Implementing Modified Command Filtering to Eliminate Multiple Modes of Vibration

Abstract

The requirements for large robots in waste mancgement ctd space mplications necessitate active vibrtion control lgorithms. The use of long, flexible links provides the needed range of motion but their inherent flexibility can generate undesirable vibrations making both control and endpoint positioning difficult. This pcper presents two shaing aigorithms, the impulse shaping method and the modified command filtering technique, to eliminae thefirst two modes ofvibrtiqn in a flexible maupulator. The vibration suppression cpabilities ae demonstraWed uing a large elliptic

Command shaping for flexible systems: A review of the first 50 years

“…Given the importance of the adaptation algorithm to the overall success of this approach to command shaping, it is important to compare the various methods and match their capabilities and properties with the application at hand. 48,[52][53][54][55] In addition to the real-time computational burden, another significant challenge for some applications is the effect of noise in the system. Noise can erroneously indicate that the dynamic properties are changing.…”

Time-varying input shaping technique applied to vibration reduction of an industrial robot

“…The scheduling methods may be classified into two groups: * A look-up table is used to provide the values of the time-varying parameters for each joint configuration of a robot (Rappole, 1992). * A robot dynamics model is computed on-line to obtain the values of the time-varying parameters (Magee & Book, 1993;Cho & Park, 1995;Tzes & Yurkovich, 1993).…”

“…However, the closedloop approach makes overall systems complex and expensive because the increased number of states due to vibration modes increases the order of the control law, thereby requiring more computation power and more sensors. As a remedy, many researchers have considered feedforward controllers (Singer & Seering, 1990;Magee & Book, 1993). The feedforward controller requires no additional cost because it does not need any sensors.…”

“…Rappole (1992) applied time-varying input shaping technique (TVIST) to a twolink flexible manipulator using look-up table that contains the information of configuration-dependent frequency. Magee and Book (1993) modified the IST to eliminate the first two modes of vibration in a large and flexible manipulator having configuration-dependent inertia. Cho and Park (1995) proposed a method for determining the exact time-varying impulse sequence for linear time-variant systems, and applied it to a two-link flexible robot.…”

Intelligent Backstepping System to Increase Input Shaping Performance in Suppressing Residual Vibration of a Flexible-Joint Robot Manipulator

“…The approximate of the stochastic system state by using finite-dimensional series expansion in the stochastic space was applied. Magee and Book in [44] presented a modified command filtering technique in discrete time. This modified filter ensures a more uniform output for each discrete-time sample as the system parameters vary with time.…”