Vibration control of linear robots using a piezoelectric actuator

Abstract

This paper presents the results of vibration control strategy for high-speed linear robots using an auxiliary piezoelectric actuator. With acceleration reaching 3 g, rapid horizontal slewing motion inevitably excites the structural resonances of the robot and generates vertical vibration forces exceeding the tolerance of the end-effector. Instead of controlling the robot vibration from the main actuators (ac servomotors with limited bandwidth), a piezoelectric actuator is deployed to provide vibration suppression at the load in the direction. This way the robot is treated as a disturbance generator while the piezoactuator is considered as the plant. A digital servocompensator is then designed and implemented to suppress these vibration modes. Typically, attenuation is achieved for the dominant mode with 30 dB and other modes with 15 dB. Suppression of vibration up to seven modes has been implemented satisfactorily.

Adaptive vibration control of piezoelectric cantilever beams with uncertainties

“…Consider the symmetrical piezoelectric laminated beams with sensors/actuators, if the first-order transverse shear deformation theory of the laminated beam is used, the displacement of any point outside the middle plane of beam can be obtained as [4] ( 1 )…”

“…C. Qu . W. Liu 1 College of Mechanical and Electronical Engineering, Nanyang Normal University, Nanyang 473061, China E-mail: cuiminyue@sina.com material or embedding piezoelectric material is usually ignored, and a distributed moment is used to express the control effect of piezoelectric layer on the structure [4][5][6][7], which can not accurately reflect the intrinsic mechanical characteristics of the piezoelectric smart structure. The finite element model of piezoelectric structure usually has a high order, which can not be directly used in the design of controller.…”

Development of the end-effector measurement system for a 6-axis welding robot

“…Also, many methods have been used to tune controller gains in a joint space. [15][16][17] However, the gains have to be re-tuned for operating multi-axis simultaneously because tuned gains in a joint space are difficult to be adopted in a Cartesian space. 12 Moreover in the case of MIMO, since there are many number of gains, the overall tuning of gains can be more complex.…”

An Analytical Approach to Integral Resonant Control of Second-Order Systems

“…Active vibration control is commonly used to damp systems where bandwidth, precision, or life time are key performance requirements, for example, robotic manipulators [3]- [5], diskdrives [6], aircraft wings [7], nanopositioning stages [8], [9], scanning probe microscopes [10], and high-density memory storage devices [11].…”