An Adjustable Zero Vibration Input Shaping Control Scheme for Overhead Crane Systems

This article presents a modified zero vibration (ZV) input shaping technique to address the sensitivity and flexibility limitations of the classic ZV shapers commonly implemented in overhead crane applications. Starting with the classical ZV formulation, new parameters are introduced to optimize the control system performance according to a versatile objective function. The new shaper enhances the design flexibility and operational domain of the shaper, while it inherits the robustness properties and computational efficiency of the ZV scheme. Unlike the original ZV shaper, the proposed shaper allows for the point-to-point maneuver time to be fixed. The sensitivity analysis of the controller confirms that the new shaper effectively reduces the ZV sensitivity to the cable length variations.

An Input Shaping Control Scheme with Application on Overhead Cranes

A new optimization technique is developed to generate a step-input acceleration function for an input shaping harmonic system. This approach is integrated into an overhead crane model for a rest-to-rest maneuver with standard and nonstandard maneuver settings. The proposed method guarantees the satisfaction of the system constraints and desired final conditions, while it minimizes the system sensitivity to crane cable-length variations. The minimal system sensitivity is achieved through an optimization algorithm that provides zero vibration and a minimum integral of system sensitivity over a continuous range of crane cable length. Numerical simulations are conducted to demonstrate the feasibility of the proposed shaper in eliminating the residual vibration at the end of a programmed maneuver. Sensitivity analyses are also performed to verify the robustness of the new shaper. In comparison to the previous shapers, the new methodology is significantly less sensitive and can effectively handle different arbitrary maneuver times.

Quick Suppression of Vibration of Robot via Hybrid Input Shaping Control Strategy

When the vibration amplitude and resonant frequency bandwidth of each mode are different in the multiple-modal system, the response time of a system is increased but the residual vibration is effectively reduced by the positive impulses multiple-modal input shapers. However, a negative impulses hybrid multiple-modal input shaping method can solve those problems. The basic principle of this control strategy and a 3-DOF parallel robot were introduced. Six negative impulses hybrid input shapers to reduce vibration of the first two modes were constructed based on the robot. Using simulation methods, the response time and vibration suppression abilities of various negative impulses hybrid two-modal input shapers (NHTIS) were obtained by analyzing the vibration response curves of these input shapers, and comparing with positive and negative impulses two-modal input shapers, respectively. The results show that the NHTIS can improve the response speed of the system while significantly reducing the multiple-modal residual vibration.