Research On Real-time Remote Monitoring Technology For Roller Compaction Track Of Tunnel Asphalt Pavement

With the deepening of the development of the western region,more and more high valleys and valleys lie in front of road construction,which has become a problem that needs to be overcome in the construction of road tunnels.In order to ensure the construction quality of tunnels and roads,the detection of the degree of compaction of road rollers and the control of road rollers The real-time monitoring and feedback function of the rolling trajectory is extremely important.However,due to the particularity of the tunnel construction,the GPS signal is weak,and the traditional GPS positioning system cannot be used to accurately locate the roller in the tunnel in real time.It needs to use other positioning technologies for effective monitoring.Establishing a mathematical model of vibration compaction,combining the ZigBee positioning system,LabVIEW development environment and engineering measurements,carried out real-time remote monitoring technology of roller compaction trajectory for tunnel asphalt pavement construction.The main research contents are as follows:(1)Establish a mathematical model of the vibratory compaction system,analyze and solve the system model,and obtain the vibratory compaction circuitThe vibration acceleration of the machine has a good correlation with the stiffness of the road surface.The vibration acceleration signal collected on site is filtered and denoised,the vibration acceleration fitting period and effective value algorithm are determined,and finally the mathematical relationship expression between vibration acceleration and road compaction is obtained.(2)Based on the research of ZigBee positioning technology theory,combined with the RSSI ranging method,the ZigBee positioning technology based on the RSSI ranging method in the tunnel is analyzed and studied,and the A value and the n value of the ZigBee positioning technology are determined by the multiple linear regression method and the experimental method.According to the principle of trilateration positioning,the least square method is used to establish the position equations of the reference node and the mobile node,and the least square positioning algorithm based on the RSSI ranging method in the tunnel is obtained;CC2430/2431 is determined as the positioning system In the hardware part,IAR software is used to compile and download the program of the positioning system,complete the hardware and software design of the ZigBee positioning system,and realize the real-time display of the coordinates of the positioning node.(3)Analyzed and studied the horizontal and vertical positioning algorithms of the roller compaction trajectory,established the construction coordinate system of the roller,based on the ZigBee positioning technology and combined with engineering tests,analyzed the influence of different node numbers and different spacing distances on the positioning accuracy.The results show that: The number of reference nodes involved in the calculation increases,and the average positioning error decreases.When the number of reference points is 8,the average error tends to be stable;the horizontal and vertical separation distances are 8.5m and 5m respectively,and the 8-node 4-point dual-position dual mobile node is used for the roller Compared with using a single mobile node for positioning,the horizontal and vertical errors are reduced by 11.1% and 37.0%respectively;the curve fitting algorithm based on the least square method reduces the positioning error,compared with the dual mobile node method.For positioning,the abscissa positioning error was reduced by 13.8%,and the ordinate positioning error was reduced by 51.7%;the counting method of rolling passes was determined,the roller rolling trajectory diagram was obtained,and the real-time display and drawing of the roller rolling trajectory were completed.(4)Based on the LabVIEW virtual instrument,the overall architecture design was carried out,and the overall program block diagram of the monitoring system was developed.The high-power repeater is used to configure the receiving antenna and output antenna to realize the real-time transmission of monitoring system data in the tunnel.Combined with the Niulitang Tunnel of Guangna Expressway,the actual measurement of the project has been carried out.The results show that the average longitudinal positioning error of the roller during the second and fifth passes of the second lane are 0.14 and 0.13 m,respectively;The difference between the compaction values measured by the system for the second and fifth passes of the rolling compaction and the compaction value measured by the core-drilling sampling method is no more than 3%,which further verifies the realtime compaction trajectory of the tunnel asphalt pavement The practicability and effectiveness of the remote monitoring system.