CN104536316B - Multichannel servo-control system for automobile component fatigue test - Google Patents

Abstract

The invention discloses a multi-channel servo control system for fatigue test of automobile parts, which comprises an input circuit, a processor, a PID controller, a comparator, a power amplifier circuit, a servo valve, a hydraulic cylinder, a displacement sensor and a pressure sensor; a PID The controller calculates the pressure signal received from the pressure sensor and the voltage signal output by the processor to obtain a difference, the displacement signal detected by the displacement sensor is transmitted to the comparator, the difference output by the PID controller and the displacement signal detected by the displacement sensor After the comparator is transmitted to the power amplifier circuit, the load is electrically connected to the sensor used to collect the load deformation, the sensor used to collect the load deformation transmits the collected signal to the PC, and the signal conditioning is set between the sensor used to collect the load deformation and the PC circuit, a data acquisition card is inserted into the PC, and a front-end interface circuit is set on the signal conditioning circuit. The purpose of improving system immunity, interconnection and coordination is achieved.

Description

Multi-channel Servo Control System for Fatigue Testing of Automobile Components

technical field

The invention relates to a multi-channel servo control system for fatigue test of automobile parts.

Background technique

As the most important means of transportation in contemporary society, automobiles undertake the important task of transportation in daily life. As the most commonly used means of transportation, it has relatively high requirements on production volume, and mass production is an essential attribute. At the same time, as one of the high-tech living utensils, the application of new materials and technologies is also very common. At the same time, in order to meet the effective and reasonable utilization of new materials and technologies, the production process of automobiles integrates the top technology of many industries including machinery, chemical industry, electronics, metallurgy, etc., which embodies the latest technological innovation and material innovation of human beings. results.

A car is composed of tens of thousands of parts, and each part, such as suspension, rear axle, and sub-frame, needs to be designed and researched reasonably, and then it needs to be tested to judge whether it is qualified or not. These tests include static load , dynamic load and fatigue tests, etc. During the running of the car, the periodic rotation of the wheels will have a periodic impact on the load parts of the vehicle during operation. This periodic load is also called a cyclic load. Auto parts cannot maintain a stable working state for a long time under cyclic loading conditions. This negative effect causes the working stress of parts, such as vehicle suspension, rear axle and sub-frame, to be lower than the yield strength of the materials used to manufacture parts. Since most vehicles have a long service life, auto parts under the action of cyclic stress There will be failure phenomenon, which is commonly referred to as fatigue damage. The fatigue failure of most mechanical parts occurs earlier. Data show that fatigue fracture is the most important form of component failure. Especially today, with the development of large-scale mechanical equipment, the working environment of high pressure and heavy load tends to be common. Parts will generate high temperature and corrosion during high-speed operation, and fatigue damage will follow. Existing testing machines are divided into static testing machines and dynamic testing machines. Static testing machines can conduct tests by themselves after setting the test indicators; dynamic testing machines can also complete tests, but they are weak in test spontaneity. But both the static testing machine and the dynamic testing machine have the problems of immunity, poor interconnection and coordination.

Contents of the invention

The object of the present invention is to propose a multi-channel servo control system for fatigue testing of automobile components to achieve the advantages of improving system immunity, interconnection and coordination in view of the above problems.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A multi-channel servo control system for fatigue testing of automobile components, including an input circuit, a processor, a PID controller, a comparator, a power amplifier circuit, a servo valve, a hydraulic cylinder, a displacement sensor and a pressure sensor, and an output terminal of the input circuit It is connected with the input end of the processor, the output end of the processor is connected with the input end of the PID controller, the output end of the PID controller is connected with the input end of the comparator, and the output end of the comparator is connected with the input end of the power amplifier circuit connection, the output end of the power amplification circuit is connected to the input end of the servo valve, the servo valve controls the action of the hydraulic cylinder, the hydraulic cylinder drives the load to deform, the displacement sensor detects the hydraulic displacement of the hydraulic cylinder, and the pressure sensor detects the load The pressure signal received is detected, and the pressure sensor transmits the detected pressure signal to the PID controller, and the PID controller calculates the pressure signal received from the pressure sensor and the voltage signal output by the processor to obtain a difference, The displacement signal detected by the displacement sensor is transmitted to the comparator, the difference output by the PID controller and the displacement signal detected by the displacement sensor are transmitted to the power amplifier circuit after the comparator, and the load is electrically connected to the sensor for collecting load deformation The sensor for collecting load deformation transmits the collected signal to a PC, and LabVIEW simulation software is set in the PC to simulate the signal collected by the sensor for collecting load deformation; the sensor for collecting load deformation is connected to the PC A signal conditioning circuit is set between the signal conditioning circuit, and the signal conditioning circuit amplifies, isolates or filters the received signal of the sensor for collecting load deformation, and a data acquisition card is set between the signal conditioning circuit and the PC, and the data acquisition card will receive The analog signal of the signal conditioning circuit is converted into a binary digital signal, and the data acquisition card is inserted on the PC; a front-end interface circuit is set on the signal conditioning circuit, and the front-end interface circuit includes piezoresistor R1, precision resistor R2, Resistor R3, capacitor C1 and transient voltage suppression diode D1, the varistor R1, precision resistor R2 and capacitor C1 are all connected in parallel at both ends of the transient voltage suppression diode D1, and the resistor R3 is connected in series with the precision resistor R2 and capacitor Between C1.

