Time-Optimal Negative Input Shapers

Abstract

Input shaping reduces residual vibration in computer controlled machines by convolving a sequence of impulses with a desired system command. The resulting shaped input is then used to drive the system. The impulse sequence has traditionally contained only positively valued impulses. However, when the impulses are allowed to have negative amplitudes, the rise time can be improved. Unfortunately, excitation of unmodeled high modes and overcurrenting of the actuators may accompany the improved rise time. Solutions to the problem of high-mode excitation and overcurrenting are presented. Furthermore, a simple look-up method is presented that facilitates the design of negative input shapers. The performance of negative shapers is evaluated experimentally on two systems; one driven by a piezo actuator and the other equipped with DC motors.

The Residual Vibration Control of Robot Arm with Length-Changing Using Input Shaping Filter

“…By adding constraints, Singer and Seering developed input shaping to 3 impulses and obtained a good performance by applying to the robot system [2]. Singhose presented a multi-hump EI input shaper permitted residual vibration to some extent(for example 5%) and has broad frequency range for residual vibration reduction [3][4][5]. When the robot with a flexible beam picks up the things, both of the frequency and the damping are changed at the same time.…”

New aspects of input shaping control to damp oscillations of a compliant force sensor

“…However requiring positive amplitudes is a relatively restrictive constraint that lead in general to long sequences of impulses. If fast responses are needed then it's recommendable to set constraints to the actuators's limitations and then solve for positive and negative amplitudes that satisfy them (Singhose [11]). A general form of these constraints is:…”

Numerical Aspects and Performances of Trajectory Planning Methods of Flexible Axes

“…[5,6]. On another hand, the most popular damping scheme consists of a bang-bang profile in jerk (which is the derivative of acceleration), and has been proven to be related to input shapers with negative weights [7]. The goal of the paper is to compare different bang-bang laws (shapers, jerk.…”