Closed-loop servo control system of dynamic compression-shear testing machine

Abstract

The utility model discloses a closed-loop servo control system of a dynamic compression-shear testing machine, which belongs to the technical field of electrical control of testing machines and comprises a controller and a servo actuator, and the servo actuator is provided with an electro-hydraulic servo valve, a displacement sensor and a load sensor. The displacement sensor is connected with an input port X7 of the controller through a displacement sensor amplification conditioning circuit; the load sensor is connected with an input port X14 of the controller through a load sensor amplification conditioning circuit; and the electro-hydraulic servo valve is connected with an output port X18 of the controller through a servo valve driving circuit. According to the utility model, the axial controller, the horizontal controller and the corner controller are used for controlling the corresponding loading oil cylinders, and the displacement sensor and the load sensor in the servo actuator are used for carrying out position detection and pressure detection on a controlled unit, so that more accurate position control and force control are obtained; therefore, errors generated in the transmission process between the hydraulic station and the oil cylinder are eliminated, and the working precision of equipment is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrical control of testing machines, and particularly relates to a closed-loop servo control system for a dynamic compression-shear testing machine. Background Art

[0002] A compression-shear testing machine is a physical property testing instrument widely used in the field of materials science. It can be used for compression and bending tests of industrial components, and can also be used for testing the mechanical properties of materials such as large steel structural components, reinforced concrete structural components, and masonry structural components.

[0003] In a dynamic compression-shear testing machine, the load applied to the specimen has characteristics such as high speed, instantaneity, and strong impact. Therefore, the dynamic testing machine needs to perform test sampling at a higher frequency, which is very different from a static testing machine. Moreover, dynamic tests require sensors to feedback data in a timely and effective manner, and the requirement for control accuracy is also higher. After retrieval, the existing technologies mainly focus on the optimization and innovation of the structural hardware of the dynamic compression-shear testing machine. At present, there is still a lack of a set of efficient and reliable servo control systems for dynamic compression-shear testing machines to achieve the automatic control of dynamic compression-shear testing machines.

[0004] Based on the problems in the above background art, the R & D personnel have proposed a closed-loop servo control system for a dynamic compression-shear testing machine. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a closed-loop servo control system for a dynamic compression-shear testing machine to solve the problem that there is still a lack of a set of efficient and reliable servo control systems for current dynamic compression-shear testing machines.

[0006] To solve the above problems, the technical solution of the utility model is as follows:

[0007] A closed-loop servo control system for a dynamic compression-shear testing machine includes a controller and a servo actuator. An electro-hydraulic servo valve, a displacement sensor, and a load sensor are arranged on the servo actuator;

[0008] The displacement sensor is connected to the input port X7 of the controller through a displacement sensor amplification and conditioning circuit; the load sensor is connected to the input port X14 of the controller through a load sensor amplification and conditioning circuit; the electro-hydraulic servo valve is connected to the output port X18 of the controller through a servo valve drive circuit.

[0009] Further, there are three groups of the above-mentioned controllers, namely the axial controller, the horizontal controller, and the rotation angle controller. Each group of controllers is connected to a servo actuator that matches it. The sensors on the servo actuator monitor the corresponding displacements and loads in real time from three channels: the axial direction, the horizontal direction, and the rotation angle direction, and feed the axial displacement data and axial load data back to the axial controller; the horizontal displacement data and horizontal load data are fed back to the horizontal controller; the rotation angle displacement data and rotation angle load data are fed back to the rotation angle controller.

[0010] Further, the three groups of controllers achieve synchronous signal connection through the synchronous input port X11 and the synchronous output port X12. Through the synchronous signal connection, it can be ensured that each controller obtains consistent information at the same time node, thus avoiding system instability caused by time differences.

[0011] Further, the three groups of controllers are all connected to the network switch through the output port X16.

[0012] Further, the network switch is connected to the upper PC, and the upper PC displays the changes of each parameter and issues control instructions.

[0013] Further, the controller adopts STM32F429VGT6 with an ARM architecture, and is externally connected with an A / D chip AD7779 and a D / A conversion chip LTC1668. PID control is established through the above-mentioned controller, actuator, controlled object, and feedback system.

[0014] The beneficial effects of the present utility model are as follows:

[0015] (1) Aiming at the characteristics of high speed, instantaneity, and strong impact of the load on the specimen in the dynamic compression-shear test, the present utility model adopts three groups of controllers in the axial direction, the horizontal direction, and the rotation angle direction to control the corresponding loading cylinders, and uses displacement sensors and load sensors on the servo actuator to perform position detection and pressure detection on the controlled unit, so as to obtain more accurate position control and force control, thereby eliminating the errors generated during the transmission process between the hydraulic station and the cylinder.

[0016] To sum up, open-loop control is difficult to meet the control requirements of this system, while the full closed-loop control system can not only eliminate or reduce actual disturbances, but also is not very sensitive to fluctuations in the parameters of its own components. Therefore, the present utility model designs a "PC + MCU" control mode, establishes a closed-loop PID control through the controller, actuator, controlled object, and feedback system, realizes more accurate control of the dynamic compression-shear testing machine, and improves the working accuracy of the equipment.

[0017] (2) The utility model realizes the connection of synchronous signals through the X11 and X12 ports of the controller, and is connected to the network switch controlled by the upper computer, which can ensure that each controller obtains consistent information at the same time node, ensure that each parameter is uploaded and fed back in time, further eliminate or reduce the control error, and make the dynamic compression-shear testing machine operate more stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the electrical principle block diagram of the utility model.

[0019] Figure 2 It is the wiring diagram of the axial controller of the utility model.

[0020] Figure 3 It is the wiring diagram of the horizontal controller of the utility model.

[0021] Figure 4 It is the wiring diagram of the corner controller of the utility model.

