Modelling and simulation of an automatic grinding system using a hand grinder

Abstract

A grinding process model for an automatic grinding system with grinding force control is developed in this paper. This grinding system utilises an electric hand grinder, driven by a CNC machine centre and a force sensor for force measurement. This model includes compliance of the grinding system and is initially represented by a series of springs. The stiffness of each component is estimated in this study and it is found that the model may be simplified into a single spring-mass system. A corresponding PID controller is designed for the purpose of grinding force control, which calculates the appropriate CNC spindle displacement according to the force measured by the force sensor. Computer simulation results show that the system settling time is less than 0.25 s.

Grinding force control in an automatic surface finishing system

“…The following gain values were found: K d = 0.0443, K p = 0.0891, and K i = 11.762. The numerical simulation results show that an overshoot of less than 3% was obtained using these gains [13]. These values will be used in the following grinding experiments.…”

“…The spring constant is roughly the ratio of normal grinding force to grinding depth, and the mass includes the electric hand grinder and the holder. A corresponding PID controller to maintain a constant grinding force was also designed [13]. The following gain values were found: K d = 0.0443, K p = 0.0891, and K i = 11.762.…”

“…A grinding process model for this grinding system was developed [13]. The model originally contained two masses and four springs.…”

Closed-loop force control for a semi-automatic grinding system

“…Equation (3-2) suggests a none-linear relationship between normal grinding force and depth of cut. To simplify the model to a linear relationship, the ratio of the normal grinding force to depth of cut is assumed to be a constant value [1].…”