1、PDF外文：http:/ 南 交 通 大 学 本科毕业设计（外文翻译） Control of Tower Cranes With Double-Pendulum Payload Dynamics 运用双摆载荷动力学控制塔式起重机 年 级 : 2006 学 &nbs
2、p; 号 : 20061112 姓 名 : 陈东 专 业 : 机械设计制造及其自动化 指导老师 : 于兰峰
3、; 2010 年 6 月 西南交通大学本科毕业设计（外文翻译） 第 1 页 Control of Tower Cranes With Double-Pendulum Payload Dynamics Joshua Vaughan, Dooroo Kim, and
4、 William Singhose Abstract： The usefulness of cranes is limited because the payload is supported by an overhead suspension cable that allows oscilation to occur during crane motion. Under certain conditions, the payload dynamics may introduce an additional oscillatory mode that creates a
5、 double pendulum. This paper presents an analysis of this effect on tower cranes. This paper also reviews a command generation technique to suppress the oscillatory dynamics with robustness to frequency changes. Experimental results are presented to verify that the proposed method can improve the ab
6、ility of crane operators to drive a double-pendulum tower crane. The performance improvements occurred during both local and teleoperated control. Key words： Crane , input shaping , tower crane oscillation , vibration I. INTRODUCTION The study of crane dynamics and advanced control metho
7、ds has received significant attention. Cranes can roughly be divided into three categories based upon their primary dynamic properties and the coordinate system that most naturally describes the location of the suspe
8、nsion cable connection point. The first category, bridge cranes, operate in Cartesian space, as shown in Fig. 1(a). The trolley moves along a bridge, whose motion is perpendicular to that of &
9、nbsp;the trolley. Bridge cranes that can travel on a mobile base are often called gantry cranes. Bridge cranes are common in factories, warehouses, and shipyards. The second major category of cranes is boom cranes, such as the one sketched in Fig. 1(b). Boom cranes are best d
10、escribed in spherical coordinates, where a boom rotates about axes both perpendicular and parallel to the ground. In Fig. 1(b), is the rotation about the vertical, Z-axis, and is the rotation about the horizontal, Y -axis. The payload is supported from a suspension cable at the end of th
11、e boom. Boom cranes are often placed on a mobile base that allows them to change their workspace. The third major category of cranes is tower cranes, like the one sketched in Fig. 1(c). These are most naturally described by cylindrical coordinates. A horizontal jib arm rotates around a vertica
12、l tower. The payload is supported by a cable from the trolley, which moves 西南交通大学本科毕业设计（外文翻译） 第 2 页 radially along the jib arm. Tower cranes are commonly used in the construction of
13、multistory buildings and have the advantage of having a small footprint-to-workspace ratio. Primary disadvantages of tower and boom cranes, from a control design viewpoint, are the nonlinear dynamics due to the rotational nature of the cranes, in addition to
14、 the less intuitive natural coordinate systems. A common characteristic among all cranes is that the pay- load is supported via an overhead suspension cable. While this provides the hoisting functionality of the crane, it also presents several challenges, the primary of which is payload oscillation.
15、 Motion of the crane will often lead to large payload oscillations. These payload oscillations have many detrimental effects including degrading payload positioning accuracy, increasing task completion time, an
16、d decreasing safety. A large research effort has been directed at reducing oscillations. An overview of these efforts in crane control, concentrating mainly on feedback methods, is provided in 1. Some researchers have proposed smooth commands to reduce excitation of system flexible modes 25. Crane c
17、ontrol methods based on command shaping are reviewed in 6. Many researchers have focused on feedback methods, which necessitate the addition necessitate the addition of sensors to the crane and can prove difficult to use in conjunction with human operators. For example, some quayside cranes ha
18、ve been equipped with sophisticated feedback control systems to dampen payload sway. However, the motions induced by the computer control annoyed some of the human operators. As a result, the human operators disabled the feedback controllers. Given that the vast majority of cranes are driven by huma
19、n operators and will never be equipped with computer-based feedback, feedback methods are not considered in this paper. Input shaping 7, 8 is one control method that dramatically reduces payload oscillation by intelligently shaping the commands generated by human operators 9, 10. U
20、sing rough estimates of system natural frequencies and damping ratios, a series of impulses, called the input shaper, is designed. The convolution of the input shaper and the original command is then used to drive the system. This process is demonstrated with atwo-impulse input shaper and a step command in Fig. 2. Note that the rise time of the command is increased by the duration of the input shaper. This small increase in the rise time is normally on the order of 0.51 periods of the dominant vibration mode.
