Design Of Self-powered Wireless Weigh-in-motion Sensor Node Based On Piezoelectric Effect

Transportation is involved in the cultural and economic development of various places,is the national development of the basic industry,but at the same time also breeds a lot of overloading phenomenon.Weigh-In-Motion as the way to control this phenomenon has been developed for decades,but still there is a high cost,difficult installation and maintenance,wiring project trival,such problems as serious damage the pavement structure,in view of the above problem,by comparing the material selection,design of miniaturization,the methods of wireless data transmission,piezoelectric energy collection address the above shortcomings,A self-powered wireless Weigh-In-Motion sensor node based on piezoelectric effect is designed.The specific research contents are as follows:(1)By comprehensively analyzing the research status of Weigh-In-Motion of pavement and piezoelectric energy harvesting at home and abroad,the overall framework and design key points of sensor nodes are determined,and the piezoelectric effect and weighing principle are described.(2)By comparing and selecting various piezoelectric materials,piezoelectric ceramics and structural configurations,the structure of piezoelectric sensing unit is finally determined as three PZT-5H piezoelectric ceramics stack connected in parallel.Then,the static stress and strain simulation is carried out by workbench software.Finally,the package design of multiple piezoelectric sensing units is carried out.(3)The design of the wireless weighing sensor module is subdivided into three modules: signal acquisition,core processing and data transmission.The main hardware and related circuits of these three modules are studied and designed respectively,and the physical circuit board is made,and then the relevant wireless transmission experiment is done with the physical matching universal testing machine.(4)The characteristics of piezoelectric power generation are analyzed as high voltage and unstable AC.LTC3588-1 with rectifier and step-down function is selected as the energy harvesting circuit and lithium iron phosphate battery as the energy storage element.Then the universal testing machine is used to apply increasing load to the sensor node to test the piezoelectric performance and the practicability of LTC3588-1 energy harvesting circuit.Under the same assumption,the power consumption of electronic components and the collected energy of LTC3588-1 are analyzed and calculated,and the calculation result shows that the latter is larger,which proves the rationality of self-power supply.