Research On Full Speed Range Adaptive Cruise Control

ACC can effectively reduce the driver's burden and improve driving safety.It can also alleviate the traffic congestion caused by the increasing car parc.The practicality of the ACC system is reflected in the coverage of the vehicle speed range on the one hand and the user's acceptance of the system on the other.In recent years,scholars and manufacturers pay more attention on the research of improving the humanization of the ACC system.From the engineering point of view,this paper studies the ACC control method that can cover the full speed range while considering efficiency,safety,comfort and fuel economy refer to the BSISO 15622:2018,a kind of design standard for ACC system.The main research contents are as follows:Firstly,this paper analyzes the functional requirements of the ACC system.The system is divided into decision-making layer and control layer according to the control process in the framework of hierarchical control and the stability of the system and the difficulty of adjusting the control parameters.A sensor data processing method for efficient follow-up target filtering is designed in the meanwhile.Then,the acceleration factor of the preceding vehicle is brought into the calculation of the time-gap after analyzing its influence of the following distance.This makes the established clearance strategy is more in line with the driving characteristics and has a faster response,which effectively improves traffic efficiency.According to the driving state equation,use the MPC method to design the following model which can output the expected acceleration under the consideration of traffic efficiency,driving safety,comfort and fuel economy.And complete the design of the cruise control part on the basis.The state machine model is established to make a more detailed division of the following mode and cruise mode.The desired acceleration is optimized in the form of constraints while judging the driving state by the state machine.All of these complete the design of the decision-making layer.Based on the vehicle driving equation and the parameters,the driving/braking torque calculation model,the engine inverse model,the transmission model,the brake inverse model and the switching strategy of throttle and brake are constructed.Furthermore,complete the design of the control layer.In order to adjusting the parameter of controller in a Real-Time environment,a variety of acceleration excitation signals are built.As a result,the control layer model can accurately respond to the desired acceleration.Finally,the driving process was divided into single operating conditions,and several test conditions which covering the range of 0-120 km and all single operating conditions were designed.Test and verify the functionality of the whole control model and multi-target control effects in the form of co-simulation which integrate SCANeR,veDYNA and Simulink.Generate code of the control mode and verify its stability by a RT-test platform which is based on a Real-Time system integrates SCANeR,veDYNA.The result of test show that the control method from this paper can take multiple control targets into account to get good control effects.And the method of testing with Real-Time system also has certain reference value for the development of ACC system.