Research Of Virtual Detection Platform For Hook-lift Mechanism Of Garbage Truck Based On LabVIEW

In recent years, with our government have paid more and more attention to sanitation, the hook-lift garbage truck which can both dump waste and load or unload container has been the research hot spot. The hook-lift mechanism structure is the core part of garbage truck. Then, in order to ensure its reliability and stability, the operation status needs to be monitored. Traditional detection equipment has shortcomings of big size, fixed function, high cost and long update cycle of technology. In a word, it cannot meet the need of modern technology development. Virtual instrument technology proposed by American National Instrument Company can make the instrument as software and add users define function which makes it flexibility. Besides, it has short update cycle, low cost and the broad scope of application.Aiming to the hook-lift, basing on the design of hardware and virtual instrument software technology, a virtual detecting platform of hook-lift is developed. And the hardware and software systems are debugged. The specific contents include the following aspects:Firstly, the hardware system of detecting platform for hook-lift structure is developed. Hardware system is used to collect, transform and transmit signals. It consists of sensors, signal conditioning circuit and DAQ card. According to the work principle of hook-lift structure, the two strokes and pressure of hydraulic cylinder are detected. Then, the measured signals are converted to standard voltage signal through the sensor and signal conditioning circuit. The simulation signals are translated into data signals with DAQ card. Considering the cost, the USB-mini DAQ is used. The main function module of its is A/D conversion module, MCU control circuit and USB communication interface. The embedded chip of PIC16F877 not only has the general function of microcontroller, but also has embedded the ADC module with 10-bit 8-channel. And, the form of USB interface is used to communicate with the host computer. It can guarantee the transmission efficiency, plug and play data acquisition card.Secondly, the software system of detecting platform of hook-lift is developed basing on virtual instrument. Software system is used to deal with the digital signals and display them. Under the powerful function of LabVIEW, procedure is written with the idea of modular design. The software system consists of five modules, such as data acquisition, signal pre-processing, data managing, time-domain analyzing and result display. Module programs are prepared in the program block diagram. The detection system is operated with entry control which is in the front panel. Furthermore, the results which have been processed are displayed in the front panel.Finally, the detecting platform of hook-lift based on virtual instrument is debugged. With serial debugging assistant, the communication between data acquisition card and computer is testified as normal and stable. The simulation signals created by circuit are collected and displayed in the front panel. Then, the LabVIEW software system is debugged. According to the results of function module playing, the feasibility and reliability of the detecting platform is verified.The detection platform of hook-lift based on virtual instrument has the advantages of simple interface, easily-operated and strong extendibility. Meanwhile, the data acquisition card is simple, compact, powerful and easily taken. The platform can be applied in teaching, researching and engineering.