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Research On Control Strategies Of Vehicle Anti-Lock Brake System And Vehicle Braking Stability Based On Simulation

Posted on:2006-05-07Degree:DoctorType:Dissertation
Country:ChinaCandidate:G Y TangFull Text:PDF
GTID:1102360182469267Subject:Mechanical Manufacturing and Automation
Abstract/Summary:PDF Full Text Request
As an effective approach to improve security of vehicles,ABS(Anti-lock Brake System) has been studied world-widely for a long time. It has most important significance to develop ABS products with intellectual property of China. Now the study and improvement in the field is still in progress in world, and most of researches are focused on the control strategy. In this dissertation, several new control approach are adopted to deal with ABS control problems and stability of a vehicle with ABS. On the basis of analysis of forces acting on the vehicle, a vehicle dynamic model is built, which is realized with Matlab/Simulink. The control methods of ABS such as logic threshold control and sliding mode control are analyzed . As a switch control , the chatter of system can be induced by sliding mode control, which can influence performance of system. Then the cause of chattering is analyzed and fuzzy sliding mode control method is presented , the fuzzy control rule is simplified by the second layer of sliding mode. The simulation of single wheel vehicle show that the presented control method can shorten the response time and the chatter is restrained. A GA(Genetic Algorithm) based on-line parameter design method of ABS PID controller is proposed. The operator of GA is improved to enhance its effectiveness. Then the parameters of PID controller can be adjusted on line and the ABS can adapt the circumstance well. Simulation demonstrates that the presented method can restrain the overshoot and adapt work condition well. A simplified vehicle model and the state space equation are built, and stability control approach of braking vehicle on splitter road is presented on the basis of optimal control. Through adjusting the slip ratio of wheels ,the brake force of wheels and corresponding yaw torque of vehicle can be adjusted . Simulation shows that the stability of vehicle can be hold well by the presented method on splitter road. To deal with stability problem of a vehicle combined steering and braking, its dynamics is analyzed. To establish model of the vehicle, a T-S fuzzy model and its identification algorithm are developed based on fuzzy neuro network. The network which inputs and outputs are composed of several layers of forward structure is utilized to build the structure and premise parameters of T-S fuzzy model through learning from the training data. In this way, the vehicle dynamic system is divided into many linear sub-systems, and the system output is weighted-sum of these sub-systems'outputs. A CARIMA model can be derived from the developed fuzzy model, and generalized predictive control(GPC) is applied to solve the control problem of vehicle stability. A maneuvers combined braking and steering is simulated , the results show that fuzzy model based generalized predictive control can be applied to improve stability of the vehicle effectively. Based on object-oriented technology, the crucial problems of simulation and the structure of vehicle dynamics simulation system are analyzed . The class scheme of system is built . The method to set up use case and interaction diagram is given. Software is developed ,which has the advantages of distinct structure and easily to expand and maintain .
Keywords/Search Tags:Anti-lock Brake System(ABS), Vehicle Dynamics, PID Control, Variable-Structure Control with Slide Mode, Fuzzy Neuro Network, Simulation
PDF Full Text Request
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