Research On Data-Acquiring System Of The Engineering Vehicles

As modern engineering moves fast, the engineering vehicles are wide in use, frequently employed, so that its position gets higher. In order to know the working stat of heavy vehicles accurately, the dissertation gave a data-accquiring system equipped for the engineering vehicles.The system can monitor the state and parameters of the key parts on vehicles, record the data of signals sampled. The users can check the state of the tested parts at any time.The design of the system could provide the theoretical support numerically, discover the potential risks, and prevent incidents significantly.The author consulted plenty of the related products specifications and documents of countries, thereafter put the blueprint of the system, including signal source to sample, the hardware architecture of the master node and data sampling nodes (refered as slave nodes in the following). The nodes could■transfer and receive data via RS485 bus. The general index and application field of this system was also mentioned.Slave nodes was connected to vehicle's sensors or transmitters, could sample and convert to digital values through conditioning circuits of two current input signals, two voltage input signals, a pulse signal and tempertature signal. Slave node could receive command codes from master node and transfer signal data to master node via RS485 bus.On the platform of multitask operation systemμC/OS- II, Users control the master node by pressing keys, give orders to master node to display the contents of selected slave node or to save the data of all slave nodes to flash disk by the file system of FAT16.The dissertation finished the design of hardware, software, specific items listed as followings:Of hardware, the function of the master node and slave node was confirmed.Plans, circuits of which sampling conditioning circuits especially were illustrated and simulated by software. The schematics and PCB files were brought out. The solution selection and interface circuits of LCD, data store, RS485 were made.Of software, programme project was designed, flow charts of every module were drawn, error budgets calculated on slave node.Tranplantation ofμC/OS- II to LPC2119 was completed, application tasks were created based on the software development mode of multitask realtime operation sysem, and a set of RS485 protocol defined.On the last stage, test circuits were built to debug the system with the software Serial Port Assistant. Rightness of design was verified, the paper summarized, the work briefed, the feature and significance explained.Meanwhile the flaws and improvement was pointed to pave the way for further study of the subject.