System Simulation And Algorithm Design Of Vehicle-mounted Millimeter Wave Radar

With the rapid development of automobile industry technology,people have increasing requirements for automobile safety.Conventional driving methods are completely dependent on the driver’s judgment and will be greatly restricted in extreme environments.However,the emergence of vehiclemounted millimeter-wave radar has changed this situation.As an important sensor in advanced driver assistance systems,it has the ability to detect the environment in bad weather.Thence,it has a wide range of uses,and related technologies have become the research and development focus of major semiconductor manufacturers.As a necessary stage in the research and development process,system simulation plays an important role in reducing research costs and improving development efficiency.Effective digital signal processing algorithms,especially target tracking algorithms,are particularly important for improving radar signal processing effects.The vehicle-mounted millimeter-wave radar mainly includes two parts: a radio frequency analog end and a digital baseband end.The radio frequency analog end is used to generate and transmit FM continuous wave signals and receive echoes.The intermediate frequency signals carrying environmental information are obtained through the lower frequency.The digital baseband end is responsible for processing the IF signals to extract environmental information and feed it back to the driver to assist driving.System simulation technology based on vehicle-mounted millimeter wave radar is an analog-digital co-simulation technology for radar’s radio frequency analog circuit and digital baseband signal processing in road scenes.A reasonable and effective simulation system can not only improve research and development efficiency,but also reduce costs,and finally promote the design and production process of the radar.This article focuses on the millimeter wave radar simulation system.For the radio frequency simulation part,consider what level the simulation system should reach to ensure both the simulation efficiency and the reference value of the simulation results;for the digital baseband part,consider how to effectively construct signal processing functional modules.In order to more directly guide the hardware designer to complete the related digital circuit hardware implementation work faster;at the same time,consider how to improve the target tracking algorithm,so that the overall digital baseband can obtain optical performance.The main works include:1.Design a set of simulation system for vehicle millimeter wave radar analog radio frequency module based on Simulink,which specifically includes three parts: FM continuous wave signals generation module,transmitting module and receiving module.Through independent simulation of the radio frequency system,the reasonability and stability of the radio frequency signal processing process are verified.And the system roughly determine the circuit parameters and basic indicators of the components.2.Design a set of simulation system for vehicle-mounted millimeter-wave radar digital baseband based on Simulink,which specifically includes five functional modules: FFT,CFAR,DBSCAN,DBF and ORPF.Design the module according to the idea of hardware implement and the concept of clock beat.The internal operation logic and timing inside the modules,the data ports among the modules and the external control protocol outside the modules are fully considered when designing.Through this way,the specific workflow of the digital baseband part can be clarified.3.Aiming at the frequently occurring problems of outliers in target tracking in the application of vehicle-mounted millimeter wave radar,an outlier robust particle filter is proposed by using the multi-dimensional observation data variance weighting technique.The actual data experiment shows that the mean square error of the method proposed in this paper is 25% smaller than the traditional classical nonlinear filtering method.On this basis,the performance limit of the method in this paper is further analyzed.Finally,the filtering method has been applied to the target tracking part of the digital baseband,namely the ORPF function module for co-simulation.4.Propose a complete digital-analog co-simulation system for radar chip design to realize target detection,positioning and tracking in typical scenarios.This kind of advanced simulation,on the one hand,determines the details of the parameters and indicators of each part of the radio frequency end.On the other hand,the working process of the digital circuit is verified.Such a co-simulation system can be directly used to guide the design of radio frequency devices and the implementation of digital hardware circuits.