Font Size: a A A

Research On Electronic Stability Coordinated Control System For Double-axle Vehicles

Posted on:2009-11-28Degree:DoctorType:Dissertation
Country:ChinaCandidate:J H GuoFull Text:PDF
GTID:1102360245963431Subject:Vehicle Engineering
Abstract/Summary:PDF Full Text Request
Variable chassis electronic control systems have been applied on vehicles for improved driven safety. But multiple control systems also result in more and more couplings and conflicts between the subsystems each other. In other to resolve the problem, the vehicle electronic stability coordinate control system, which adding a coordinate controller based on the subsystems, was put forward, and the sorts of conflicts integrated chassis control system are resolved.All the work of the thesis is supported by the state fund project—study on control strategy of vehicle driving active safety on wet and slip road. Based on the existing research achievements, the logics related to vehicle coordinate control stability and system development for a double-axle light-duty vehicle is performed. The problem of coordinate control is discussed systemically including coordinate controls between AFS, VTD, ESP and SAS. The coordinate control algorithm about the above coordinate control problems is analyzed and off-line simulation and hardware in loop test are done.(1)Regarding the double-axle light-duty vehicle as the research object, the nonlinear 15-DOF vehicle dynamics models were established. Vehicle models include: engine model, transmission model, wheel kinematics model, tire model, whole vehicle model, driver model, and assist calculate model etc. The vehicle dynamics models can simulate 4W steering vehicle, and satisfy the simulation request of braking, steering and accelerating. With prescaning neural network driver model, closed loop control simulation of double lanes input for the driver can be performed. (2)Regarding a double-axle light-duty vehicle as the research object, a double-axle vehicle coordinate control system is designed. The whole structure and the work principle of coordinate control system are put forward. with module design method, coordinate controller structure and control processes are presented and control procedures and coordinate control algorithms are built respectively according to different vehicle running cycle.(3)The AFS controlling logic is set up based on fuzzy control; variable torque distribution(VTD)controlling logic based on LQG, ESP algorithm and torque distribution strategy are discussed, SAS controlling logic is discussed also . The simulation results show that the subsystems set up above can accomplish the target of controlling very well, enhancing the vehicle stability and safety performance. And with the simulation analysis, various work characteristic and work range adapted are concluded which can provide the basis of coordinate control logic.(4)With the combination of VTD and ESP, the coordinate control logic based onβ?βmethod is put forward. The parameters of the coordinate control are optimized with genetic algorithm, thus a new DYC control system is formed and simulation test of DYC coordinate control performance are performed based on the many driving cycles such as single lane input and double lanes inputs. The results show that DYC can solve the conflict of VTD and ESP control targets, and each subsystem can work in their control territory stably. At the same time DYC comprehensive control performance is better than the single control and vehicle handle and stability are improved.(5)With the combination of AFS and DYC, the coordinate control logic is put forward based onβ?βmethod and The parameters optimization with genetic algorithm. Simulation test and performance analysis of AFS and DYC coordinate control are performed based on the many driving cycles. The results show that coordinate control equipment can solve the conflict of torque distribution among each subsystem and each subsystem can fully exert their own function in their control territory. With the vehicle stability kept, the coordinate control can enhance vehicle speed; reduce the effect on the driver and increase vehicle handle and stability and the enjoyment of driving. (6)the coordinate control algorithm between SAS and AFS_DYC coordinate control system are studied and simulated. The final coordinate control algorithm for double-axle vehicle is performed. The simulation results show that the algorithm can identify the vehicle states and coordinate control all electricity control subsystem. The conflicts between all subsystems are resolved. The vehicle stability enhance mostly.(7)hardware in the loop test of AFS and ESP coordinate control is done based on the HIL test platform,and the characteristic analysis is carried out. The test results show that the coordinate control algorithm designed in this paper can satisfy the need of real time, and has good adaptability, so the algorithm can be used in the development of the coordinate control ECU.Through study on coordinate control logic and hardware in loop test, conclusions can be got as follows:(1)The electronic stability coordinate control system for the double-axle vehicle designed in the paper can resolve the control conflicts of the chassis electric control systems in integration process. And with the module design, the design of chassis electricity control systems becomes more flexible that satisfies the development need of vehicle active safety system.(2)AFS and DYC coordinate control logic based onβ?βmethod can distinguish the running states of vehicle exactly. Through distributing coordinate control parameter of work time order and efficiency for each subsystem, the conflict of AFS and DYC control can be resolved during steering, that is propitious to advance vehicle handling and steering and safety.(3)The vehicle coordinate control algorithm can identify the vehicle states and coordinate control all electricity control subsystem. The conflicts between all subsystems are resolved. The vehicle stability enhances mostly.(4)The hardware in loop test results show that the coordinate control logic based onβ?βmethod has good performances of real time and adaptability, and it can be used in chassis electric control system development which validates its practicability.
Keywords/Search Tags:vehicle engineering, double-axle vehicle, stability control, coordinated control, hardware in loop
PDF Full Text Request
Related items