About Robotics Laboratory

The "Robotics Laboratory" has been established almost at the same time of the opening of POSTECH with the immediate mission to the automation of "Pohang Steel Company(POSCO)" in addition to the basic research aiming world leading robot technology.

Most of the people have a memory of the robot “ATOM” in the cartoon movie. Although the realization of the flying insect robot into the real world is coming, we still have a dream to make it come true.

From the beginning of POSTECH, the robotics area has been one of the major research areas. During the last 21 years, we tried to develop robots by ourselves. The “7-DOF Direct Drive Arm” was the first robot that we developed. After that, we developed various robots - ROBOT HANDS, DD-ARMS, MOBILE ROBOT, TELE-OPERATION SYSTEM and so on. Especially, we are specialized in the area of redundant manipulator in both theory and experiments.

The robotics lab focuses on 3 topics nowadays: Control, underwater robotics, medical robot applications (such as micro robotics, surgical robot applications, and understanding human behavior using sEMG)

The development of robot and sensor to replace human in a dangerous underwater environment is the final target of the underwater group. We developed the PETASUS which is a 6 DOF AUV (Autonomous Underwater Vehicle) with a robot arm, and we solved the complex dynamics equations of the AUV with efficient control schemes. Recently, this group has focused on the development of underwater sensors and localization system which is the basic problem of underwater perception. We proposed a novel range sensor using the signal strength of an electromagnetic wave, and we verified the performance of proposed sensor in several conditions. This sensor can be applied in academic and military fields such as navigation system of underwater vehicle, composition of sensor networks and so on.

Control group have focused on the development of robust control algorithms based on nonlinear H_inf control theory. We showed that why conventional PID controller is robust and optimal and analyzed the performance limitation of PID controller. We proposed a composite tuning law to tune easily 3 parameters of PID gains. The applications of the controllers includes hard disk control, precison XY table, DVD, robots, and so on. Recently, this group is doing research on the development of hydraulic actuators that have high torque control capabilities. Recently, this group is developing hydraulic actuators that have high torque control capabilities using two different approaches: Hydro-Elastic Actuation(HEA) and Electro-Hydrostatic Actuation(EHA). HEA system is a hydraulic system with a mechanical spring, which converts high position control capability of hydraulic system to fast & accurate torque generation. EHA system is a hydraulic system with electric motor, which transmits motor power and amplifies motor torque. We proposed a robust control strategy including disturbance observer (DOB) and model based controller for both approaches.

Medical robot applications consist of three parts: micro robotics, surgical robotics, and sEMG applications First, the micro robotics group has been focusing on robotics-based approaches to micro/nano technologies, such as microfluidics for lab-on-a-chip devices. The research focuses on developing three major components to be applied in micro systems: actuator, sensing method and controller. The actuator is to achieve higher degree of precision in driving fluids into a micro-chip and the sensing method is to acquire feedback information from microsystem, to achieve a feedback control scheme. Lastly, a robust controller is being designed to precisely manipulate fluid flow and micro-particles in a microfluidic chip. Using the developed actuators and control methods, various lab-on-a-chip applications can be realized such as valve-less flow switching, single-cell manipulation, particle focusing and so on.

Second, surgical robotics group is focusing on two research topics. One is medical palpation training system and the other one is microsurgical robot for Keratoplasty. Research on palpation training system aims realistic tumor rendering in order to improve a trainee's performance. augmented reality (AR) framework is used to guarantee the realism in real-time. Research on microsurgical robot for Keratoplasty aims at designing miniature mechanisms, to analyze the complex behavior of needle-tissue interaction and to make use of medical images to give visual feedback to the microsurgical robot system.

Third, surface electromyogram (sEMG) group is trying to study the human behavior using sEMG information. sEMG is a non-invasive bioelectric signal that comes from the functional units of skeletal muscles underneath our skin. Since it delivers muscle activities with highly nonlinear relationship, this group is developing algorithms based on the probabilistic models of machine learning and pattern recognition to extract the physiological aspects of human dynamic motion. Also, this group is developing a MEMS sensor that painlessly penetrates the outmost layer of the skin to reduce the electrical impedance and improve the quality of this bioelectric signal. The ultimate objective of this research is to measure and interpret the muscular activity better for further applications such as robot control by understanding the origin of the signal and human behavior.

2020 lab members