speed and the like by adopting a table filling mode. After the password is input, control parameters such as control gain, integral time, differential time and the like can be set.

4) Other functions are as follows: sudden stop, limit detection and overload detection.

The operation flow of the implementation example is as follows: after power-on, the pressure sensor is firstly adjusted to zero, and the zero position of the mechanism is determined. In the manual mode, a test piece is firstly placed on a supporting plate to be fixed, the position of a pressure head is adjusted by pressing an ascending key or a descending key, the deviation of pressure display is eliminated by pressing a zero setting key, the pressure of the test piece is adjusted by pressing a pressurizing key or a decompressing key, and the position sensor and the pressure sensor can be calibrated in the working mode.

Before the automatic operation, the setting work is firstly carried out: setting the action of each step of operation, such as descending and pressing, returning to zero, ending and the like; when the setting operation is feeding and pressing, a plurality of parameters such as feeding distance, a pressure set value, a pressure increasing rate, a pressure reducing rate, pause time, repetition times and the like are required to be displayed; in the automatic mode, pressing the "mode" key can select different program segments; pressing the "continue" button, the device operates at the steps given by the program until the program is finished or the "stop" button is pressed. Pressing the "stop" button may terminate the current operation, and then pressing the "continue" button may continue, and pressing the "single-segment" button may only execute one procedure at a time.

The embodiment of the utility model provides a have following advantage:

1) the control precision is high. A high-performance single chip microcomputer is used as a core, a closed-loop control chain is shortened, and a power driving circuit is controlled through an optimization control algorithm, so that first-order homodyne fitting of a pressure curve is achieved.

2) The work is stable and reliable. The microcontroller can directly and quickly realize automatic conversion of position and moment modes according to the current state, has high response sensitivity, and can effectively prevent overshoot from damaging equipment.

3) The structure is compact. The utility model discloses put the function integration of controller and driver together, reduced the volume, simplified outside distribution.

4) The application range is wide. The utility model discloses control strategies such as controller built-in current ring, pressure ring, speed ring and position ring can be according to application scenario selection control structure and adjustment parameter.

5) The cost is low. The utility model discloses with controller and driver integration together, reduced redundant parts such as microprocessor, power, practiced thrift the cost.

6) Is convenient to use. The utility model can display the current pressure head position, pressure, limit, overload and other states, alarm information and the like; the position of the pressure head can be manually adjusted, and the pressure curve can be set; the test cycle can be automatically completed, and the test conclusion can be judged and displayed.

As shown in fig. 5, the embodiment of the present invention provides a material strength testing machine, including:

the control and drive system of the material strength testing machine as described in the above embodiments;

the output end of the alternating current power supply is connected with the input end of the rectifying circuit;

the input end of the alternating current motor is connected with the first output end of the IGBT module;

the output end of the pressure sensor is connected with the input end of the first AD conversion module;

and the output end of the position sensor is connected with the input end of the second AD conversion module.

The embodiment of the utility model adopts the displacement sensor of the electronic ruler (such as TWY-02 type resistance displacement sensor) to detect the position of the pressure head, thus realizing the full closed loop control of the position loop; and a strain type pull pressure sensor (such as a TJH-4D spoke type weighing sensor) is adopted to detect the pressure applied to the test piece, so that the full-closed loop control of a pressure loop is realized.

Through the control and the drive system of the material strength testing machine, the material strength testing machine has at least the following beneficial effects: the control and drive system simplifies wiring, reduces redundancy and occupied space, thereby reducing the volume of the material strength testing machine and reducing production cost; the control precision of the control and drive system is improved, so that the test precision of the material strength test machine can be improved; the stability and reliability of the control and drive system are improved, so that the stability and reliability of the material strength testing machine and the service life of the material strength testing machine are improved.

While the preferred embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that the foregoing and various other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention.

Claims (9)

1. A control and drive system of a material strength testing machine is characterized in that: comprises a microcontroller, a driving circuit, an IGBT module, a rectifying circuit, a first AD conversion module and a second AD conversion module, a first output end of the microcontroller is connected with a first input end of the IGBT module through the driving circuit, the output end of the rectifying circuit is connected with the second input end of the IGBT module, the output end of the first AD conversion module is connected with the first input end of the microcontroller, the output end of the second AD conversion module is connected with the second input end of the microcontroller, the first output end of the IGBT module is used for being connected with the input end of an alternating current motor of the material strength testing machine, the input end of the first AD conversion module is used for being connected with the output end of a pressure sensor of the material strength testing machine, and the input end of the second AD conversion module is used for being connected with the output end of a position sensor of the material strength testing machine.

2. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the control and drive system further comprises a monitoring and alarm circuit, wherein a first input end of the monitoring and alarm circuit is connected with a second output end of the IGBT module, and an output end of the monitoring and alarm circuit is connected with a third input end of the microcontroller.

3. The control and drive system for a material strength testing machine as claimed in claim 2, wherein: the monitoring and alarming circuit comprises a CPLD and a comparator, and the CPLD is electrically connected with the comparator.

4. The control and drive system for a material strength testing machine as claimed in claim 2, wherein: the control and drive system further comprises a current sampling circuit, a first output end of the current sampling circuit is connected with a fourth input end of the microcontroller, a second output end of the current sampling circuit is connected with a second input end of the monitoring and alarm circuit, and the current sampling circuit is used for detecting the current of an alternating current motor of the material strength testing machine.

5. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the control and drive system further comprises a display module, and the input end of the display module is connected with the second output end of the microcontroller.

6. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the control and drive system further comprises a key module, and the output end of the key module is connected with the fifth input end of the microcontroller.

7. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the microcontroller is an STM32F429 chip.

8. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the first AD conversion module is an ADS1230 chip.

9. The control and drive system for a material strength testing machine as claimed in claim 1, wherein: the second AD conversion module is an ADS7886 chip.

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