Electronic control hydraulic impactor based on pressure feedback
The impact energy of the traditional hydraulic impactor can be regulated manually between the second and the third grade, and its impact frequency can not be adjusted independently. Also, they have to stop working for adjustment. In order to alter this situation, a new hydraulic impactor DBS500, which controlled by micro-electronic system, has been designed and its functions are showed as following: The impact energy can reach 500 joules and its impact frequency also realizes regulation from 0 to 8Hz steplessly. It can estimate the work object's nature by piston's rebound behavior. It can self-regulate the impact energy and frequency according to the object's nature, so that can improve the working efficiency and adapt the power of the loader.
Hydraulic Impactor Control Methods and Charts
Abstract The authors discuss the approved advanced control charts for operational cycles of hydraulic impacting machines. These control charts allow adjusting operational characteristics of the machines either using only pressure back-coupling between the fluid power system and distributor, or in combination with introduced additional pressure control. The article describes adaptive impacting machines equipped with the control charts which allow adjustment of blow energy and frequency subject to properties of a medium being fractured. It is emphasized that to expand the application range of hydraulic impactors, it is required to design high-frequency percussion machines with high impact capacity owing to improvement of distributors and due to transition to the increased power fluid pressure.
Automatic Smith-predictor tuning using optimal parameter mismatch
The Smith-predictor is famous for its delay-free characteristic and suitable for regulating systems with an excessively long time delay. However, it is sensitive to plant parameter variations based on some frequency domain studies. In this paper, detailed analyzes of the system performance through parametric and temporal mismatch are investigated and accompanied with closed form solutions. Based on the derived solutions, the optimal performance and stability characteristic of a Smith-predictor compensated control system is examined. It is found that the system performance can be improved by introducing an intentional parametric or temporal mismatch and the corresponding optimal tunings are determined based on the value of a normalized plant parameter. The theoretical results are also summarized to form an automatic Smith-predictor tuning procedure and verified experimentally on a fluid temperature control system for a quiet hydraulic precision lathe.