This paper presents a non-model based control approach to reduce payload oscillations in hydraulic load handling machines. Hydraulic mobile machinery are subjected to different kinds of vibrations related to their actuation, which hamper productivity and safety. In particular, these oscillations can occur at the machine structure, at the operator cabin or at the payload. While several techniques have been proposed to specifically address the first two forms of vibrations, the problem of limiting payload oscillations has encountered less attention by researchers in the fluid power field. The particular control technique proposed in this work is pressure feedback, and utilizes pressure sensor which can be located in well protected areas of the hydraulic system of the machine. The control method is based on an online identification of the frequency of load oscillations and selectively reduces these oscillations by acting on the hydraulic actuators of the machine. With reference to a hydraulic crane installed at the authors’ research center, this paper details the methodology, particularly focusing on the technique utilized for the online identification of the nature of load oscillations. Experimental results are presented to show the effectiveness of the proposed method to reduce payload oscillations, and demonstrate its applicability for hydraulic load handling machines.
This paper presents an innovative approach towards the active vibration damping of mobile hydraulic machines. The authors’ research group recently introduced a novel control strategy based on pressure feedback and on an optimization procedure. The success of the optimization lies on the efficient quantification of the vibration extend which is the objective to be minimized. This paper addresses the definition of the objective function introducing a new method which does not require a priori knowledge of the working cycle. This approach enables the control strategy to be potentially applied to any kind of working scenario and does not require the intervention of a control designer.
The results presented in this paper show that the novel method is able to effectively attenuate the undesired oscillations while not affecting the actuator velocity.
This article presents an innovative pressure feedback method to address undesired payload oscillations in hydraulic load-handling machines, which have a negative impact on both machine productivity and safety. Tracking control techniques in these machines are often not applicable due to the difficulty or the cost associated with the installation of the feedback sensors on the payload. In this work, by means of pressure sensors installed on the hydraulic system, the payload oscillation frequency is first detected by analyzing the frequency content of the measured pressure and then counteracted through a sinusoidal-based excitation command on the machine actuator. The work particularly addresses the challenges related to the use of the same actuator for detecting and quantifying the oscillation (in both frequency and amplitude) and for reducing the payload oscillations. In fact, interference on the feedback pressure signal due to the control action is present. Experimental results on a truck-mounted hydraulic crane show how the proposed technique permits to reduce payload oscillation in order of 50%, which is comparable to other less-practical tracking control techniques.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.