| At present, passenger car mainly depends on the hydraulic power assisted to carry out frictional brake. This brake style has several problem as follows:the brake performance will decrease or even failure, which caused by the heat recession under long-time brake; the brake performance will be bad-response because of the braking medium inertial and the complex braking pipelines; the rapidly development of the electrical technology makes every kinds of the controlling function integration (such as ABS\TCS\ESP\ACC\EBD) to the intelligent brake more easier, but caused matching deviation appeared between the bad-response traditional hydraulic brake mechanism and high speed electronic control unit.In order to solve the problem that traditional hydraulic brake system has, contactless electromagnetic braking system as a kind of braking style can be provided no doute, this braking style hasn’t been equipped with frictional brake, it’s reaction rate is more rapid than the frictional brake’s, and integrated control is more simple, the effect of brake torque on the electromagnetic braking system is better than the frictional brake’s. However, the simple electromagnetic braking system also exist disadvantage, such as maximum excitation current is needed as vehicle brakes, lack of failure safety controlled function. Anti-interference ability of the pure electromagnetic braking system can not assure the braking system safely completely. Additional equipped with large capacity and high voltage batteries increase the vehicle loading and so on.To make full use of the merits of the hydraulic brake and electromagnetic brake, and overcome their disadvantage, the assumption that developing the electromagnetic-hydraulic hybrid braking system is proposed by some experts, which is compounded by the electromagnetic braking system and the hydraulic braking system. This dissertation proposes the new orientation to the "Anti-lock Brake Controlling Technology Research on Electromagnetic-hydraulic hybrid Braking System" after having fully investigated and analyzed the research development of the electromagnetic-hydraulic hybrid braking system. Based on this, the research work has been carried out as follows:First, research achievement and development of the electromagnetic-hydraulic hybrid braking system at home and aboard is analyzed, summarizing the innovative point, main achievement and the disadvantage of those current research material, analyzing the development trend and the key technology of the electromagnetic-hydraulic hybrid braking system, which lays solid foundations for further study.Secondly, the braking system and the wheel parameters of the Jetta car is chosen as the research object, system design and theory analysis to the electromagnetic-hydraulic hybrid braking system are carried out, design rules and scheme were determined. To solve the problem of the heat recession and heat failure of the hybrid braking system completely, the structure form that the electromagnetic braking system and the hydraulic braking system share a hybrid brake disc is proposed creatively, it’s working theory and design merit are illustrated in detail.The mathematical model of the hydraulic brake and electromagnetic brake is established based on the structure form of the hybrid braking system.In order to promote the recognition ability of the electromagnetic-hydraulic hybrid braking system to the complex road condition, the research of the road electromagnetic real-time estimation and controll strategy is carried out based on it’s merits,such as brake convenient and reliable, reaction rapidly, high control precision. According to the characteristic curve of the electromagnetic braking torque and vehicle speed, research word which including determination of the critical velocity, modeling separately, experimental revision and vehicle dynamic analysize are carried out. Applying the software Matlab and Lab VIEW, compiling the program of road recognition electromagnetic real-time observation and estimation, the precision recognition ability of the hybrid braking system’s control unit to the road condition is realizing.According to the established mathematical model, the sliding mode variable structure control theory is applied, the sliding surface of the hybrid braking system is defined. According to import tracking error integral term to switching function, the sliding mode variable structure control unit based on the controlling target of optimal slips ratio, which improves the tracking precision. Simulating the asphalt pavement and snow-ice pavement, the performance compared simulated analysis experiment to the hybrid braking system between the traditional hydraulic braking system and electromagnetic-hydraulic hybrid braking system is carried out, which proves that the system can improve the stability of the vehicle braking system, reduce the braking distant and shorten the braking time.Finally, considering the electromagnetic-hydraulic hybrid braking system is a multidisciplinary complex non-linear system, the factors that affect its performance is very complex. In order to reduce it’s developing cost, improve research efficiency and quality, the dissertation establishes the hardware-in-loop simulation platform, the hardware-in-loop anti-lock braking control technology research of the hybrid braking system is carried out in different road condition, the control strategy is modified according to the experiment results.The dissertation creative points are:1. In order to overcome the shortcoming such as slow reaction rate of hybrid anti-lock brake system, friction and wear, heat recession etc., on the base of summarizing and analyzing the research development of the electromagnetic-hydraulic hybrid braking system at home and aboard, proposes a research direction of electromagnetic-hydraulic brake anti-lock controlled technology in the field of gasoline vehicle and hybrid electric vehicle, which includes eddy current brake and hybrid brake.(The braking mode is different from electric vehicle braking mode applying motor brake and hybrid brake). Meanwhile, the jetta’s brake system and its tyre parameters is chosen as research object, composite brake system research theory is established (such as design rule and scheme, working principle and parameter, mathematical model etc.).2. Aiming at the composite brake system’s structure form current disadvantages, such as larger structure dimensions, low integrated level, heat failure and so on, the structure design scheme is proposed, which the electromagnetic brake and hybrid brake share a composite brake disc. The scheme makes the composite brake system’s structure more compactable and high integrated level. Meanwhile, the requirement to the brake disc material of the electromagnetic brake and the hybrid brake is met. As the brake torque improving, the hidden trouble of heat failure decreases effectively.3. In the electromagnetic-hydraulic hybrid braking system, the article proposes a new idea that applying the electric brake torque to modulate vehicle ABS and achieve the aim of anti-lock brake controlled. A siding mode controlling strategy for hybrid braking system is developed. At the process of controlling, the research of the road real-time estimation and estimation algorithm is carried out based on it’s merits,such as brake convenient and reliable, reaction rapidly, high control precision. With compiling the program of road recognition electromagnetic real-time observation and estimation, the ABS controlling program and road electromagnetic estimation program can work together perfectly, the performance of the composite brake system in several kinds of road is improved.4. Base on the concrete vehicle brake system parameters, the prototype of the electromagnetic-hydraulic hybrid braking system is designed, the hardware-in-loop simulation platform is established. the contrast test between the traditional hybrid brake system and the electromagnetic-hydraulic hybrid braking system is carried out. Design scheme of the hybrid braking system is continuous improved according to the hardware-in-loop simulated experiment research in multiple road condition. And also, it established a base for real car experiment. |
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