tailieunhanh - Clutches and Brakes Design and Selection P012

Công nghệ cơ khí thường tạo ra các giả lập mô phỏng hoạt động của các đối tượng, như quy trình chế tạo thực tế theo trình tự tối ưu hóa sự thực hiện, hiệu quả kinh tế và chi phí năng lượng trước khi quyết định lựa chọn một thiết kế cụ thể. Các bản vẽ kỹ thuật để chế tạo là sản phẩm cuối cùng của khâu thiết kế. Chúng phải thỏa mãn hai mục đích: bao gồm đầy đủ tất cả các thông tin cần thiết để chế tạo và cũng còn là một tiêu chí kiểm soát. | 12 Antilock Braking Systems Antilock braking systems also known as antiskid braking systems for vehicles are discussed here because they represent perhaps the most involved commonly used systems for automatic brake control. The data collection analysis and system design involved may suggest initial procedures to be followed for clutch and brake automation in other applications. Design of an antilock system ABS for highway vehicles requires decisions to what is to be measured how it is to be measured and how to use the data to prevent skidding. These systems are different from the early antilock systems in that they are computer based so they collect and process more data. The first patent for antilock brakes was granted in Germany in 1905 1 and the first antilock brakes for railroad cars were available in 1943 2 . Electronic control of antilock brakes was widely incorporated into aircraft by 1960 3 in order both to control aircraft skidding and to prevent excessive wear to the tires on the landing gear of large aircraft. Although it may be difficult to specify when the first extension to highway vehicles began Ford and Kelsey Hayes produced an ABS system for the rear wheels only of the 1969 Thunderbird 4 . Introduction of what was said to be modern electronically controlled ABS for passenger cars was by Daimler-Benz 5 and BOSCH 6 in 1978. Because of the proprietary nature of the available antiskid and traction control systems the latter portion of this chapter dealing with antiskid braking and traction control systems will be a combination of information from the literature and of conjecture regarding the possible techniques available for achieving brake control. Copyright 2004 Marcel Dekker Inc. I. TIRE ROAD FRICTION COEFFICIENT Antilock brake control for stopping a vehicle in what is intended to be a straight-line path clearly requires some method for detecting the skid or slip of each wheel for assimilating the data from all wheels for analyzing this data to .