[0022] The reference numerals are as follows: 101, controller; 101-1, displacement sensor amplification and conditioning circuit; 101-2, load sensor amplification and conditioning circuit; 101-3, servo valve drive circuit; 104, servo actuator; 104-1, displacement sensor; 104-2, load sensor; 105, network switch; 106, upper PC. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the technical solutions in the embodiments of the present utility model will be described with reference to the drawings in the embodiments of the present utility model.

[0024] As Figure 1 shown, a closed-loop servo control system of a dynamic compression-shear testing machine includes a controller 101 and a servo actuator 104. An electro-hydraulic servo valve, a displacement sensor 104-1, and a load sensor 104-2 are arranged on the servo actuator 104; the displacement sensor 104-1 is connected to the input port X7 of the controller 101 through a displacement sensor amplification and conditioning circuit 101-1; the load sensor 104-2 is connected to the input port X14 of the controller 101 through a load sensor amplification and conditioning circuit 101-2; the electro-hydraulic servo valve is connected to the output port X18 of the controller 101 through a servo valve drive circuit 101-3.

[0025] The controllers 101 realize the connection of synchronous signals through the synchronous input port X11 and the synchronous output port X12; and the controllers 101 are all connected to the network switch 105 through the output port X16; the network switch 105 is connected to the upper PC 106.

[0026] As Figure 2 、 Figure 3 、 Figure 4As shown in the figure, a closed-loop servo control system for a dynamic compression-shear testing machine. There are three groups of the above-mentioned controllers, namely an axial controller, a horizontal controller, and a rotation angle controller. Each group of controller 101 is connected to a servo actuator 104 that matches it. The sensors on the servo actuator 104 monitor the corresponding displacements and loads in real time from three channels: the axial direction, the horizontal direction, and the rotation angle direction, and feed back the axial displacement data and axial load data to the axial controller; the horizontal displacement data and horizontal load data to the horizontal controller; the rotation angle displacement data and rotation angle load data to the rotation angle controller. The controller 101 uses STM32F429VGT6 with an ARM architecture and externally connects an A / D chip AD7779 and a D / A conversion chip LTC1668 to establish a closed-loop PID control through the controller, the actuator, the controlled object, and the feedback system.

[0027] During the specific operation process: The controller 101 is connected to and controls the electro-hydraulic servo valve on the servo actuator 104 through the servo valve drive circuit 101-3. The servo actuator 104 is an actuator in the electro-hydraulic servo system, which converts the control signal transmitted by the controller 101 into pushing, pulling and other acting forces applied to the load, and realizes the control of the speed, direction, displacement and force of the load. A displacement sensor 104-1 and a load sensor 104-2 are provided on the servo actuator 104. They convert the collected non-electric signals into electric signals and feedback them to the controller 101 through the corresponding sensor amplification and conditioning circuits to achieve closed-loop control.

[0028] The controller 101 uses STM32F429VGT6 with an ARM architecture and externally connects an A / D chip AD7779 and a D / A conversion chip LTC1668 to establish a closed-loop PID control through the controller, the actuator, the controlled object, and the feedback system. Because STM32F429VGT6 has a fast operating speed and strong data processing ability, it can make the control system operate more effectively and stably according to the requirements.

[0029] To sum up, the axial controller, the horizontal controller, and the rotation angle controller respectively control the axial loading cylinder, the horizontal loading cylinder, and the rotation angle loading cylinder, and the three groups of controllers realize the synchronization signal connection with each other through the synchronous input port X11 and the synchronous output port X12. This is to ensure that each controller 101 obtains consistent information at the same time node, so as to avoid system instability caused by time differences. Each controller 101 is also connected to the network switch 105 at the same time and is uniformly commanded by the upper PC 106 to achieve closed-loop precise control of the loading cylinder (load), meeting the relatively demanding control requirements of the dynamic compression-shear testing machine.

[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict and without creative efforts, combine, add or delete the features in the embodiments of the present invention according to the circumstances or make other adjustments, so as to obtain different technical solutions that essentially do not depart from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A closed-loop servo control system for a dynamic compression-shear testing machine, comprising a controller (101) and a servo actuator (104), characterized in that: An electro-hydraulic servo valve, a displacement sensor (104-1), and a load sensor (104-2) are provided on the servo actuator (104). The displacement sensor (104-1) is connected to the input port X7 of the controller (101) through a displacement sensor amplification and conditioning circuit (101-1); the load sensor (104-2) is connected to the input port X14 of the controller (101) through a load sensor amplification and conditioning circuit (101-2); the electro-hydraulic servo valve is connected to the output port X18 of the controller (101) through a servo valve drive circuit (101-3).

2. The closed-loop servo control system of a dynamic compression-shear testing machine according to claim 1, characterized in that: There are three groups of the controllers (101), namely an axial controller, a horizontal controller, and a rotation angle controller. Each group of the controllers (101) is connected to a servo actuator (104) that matches it.

3. The closed-loop servo control system of a dynamic compression-shear testing machine according to claim 2, characterized in that: The three groups of the controllers (101) achieve synchronous signal connection through a synchronous input port X11 and a synchronous output port X12.

4. The closed-loop servo control system of a dynamic compression-shear testing machine according to claim 2, characterized in that: The three groups of the controllers (101) are all connected to a network switch (105) through an output port X16.

5. The closed-loop servo control system of a dynamic compression-shear testing machine according to claim 4, characterized in that: The network switch (105) is connected to an upper PC (106).

6. The closed-loop servo control system of a dynamic compression-shear testing machine according to claim 1, characterized in that: The controller (101) uses STM32F429VGT6 with an ARM architecture and externally connects an A / D chip AD7779 and a D / A conversion chip LTC1668 to establish a PID control.

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