Research On The Method And Technolgy Of GPS Based On Safety Monitoring For Construction Crane Group

In order to relieve all kinds of the energy shortage problems, it has been carrying out many large engineering projects in China. With the expansion of large engineering projects construction and the progress in science and technology, the means of safety monitoring on quality of large-scale engineering projects will go or already has gone into the development trend of modernization high-new technology of which is bound to instead the traditional technology. The research on new methods of safety monitoring on quality of large-scale engineering projects has been a focus issue of the construction sectors for a long time.The large-scale construction crane group with thecrisscross-confounding in the parochial construction plants where is high-density placed, high-strength operated, arge-weight beared and wide-range movement operated. Once the construction crane group broke down, objects-lifted falled off, collisions between the mechanisms or mechanisms and buildings, all of will bring about significant casualties and serious economic losses, and then the project construction schedules would be serious impacted. At present, the safety monitoring for running status of the construction crane group is still using traditional method of manual handing on duty. This method is lack of characteristic of real-time and automation, and safety monitoring also could not be safeguarded. In order to solve the above technical issue, considering the inherited-unique advantage of GPS technology, The method of GPS real-time precision positioning applied into safety monitoring for the large-scale construction crane group is discussed based on GPS solution in the Ph.D. thesis. It has a higher theroretical significance and application value for improving the level of modernization of the management of construction crane group. The main works and innovative results are summarized as follows:1. The research on the technology and method of real-time exchange and parallel decoding of GPS safety monitoring signalBased on the analysis of the serial port communication of GPS safety monitoring terminal (recevier), real-time transmission and multi-channel receive for GPS signal and the design and implementation of signal exchange software for both of the control center server and users, the implementation approach and the specific process of real-time security-supvision signal exchange technology via multi-channel is discussed in this thesis. The experimental test and the comparison analysis of data are shown that the feasibility and effectiveness of real-time exchange for multi-channel GPS safety monitoring signal is verified. At the same time, take a brand GPS OEM board for example, after the GPS signal data structure parsed, an approach to multi-channel GPS safety monitoring signal with real-time and parallel decoding conversion for the observation data and the navigation message is put forward based on data flow and multithreading technology, which is verified by the result of experiment analysis.2. The research and analysis of the accuracy of safety monitoring of differential GPS technologyThe algorithm of differential GPS positioning technology using single epoch data is derived in detail, and the formula of accuracy assessment is given, and the algorithm also is implemented and verified by the accuracy analysis of static and dynamic experiments using C/A code observation. Both of the precision of pseudorange differential observations and the accuracy of safety monitoring for C/A, P1and P2code are compared respectively based on DGPS process mode. The results of numerical example are shown that the precison of C/A code differential observation is slightly better than P1and P2code, and P1and P2code are almost equal. The accuracy of safety monitoring for C/A code in DGPS positioning is slightly better than P1and P2code, and H-directionis is relatively significant. C/A code is the preferred observation which is suggested in the fast algorithm of double difference interge ambiguity resolution for initial positioning using GPS single epoch data.3. The research on the fast algorithm of double-difference interger ambiguity resolution using GPS single epoch dataFirst of all, the existed several kinds of typical fast algorithm of GPS double difference interger ambiguity resolution are anlysized and the method both of DUFCOM and DC algorithm arc discussed in special. Given the satellite number tracked can reach8-10or ever more in current GPS single epoch data, DUFCOM method would be fall into the problem of low efficiency because of the number of satellites is too many, at the other side, DC algorithm has the advantages of high resolution efficiency, thus, the strategy of sorting the observation satellite is put forward, and then a novel fast combination algorithm named as FARSE is proposed. The results of example are shown that the fast algorithm could avoid the influence of the second-level satellites have on first-level satellites, which improve the efficiency for ambiguity resolution greatly, achieving real time high-sample rate GPS data processing.4. The theory and effectiveness analysis of the E_DUFCOM method and its advance On the basis of analyzing the theory of DUFCOM method to resolve GPS interge ambiguity resolution for Li phase observations using single epoch data, the DUFCOM method is expanded and derivated in this thesis, and then new methods, which are proposed to directly determine interger ambiguity resolution of L2, Ln and Lw phase observations, are named as the Extension DUFCOM methods. In connection with the existed method-DUFCOM method, EDUFCOM method is developed and the eigenvalue condition of E_DUFCOM method are given at last. The results of numerical example are shown that the efficiency of interger ambiguity resolution is the highest of (?)â–³ANn, followed by (?)â–³N1, next is (?)â–³Nw, and the lowest is (?)â–³N2in the GPS single epoch differential positioning based on the E_DUFCOM method, the reason lies in the fact that it is closely related to the constraint error. On the accuracy of positioning solution from high to low in turn are Ln, L1, L2and Lw, the reason lies in the fact that the observation noise is closely related to its itself. The comparison of four phase observations used to position, both the efficiency of interger ambiguity resolution and the accuracy of positioning, the result of Ln positioning is the optimal solution.5. The simulation design of application experiments for construction crane group collision-avoidance and warning system based on GPS solutionBased on high-precision GPS technology, wireless communication technology and computer network technology, a set of high-precision GPS construction crane group collision-avoidance and warning system (Gsertcas) is designed and developed. By the simulation design of three kinds of application experiments, the accuracy and effectiveness of safety monitoring of Gsertcas system are verified. The results of experiments are shown that whether the simulate movements between the crane mechanism and the crane mechanism, the crane mechanism and the cable mechanism or the cable mechnism and the cable mechanism,, their motion tail could be monitored with real-time by Gsertcas system in the process to be near each other (relative movement or tail after movement), and the instruction information of safe operation, C-level warning and corresponding to the instruction information, B-level warning and corresponding to the instructions information, A-level warning and corresponding to the instruction information could be displaied effectively in order to make it easy to remind the device drivers keeping safe driving, careful driving, and taking normal avoidance or emergency braking operation respectively. Under the prerequisite of the success of interger ambiguity resolution, the processing mode of SeOTF is obviously better than DGPS and smooth DGPS in the accuracy of safety monitoring. When the processing mode of SeOTF is used based on E_DUFCOM+DC fast combinatorial algorithms, the success rate of interger ambiguity resolution using GPS single epoch data up to above97%under the slightly weak interference for GPS signal, and the success rate up to above91%under the weak interference for GPS signal, however, the success rate only up to57%under the interference for GPS signal. Thus, the quality of GPS signal as much as possible should be avoided by the interference sources in the application of Gsertcas system. Gsertcas system runs steadily, timely and reliable in collision-aviodance and warning aspects, and it has good application value for the engineering construction.