Abstract. This paper designs the closed-loop feedback control system of MEDM, which is based on the motion control card and data acquisition card. To ensure the accuracy of the process, the gap can be regulated through the analysis of discharge condition and the analysis and treatment of the gap voltage, and then a servo control scheme on small holes machining is presented. Through this way, the electrode loss compensation scheme can be solved, which can improve the efficiency and practicality of MEDM.

Purpose – The purpose of this paper is to discuss an example of modelling with experiments of robot prototype with dependent joint concept, including a full description of related functionalities. Reduction in active degrees of freedom in a machine can lead to improved accuracy, improved reliability and lower cost. The reconfiguration of machines and systems is a key technology for future responsive manufacturing systems. The concept of dependent joints helps to implement much specified sub-workspaces depending on functional needs in the machine. Design/methodology/approach – This is inherently made possible using smart mechanical concepts having embedded sensors and reconfigurable control systems. This paper introduces structural reconfiguration systems and discusses a sample approach to functional reconfiguration. Findings – A successful manipulator design with extended features when considering reduction in active degrees of freedom in a machine would lead to specific sub-workspace with improved accuracy, improved reliability and lower cost. Research limitations/implications – Reduction in active degrees of freedom in a machine can lead not only towards a dedicated functional workspace but also towards improved accuracy, improved reliability and lower cost. Originality/value – This paper is of value to engineers and researchers developing robotic manipulators for use in various aspects of industry.