Hydraulic support electro-hydraulic control is the key technology to realize the transformation of coal mining from mechanization to automation. Hydraulic support electro-hydraulic control system has become an important symbol of advanced production technology in coal mines. With the continuous development of the hydraulic support electro-hydraulic control system, dozens of sets of hydraulic support electro-hydraulic control system are put into use every year, corresponding to the development of special hydraulic support electro-hydraulic control system software, and the reliability of the system software needs to be tested, but the current testing methods are backward and the testing efficiency is low, which can not meet the requirements of the hydraulic support electro-hydraulic control system. Requirements for the development of hydraulic control systems.
Based on this, this paper discusses the automatic detection device of hydraulic support controller.
Aiming at the problem of low test efficiency in the detection process of hydraulic support controller in coal mine, an automatic detection device for hydraulic support controller is designed. The device realizes the automatic detection of the function, performance and reliability of the hydraulic support controller, improves the detection efficiency, software adaptability and product quality of the hydraulic support controller, and plays a positive role in promoting the development of the hydraulic support electro-hydraulic control system. The bracket controller is the core component of the electro-hydraulic control system of the hydraulic bracket.
The circuit composition of the bracket controller is shown in Figure 1. The support controller mainly includes human-computer interaction unit, data acquisition unit, electromagnetic drive unit, communication unit, storage unit and power unit. Human-computer interaction unit includes keyboard, emergency stop/lock switch control, display circuit, etc. Data acquisition unit completes sensor data acquisition, and configures sensors including pressure sensor, travel sensor and inclination sensor to detect roof pressure, push stroke and attitude of hydraulic support.
The output power switching signal of the electromagnetic driving circuit controls the action of the electromagnet. The impulse current of the electromagnet is 120-180 mA, and the holding current is not less than 70 mA. The bracket controller can communicate with the left and right adjacent brackets and the remote bracket controller, thermostatic element and exchange data and information through CAN bus, RS485 and RS232. The storage unit includes a non-volatile data power-off memory, which is used to store the parameters of the bracket control program and keep it from losing after power-off. The bracket control command is sent out by the operation keyboard of the bracket controller, and the control command is sent to the bracket controller of the controlled bracket through the communication unit of the bracket controller. After receiving the bracket action control command, the bracket controller of the controlled bracket drives the bracket action cylinder pair by controlling the corresponding I/O unit state inversion. The corresponding electromagnet action converts the electrical signal into the mechanical signal of the electromagnet armature ejector stroke through the electromagnet, then controls the opening of the pilot valve, converts the mechanical signal into hydraulic signal, and then enlarges the hydraulic signal through the main valve to promote the action of the cylinder, thus realizing the action of the hydraulic support.
By compiling the application program of scaffold controller, the functions of single action control and program control of scaffold can be realized. Through the sensors installed on the hydraulic support, the state information of the action of the hydraulic support is fed back to the support controller, thus realizing the automatic control of the action of the hydraulic support. The key automatic detection device consists of bracket, pneumatic cylinder, control circuit, ejector rod, spring, probe, etc. The top rod, spring and probe constitute a key assembly. The key assembly is positioned by the bracket and locked by the nut.
The bracket also plays a supporting and guiding role for the key assembly. The other end of the bracket is fixed on the pneumatic cylinder. When the control circuit controls the extension and retraction of the piston of the pneumatic cylinder, the pressure is applied to the keyboard key through the bracket compression spring. The stroke of the cylinder is 2-15mm, and the spring force is adjusted to make the operation force of the key not less than 0.5N. The probe is made of elastic hard rubber to prevent mechanical damage to keyboard keys caused by the operating mechanism during the test. The control circuit takes ARM7 as the core.
Through programming, the control circuit can control the cylinder to extend or retract, so as to realize the automatic key-press operation of the bracket controller keyboard. Through programming, the control circuit can accurately control the key delay of the probe, realize the keyboard’s double-key interlocking control, multi-key sequential control and single-key continuous key operation to meet the operation requirements of the bracket controller. At the same time, the keyboard can be continuously operated and counted to complete the life test of the keyboard. The display unit mainly includes OLED dot matrix display and LED indicator lamp. The method of video image recognition can realize the automatic detection of the display unit.
The OLED display array pixels are all lit up or all closed by the test program.
Through the comparison of video image recognition, we can determine whether OLED has pixel damage or not; through the gray recognition of the image, we can determine whether its brightness meets the technical requirements of the display. The working state and brightness of LED indicator lamp can be determined by using video image recognition method through compiling the test program of running horse lamp. Sensor input signal includes digital signal and analog signal, analog signal is input by D/A circuit, and digital signal is input by interface circuits such as CAN bus and RS232. The standard signal source circuit is constructed in the detection device, and the signal collected by the bracket controller is compared with the standard signal to determine whether the sampling accuracy and sampling speed of the sensor acquisition circuit of the bracket controller meet the technical requirements. In addition, it can also simulate the field environment, realize active business monitoring, identify whether the support controller software meets the requirements under different working conditions through the field operation sensor data, store the pressure, travel and inclination sensor data in the form of database on the computer, and save the number of sensors through the RS485 interface of the computer. It is downloaded to the detection device. When detecting the automatic control function of the support controller, when the support moves, the corresponding sensor data is automatically checked, and the sensor data is transmitted to the corresponding port of the support controller through analog D/A channel or digital transmission channel. This function can be checked when the roof is broken and the floor is soft at the working face. Whether the response measures of the support controller software are effective or not, the adaptability of the support controller software to the field environment is judged. The output of the electromagnetic driving unit is power type, and the load is electromagnet. It is a 3000-4000 turn inductive load with resistance of 100-120_. The rated voltage of the electromagnet is 12V, the rated current is 120-180 mA, and the load power is 2-3W. The electromagnetic driving circuit analog detection system is shown in Figure 2.
The detection device uses 100/3W resistance and inductance coil as analog load, and constructs a bypass detection circuit.
The high precision resistance is used to detect the load current of the driving circuit, and the load driving ability of the driving circuit is tested. Through the test program, the specified electromagnetic driving instructions are sent to the detection device. The detection device reads the corresponding electromagnetic driving detection unit, determines whether the electromagnetic driving port circuit is correct, and tests the electromagnetic driving ability of the bracket controller. In addition, the life test of driving circuit can be carried out by compiling test program and cyclic driving counting to test whether the dissipated power of power devices meets the reliability requirements of the system. The communication detection circuit is built between the support controllers to listen for the communication signals between the support controllers. The transmission signal, received signal and intercepted signal of the support controllers are compared. The packet loss rate, transmission delay, maximum load carrying capacity and the load and duty cycle of the communication link under normal working conditions are compared. The real-time performance and reliability of data transmitted by communication circuit are tested and evaluated. The scaffold controller automatic detection device is used to integrate the test system with the test system, digitalize and process the test cases, and integrate them into the whole test process. It solves the problem that manual operation can not test the adaptability of the scaffold controller software to the field environment. The application of automatic detection device for scaffold controller not only improves the testing efficiency of scaffold controller and its software, but also improves the testing quality of scaffold controller products.
The potential design problems of products can be found through the analysis of large data of test data.