Research of Motion Control for Vibratory Hammer
2015
Sandra Veinberga, Mārtiņš Greiškāns, Mārtiņš Irbe, Dmitrijs Ribaks

This article considers a vertical vibratory hammer with one degree of freedom . For variation of excitation force, the time or phase plane coordinate functions are used. The objective was to analyze variety of different motion conditions and to detect stable motion of the vibratory hammer. The main advantages of adaptive control (phase plane coordinate functions) are determined. Recommendations for motion control in a real system with two sensors (i.e., coordinate and speed) are presented. Key features in an efficient and optimal vibratory hammer operation are its working speed and beat vibration intensity. Minimizing operational time for planned assignments is crucial in manufacturing industry today. In this article, three different types of excitation control functions for vibratory hammers are presented. At first, the control function with harmonic force excitation was considered. It was established that finding an optimal vibration frequency is rather time-consuming and inaccurate. If the frequency is set too low, the hammer has the tendency to stick to the surface. As a result, the time, necessary for operations, increases. On the other hand, if the frequency is set too high, there is a possibility of an inefficient impact speed or amplitude. The main reason is the lack of feedback between the applied force and the impact. As more efficient, the models with adaptive control of excitation function were found. Adaptive excitation with a single sensor (speed function) and with two sensors (speed and coordinate functions) was considered. It was established that this kind of the control model is much more efficient and easier to control. In this case, a steady state occurs in a few cycles and oscillations are uniform and efficient. When the control with two sensors is used, it is possible to control the constant k. The value for k can be adjusted from zero to infinity. If the value is set to zero, the vibratory hammer works at a full impact value; if the value is set to infinity, a zero-impact state is acquired.


Keywords
adaptive excitation force, harmonic excitation, motion in phase plane, vibratory hammer

Veinberga, S., Greiškāns, M., Irbe, M., Ribaks, D. Research of Motion Control for Vibratory Hammer. Mechanics. Vol.36, 2015, pp.82-86. ISSN 1407-8015. e-ISSN 2255-8721.

Publication language
Latvian (lv)
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