The technical solution of the present invention has the following beneficial effects:

The technical scheme of the present invention integrates three technologies of mechanical, electrical and hydraulic, and adopts high technologies such as closed-loop control and electromechanical integration, thereby achieving the purpose of improving the system's anti-disturbance, interconnection and coordination.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the functional block diagram of the multi-channel servo control system for the fatigue test of automobile parts described in the embodiment of the present invention;

FIG. 2 is an electronic circuit diagram of the front-end interface circuit according to the embodiment of the present invention.

detailed description

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

As shown in Fig. 1, a multi-channel servo control system for fatigue testing of auto parts, including input circuit, processor, PID controller, comparator, power amplifier circuit, servo valve, hydraulic cylinder, displacement sensor and pressure sensor , the output of the input circuit is connected to the input of the processor, the output of the processor is connected to the input of the PID controller, the output of the PID controller is connected to the input of the comparator, and the output of the comparator is connected to the power amplifier The input end of the circuit is connected, the output end of the power amplifier circuit is connected to the input end of the servo valve, the servo valve controls the action of the hydraulic cylinder, the hydraulic cylinder drives the load to deform, the displacement sensor detects the hydraulic displacement of the hydraulic cylinder, and the pressure sensor detects the load. The pressure signal is detected, and the pressure sensor transmits the detected pressure signal to the PID controller. The PID controller calculates the pressure signal received from the pressure sensor and the voltage signal output by the processor to obtain a difference, and the displacement signal detected by the displacement sensor Transmission to the comparator, the difference output by the PID controller and the displacement signal detected by the displacement sensor are transmitted to the power amplifier circuit after the comparator, the load is electrically connected to the sensor used to collect the load deformation, and the sensor used to collect the load deformation will collect The signal is transmitted to the PC, and the LabVIEW simulation software is set in the PC to simulate the signal collected by the sensor used to collect the load deformation, and a signal conditioning circuit is set between the sensor used to collect the load deformation and the PC, and the signal conditioning circuit is used for receiving The signal of the load deformation sensor is collected and amplified, isolated or filtered. A data acquisition card is set between the signal conditioning circuit and the PC. The data acquisition card converts the received analog signal of the signal conditioning circuit into a binary digital signal, and the data acquisition card Plugged into the PC.

The front-end interface circuit is set on the signal conditioning circuit, and the front-end interface circuit is shown in Figure 2, including varistor R1, precision resistor R2, resistor R3, capacitor C1 and transient voltage suppression diode D1, varistor R1, precision resistor Both R2 and capacitor C1 are connected in parallel at both ends of transient voltage suppression diode D1, and resistor R3 is connected in series between precision resistor R2 and capacitor C1.

After the difference is input to the position comparator, the expansion and contraction of the hydraulic cylinder rod can be changed, that is, the load deformation can be changed, thereby changing the loaded pressure value.

The load is the component to be tested for fatigue testing. Through the repeated pressure test of the components by the hydraulic cylinder, and by collecting the data of the load deformation, the fatigue test of the components is realized.

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still The technical solutions recorded in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (1)

1. A multi-channel servo control system for auto parts fatigue test, is characterized in that, comprises input circuit, processor, PID controller, comparator, power amplification circuit, servo valve, hydraulic cylinder, displacement sensor and pressure sensor , the output end of the input circuit is connected with the input end of the processor, the output end of the processor is connected with the input end of the PID controller, the output end of the PID controller is connected with the input end of the comparator, and the output end of the comparator is connected with the input end of the comparator The input end of the power amplification circuit is connected, the output end of the power amplification circuit is connected with the input end of the servo valve, the servo valve controls the action of the hydraulic cylinder, the hydraulic cylinder drives the load to deform, and the displacement sensor detects the hydraulic displacement of the hydraulic cylinder. The pressure sensor detects the pressure signal received by the load, and the pressure sensor transmits the detected pressure signal to the PID controller, and the PID controller calculates the pressure signal received from the pressure sensor and the voltage signal output by the processor Finally, a difference is obtained, and the displacement signal detected by the displacement sensor is transmitted to the comparator, and the difference value output by the PID controller and the displacement signal detected by the displacement sensor are transmitted to the power amplifier circuit after the comparator; the load is used for collecting The sensor of load deformation is electrically connected, and the sensor for collecting load deformation transmits the collected signal to PC, and LabVIEW simulation software is set in the PC to simulate the signal collected by the sensor for collecting load deformation; A signal conditioning circuit is set between the sensor of the load deformation and the PC, and the signal conditioning circuit amplifies, isolates or filters the received signal of the sensor for collecting the load deformation; a data acquisition card is set between the signal conditioning circuit and the PC, The data acquisition card converts the received analog signal of the signal conditioning circuit into a binary digital signal, and the data acquisition card is inserted into the PC, and the signal conditioning circuit is provided with a front-end interface circuit, which includes a pressure-sensitive Resistor R1, precision resistor R2, resistor R3, capacitor C1 and transient voltage suppression diode D1, the varistor R1 and precision resistor R2 are connected in parallel, capacitor C1 is connected in parallel with transient voltage suppression diode D1, one end of the precision resistor R2 and the capacitor A resistor R3 is connected in series between one end of C1, and the other end of the precision resistor R2 and the other end of the capacitor C1 are both connected to the varistor R1 and the transient voltage suppression diode D1; After the difference is input to the comparator, it changes the expansion and contraction of the hydraulic cylinder rod, that is, changes the load deformation, thereby changing the loaded pressure value; The load is the component to be tested for the fatigue test. The component fatigue test is realized by repeatedly testing the component through the hydraulic cylinder and collecting the data of the load deformation.