外文翻译----非线性pid控制在一系列卡车abs问题中的应用(编辑修改稿)

外文翻译----非线性pid控制在一系列卡车abs问题中的应用(编辑修改稿)内容摘要：

ars. Current Technology Various control strategies have been implemented in real ABS products or discussed in publications. Since the technologies used in mercial ABS products are usually kept as trade secrets, it is very difficult to determine their detailed control algorithms. From the literature available [3, 4, 5, 6], a few algorithms use an approach similar to bangbang control. They usually have two or more threshold values for the wheel deceleration or the wheel slip. Once the calculated wheel deceleration or wheel slip is over one of the threshold values, the brake pressure is manded to increase, hold constant or decrease. This algorithm will result in a peakseeking strategy in the μ−slip curve or forcing the wheel deceleration/slip to be within a particular range. Finite state machine methods are also widely applied in the industry. Based upon the measured signals such s wheel velocity, vehicle deceleration and/or brake pressure, the operation of the vehicle is characterized by a set of different states, such as normal driving, lockup, free rolling ,etc. The rake pressure is then controlled to increase, hold constant or decrease based on the state the vehicle is in and other design logic. These two methods heavily rely on the experience of the designers and drivers. It is fairly difficult to analyze the controller’s performance during the design stage. The tuning of the controller is done purely on trial and error basis. The needs for a systematic design approach for the development are quite evident in this industry. Such needs motivated the research efforts that result in [9]. In particular, the truck ABS problems are reformulated as a closedloop control problem. A cascade loop structure, as shown in Figure 1, as well as various control algorithms are proposed. The outer loop, which includes the vehicle velocity estimation and desired slip calculation, provides the mand signal, Vwd , for the inner wheel velocity loop. The separation of the outer and inner loop designs, similar to the separation principle in linear system theory, are only made possible in the framework of Figure 1. Figure 1: A Cascade Structure for ABS The vehicle velocity estimation and the wheel velocity controller are the key design issues. A nonlinear filter approach, based on the work。