Implementation of bi-directional searching Chemical Reaction Optimization (CRO) algorithm towards achieving cutting tool indexing time minimization in Automatic Tool Changer(ATC)

Determining the optimum cutting tool positions in a tool magazine is a challenging task which involves a huge searching space. Reduction of manufacturing time even by nanoseconds will highly be beneficial for all process industries. The prime focus of this research work is to reduce the total turret or tool indexing time in Automatic Tool Changer (ATC) which in turn curtails the idle non-cutting time of the bi-directional turret or tool magazine in a CNC machine. This variant of optimization problem falls under the category of non-deterministic hard polynomial (NP-hard) problem. Chemical Reaction Optimization (CRO) algorithm is proposed to determine the near optimal/global optimal solution with lesser computational cost. Five benchmark case studies are considered in this work to assess the robustness of the proposed algorithm. From the results, it is evident that the proposed algorithm yields solutions which matches or exceeds with the solution quality.

Development and Implementation of a Dynamic Force Measurement System for Automatic Tool Changer System and Drawbar Mechanism in Machining Center

Automatic tool changer system (ATCS) and drawbar mechanism (DM) are two of key basic parts in machining centers for realizing automatic tool-changing cycle. In the condition monitoring, fault diagnosis and failure warning of the ATCS and DM, the dynamic force is an important characteristic signal. However, there is little research about the specific dynamic force measurement system in this regard. Thus, a novel dynamic force measurement system (DFMS) is developed and implemented. Based on the BT40 toolholder, a resistance strain gauge-based force senor is used to convert the dynamic force signal into electrical signal. The real-time dynamic force acquiring system is controlled via an 8-bit RISC microcontroller. Digital measurements are obtained from the 24-bit sigma-delta analog-to-digital converter with a programmable gain array, which then are transmitted to the upper computer software via a wireless transceiver for display and storage. Finally, a Teager energy operator based dual-threshold two sentences endpoint detection method is proposed to extract the maximum dynamic force and the duration time. Experimental results show that the DFMS is reliable and can be easily used to detect the dynamic force for the ATCS and DM.

Influence of relative humidity and air temperature on the stopping position of the automatic tool changer in a CNC machine when using a pneumatic cylinder

The automatic tool changer (ATC) in computerized numerical control (CNC) milling machine often uses pneumatic dynamic sources. Friction in the pneumatic cylinder affects the ATC’s stopping position; this friction depends on many factors, including the air environment’s relative humidity and temperature. This paper presents the results of research on the effects of relative humidity (RH) and air temperature (T) on the stopping position of an ATC using a pneumatic cylinder. Studies were conducted at temperatures of [Formula: see text]C, [Formula: see text]C and [Formula: see text]C and relative humidity values of 51%, 75% and 99% for different speeds of the pneumatic cylinder (30, 50 and 100 mm/s). The results show that when the humidity increases from 51% to 99% and the temperature increases from [Formula: see text]C to [Formula: see text]C, the friction force decreases. The friction force is related to the relative humidity and temperature of the air. Thus, the deviation of the ATC’s stopping position depends on the relative humidity and temperature of the area under investigation.

Design and Research of Automatic Tool Changer System for Multistation Spring Forming Machine

Currently, the spring machine tool is fixed by means of manual clamping and positioning by bolts. The automation of the tool change is low, and the accurate value of the tool position cannot be determined. The automatic tool change system for spring machine was designed by using the standard functional parts of the automatic tool change system of the machining center. It mainly includes the design of the automatic loose clamp device and that of the multispindle automatic tool change arm. After static analysis, the deformation of the automatic tool change arm is 0.153 mm, which satisfies the requirements for usage. Kinematic analysis of the designed automatic tool change arm was carried out. After actual verification, the designed automatic tool change system of spring machine realizes the functions of the tools automatic replacement and positioning of the spring machine, which improves the automation of the spring forming equipment.