Hybrid Position/Force Control of the Macro/Micro Manipulator for Assembly of PCB Utilizing Fuzzy Control

Currently, electronic components are very thin as well as fragile and their assembly on PCB boards is highly sensitive. The components may be damaged and broken in response to an excessive force. Therefore, it is necessary to use a mechanism with force control ability. A mechanism with a large member (macro) for long movements and a small member (micro) for short and delicate movements, is selected to provide accurate force control as well as high speed in installation. The macro member is rapidly approaches the surface of the PCB with the position control and then the micro member initiate its movement. As the micro member contacts the surface of the PCB, the position control is switched to force control and enables the installation of the device with controlled force. At the first attempt, PID controller is used. Thereafter, the fuzzy controller is selected to control the system. The fuzzy controller has a better performance and reduces the disturbances during installation. The relation between maximum contact force and contact time with velocity is also investigated and optimal velocity is determined.