Pneumatic cylinder actuators are significantly utilized for industry automatic systems in the fields of mechanical applications. We propose a novel control method for pneumatic cylinder actuator systems including stochastic friction dynamics. The proposed control mechanism is linearly composed of nominal control and auxiliary control variables. The former is designed from linear system model without friction terms by using a previous linear system theory and the latter is constructed as a function of friction estimation which is carried out by a well-known least square algorithm for reducing the control error due to random friction dynamics. We accomplish numerical simulation to demonstrate reliability of the proposed control method and conduct a comparative study to improve its superiority.

Recently, the automatic laser-piercing has become a subject of growing research area in the hydroforming of car body and robotic fields. Generally, the laser-cutting with 6-DOF robot system has 3D error due to a gear backlash and inaccurate calibration method between sensor and cutting-tool. The objective of this article is to study the automatic laser-cutting for the micro-hole piercing of engine cradles. The development of redundant micro-control module and laser vision sensor contributes to the implementation of precise laser cutting. To obtain higher a performance of control module, the calibration algorithm between cutting-tool and laser sensor is required. The implementation of this methodology will be describe. The optimal path generation for a good quality of cutting section is also explained in detail. The experimental results demonstrate the successful operation in the automatic micro-hole piercing. It shows a validity of the micro-motion mechanism and robot‘s calibration algorithm in laser sensor.