Dynamometer Performance Modeling and Experimental Assessment

Abstract

Piezoelectric dynamometers are generally used for force measuring. During transient period, their performance is limited because the signals they delivered are distorted by their dynamic behavior and then are different from applied force. This paper proposes a method to identify the dynamic characteristics of the dynamometer so that the distortion of the signal can be compensated leading to the actual force. This method is based on the interrupted cutting of a specially designed workpiece that provides a strong broadband excitation. The three components of the exciting force and the acceleration of the gravity center of the dynamometer cover plate are measured simultaneously. Although the input acceleration components are correlated in the frequency bandwidth of interest, the nine terms of the dynamometer transfer matrix are determined from only one cutting experiment. To assess the developed method, series of different pulse excitations are carried out. Then, the determined transfer matrix is used for dynamic cutting force compensation under some milling operations. [S0022-0434(00)01003-0]

Advanced monitoring of machining operations

“…Methods for online compensation of force measurement errors can be broadly arranged into two classes. In the first class, there are the systems that attenuate the impact of forces caused by vibration of the dynamometer and mass; this is accomplished by the estimation of the errors caused by inertia and the subtraction of these errors from the recorded signal [36]. In the second class of online methods, the compensation is accomplished by means of adaptive filtering [27,[37][38][39].…”

Suppressing vibrations of machining processes in both feed and radial directions using an optimal control strategy: The case of interrupted cutting

“…Cutting force characteristics in both the feed and the radial directions are shown in Fig. 4 and accordance with the force profile as given in [7,8]. The forces have three components namely, an impulse and a saw tooth components resulting form vibration of the tool after being subject to the impact (both at the spindle rotational frequency), in addition to a random part resulting form the stochastic nature of the cutting process.…”

“…The characteristics of the cutting forces resulting from interrupted cutting are obtained form references [7,8]. The values are modified to represent worst-case scenario where parts with higher hardness are to be machined.…”

“…Theoretical and experimental data on the stability of the interrupted cutting process was presented by Mann et al [5,6] for the purpose of improving surface quality and prevent chatter or instability in machining processes. Tounsi and Otho [7,8] have explored the effect of machine tool vibration on the surface quality and the interaction of the machine tool-workpiece in a Greek letters ς damping ratio of filter ω f natural frequency of filter (rad/s) Subscripts f feed direction fF feed direction-transmitted force fS feed direction-structure r radial direction rF radial direction-transmitted force rS radial direction-structure milling process. They have presented valuable information on the nature of cutting process and shown that the process is random in nature.…”

Investigation of thermal behavior on cylinder liner during its boring process

“…Thus, in this paper, the magnitude of the cutting force and temperature distribution in cylinder liner under various cutting conditions will be investigated. The cutting force may be easily measured using a dynamometer or predicted by applying some widely models [3,4]. In this paper, the cutting forces directly are measured from experiment.…”