外文翻译---振动抑制的固定式悬臂起重机演示(编辑修改稿)

外文翻译---振动抑制的固定式悬臂起重机演示(编辑修改稿)内容摘要：

s will from now on be referred to as the radial (0,) and the tangential (e1 ). The input to this system is the hub rotation trajectory y ( t ) and the outputs are the rotation angles of the loadline, 0, ( t ),e, ( t ) . The experimental system uses a constant velocity, puter controlled, directdrive, motor. Physical values for x, m, L are given in Table 1. . 山东建筑大学毕业设计（或毕业论文，二选一）外文文献及译文 4 As mentioned in the introduction, several maneuvers are examined all of which consist of a 90 jib rotation. The first is designed such that the payload is residual oscillation free .The second allows only tangential oscillation at the end of maneuver, while the third allows only radial oscillation of the payload. 3. RESULTS Table 2 shows the parameters obtained via the optimization process which result in the three maneuvers of interest. Plots of jib rotation are shown in Fig. 3 through Fig. 5. The angular accelerationprofiles implemented on the hardware, described in Section2, produce the desired maneuvers with no modification of the inputs. This implies an excellent ability to model and simulate this system. The absence of residual oscillation was determined by observation during testing. Due to the agreement between simulation and experiment, simulation plots are presented. The residual oscillation free maneuver of Fig. 3 uses an acceleration profile symmetric in time about the half period of the maneuver. This is consistent with the results obtained by Petterson and Robit lo. Allowing pendulum sway in either the radial or tangential directions only, requires nonsymmetric acceleration histories as in Fig. 4 and Fig. 5. Plots of the pendulum sway are shown in Fig. 6 through Fig. 8. Centrifugal effects during the maneuver are illustrated by Fig. 9 through Fig. 11which show the projection of the payload and the jib end onto the horizontal surface. In all cases the load is observed moving initially outward from the tip path. The acceleration profiles developed here purposely excite the oscillatory motion of the load. This is illustrated by investigating the Fourier series of the acceleration history. Examination of the quasistatic stiffness matrix of Eq. 6 throughout the residual oscillationfree maneuver indicates only slight changes in the quasistatic natural frequencies of the load. Specifically, the 山东建筑大学毕业设计（或毕业论文，二选一）外文文献及译文 5 nominal (nonrotating)natural frequency in both radial and tangential directions is Hz .The initial acceleration pulse, with zero velocity, results in a slight increase of this frequency. However, the softening effect of the angular velocity during the maneuver causes the quasistatic natural frequency to decrease to Hz at the halfperiod of the maneuver. This change in quasistatic natural frequency is symmetric in time about the halfperiod. Fig. 12 shows a 20term Fourier sine series expansion of the input acceleration history. The first 5 coefficients of the jib angle history, obtained from integrating the acceleration history, are given in Table 3. Finally, some mention of the robustness of this technique is in order. It is expected。