William E. Singhose

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We investigate the constant amplitude nature of several time-optimal input shaping designs for controlling exible structures. We rst discuss the equivalence of the time-optimal zero-vibration shaper with the traditional time-optimal control problem. Then we show that several robust time-optimal shaper designs for exible systems are equivalent to the(More)
The effects of input shaping on trajectory following were investigated by simulating the response of a fourth-order system with orthogonal modes and conducting experiments on an XY positioning stage. For nearly all values of damping and frequency ratio, the shaped inputs result in significantly better trajectory following than unshaped inputs. When the(More)
Precise manipulation of payloads is difficult with cranes. Oscillation can be induced into the lightly damped system by motion of the bridge or trolley, or from environmental disturbances. To address both sources of oscillation, a combined feedback and input shaping controller is developed. The controller is comprised of three distinct modules. A feedback(More)
Input shaping reduces residual vibrations by convolving a sequence of impulses, an input shaper, with the desired system command. Using negative impulses in the shaper leads to faster maneuvers. Unfortunately, when negative input shapers are used, there is no guarantee that the shaped command will satisfy actuator limitations. A new type of negative input(More)
We investigate the characteristics of constant-amplitude input shapers for robust time-optimal maneuvers of exi-ble structures. Trends in the timing of the shaper impulses are shown as a function of the system damping constant and move distance. The insensitivity to modeling errors, time-optimality, amount of vibration caused during maneuvers, and high(More)
Precise position control and rapid rest-to-rest motion is the desired objective in a variety of applications. The desire for reducing the maneuver time requires reducing the inertia of the structure which subsequently results in low frequency dynamics. The requirement of precise position control implies that the residual vibration of the structure should be(More)
Input shaping is a method for reducing residual vibrations in computer controlled machines. Vibration is eliminated by convolving a sequence of impulses, an input shaper, with a desired system command to produce a shaped input. The shaped input is then used to drive the system. The input shaper has traditionally contained only positively valued impulses.(More)