Research On Information Acquisition System Of Vehicle Parking Lot

With the improvement of the living standard,the number of vehicles has increased sharply,and the parking problem has become increasingly prominent.At present,the node in the system of parking detection based on wireless sensor network has the phenomenon of limited energy,unstable accuracy and uneven energy consumption.In order to improve the efficiency of parking detection system,the research mainly focuses on three parts,hardware design of wireless rechargeable parking detector,algorithm design of parking detection,and routing protocol design of wireless sensor network,the main work as follows:(1)Hardware design of wireless rechargeable parking detector.The hardware of the parking detector is divided into the sensing module,the communication module,the micro controller and the wireless charging module.The hardware chip selection and the module function are set up according to the demand of low power consumption and networking capability.The vehicle position detector node adopts the RF energy collection,which includes the optimization of the energy receiving antenna,the energy receiving circuit and the power management circuit.(2)Algorithm design of parking detection.According to the characteristics of the preprocessed data,detection algorithm can be divided into the method based on the state machine,the waveform peak and valley value and the magnetic dip angle.The calculation process of magnetic dip involves transcendental function.Because the micro controller does not have the hardware multiplier,the floating-point data cannot be calculated.The digit-by-digit and CORDIC algorithm are introduced to improve the processing ability of the micro controller to the transcendental function.The running time of the algorithm is recorded by experiments to ensure the real-time performance of the data processing.(3)Routing protocol design of wireless sensor network.The working process of AODV routing protocol is analyzed,and the coefficient of variation in statistics is introduced as the evaluation criterion of network equilibrium degree.Routing frames are modified and supplemented to generate CV-AODV routing protocols.Simulation shows that the minimum residual energy of nodes in CV-AODV has been improved,and the lifetime of nodes are prolonged.The energy balance of the network is improved.The information collection interface of the upper computer was designed with C# in VS2010,and the filtered magnetic curve can be seen in real time.In the test of communication,the data packet format is defined.The network topology software is used to complete networking test of three parking detectors.The parking detection test results show that the threshold detection algorithm based on the magnetic dip angle is better to resist the interference of adjacent parking spaces,which is suitable for areas with large parking density.