• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.10
• /
• pp.25-31
• /
• 1995

In this paper, a direct drive scalar robot manipulator is constructed and its mechanical machanism for operation is explained. Also, a motion controller board for the direct drive robot manipulator was developed where the IBM 486 computer is the main controller. For the developed direct drive robot, a force/motion control algorithm based on an active compliance scheme is developed. A preliminary experiment using the developed direct drive for a peg-in-hole job was done by implementing the control algorithm.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.1052-1057
• /
• 1993

A scara type Direct Drive Arm(DDA) with two degrees-of-freedom is designed and implemented. The direct drive motor is used to furnish large torque to reduce the modeling error by the gear and chains. To control the DDA, a multiprocessor control structure with multirate dynamic control algorithm is designed. In the control algorithm, the dynamics of system is used to calculate the nominal control torque and the feedback controls are calculated with a parallel processing algorithm for each joint. The laboratory experiments on Hong-Ik DDA by dynamic control algorithm are presented and compared to that of PID control algorithm. This result shows that the proposed controller guarantees small trajectory error and stability. With this research, Hong-Ik DDA is expected to be utilized as A basic tool for robotics and control engineering.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.520-522
• /
• 1996

The Direct Drive Arm(DDA) is a SCARA typed direct drive manipulator with two degrees-of-freedom(DOF) using the direct drive motor of the NSK company. A controller system for the SCARA robot of DDA is designed using a DSP (TMS32Oc3O), which has the highest performance among the third DSP chips in the TI company. The design objective of the system is to implement dynamic control algorithms and neural control algorithms for real time learning which require a lot of calculations and large memory and have been tested only by simulations so far. The controller uses a DSP, a high speed D/A, 32-bit Counter and a large DRAM to implement advanced robot control algorithms.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.3 s.174
• /
• pp.653-660
• /
• 2000

The automatization by industrial robot of today is merely rely on to the simple position repeating works, but requirements of research and development to the force control which would adapt positively to various restriction or contacting works to environment. In this paper, a learning control algorithm using, neural networks is proposed for the position and force control by a direct-drive robot. The proposed controller is the feedback controller to which the learning function of neural network is added on to and has a character of improving controller's efficiency by learning. The effectiveness of the proposed algorithm is demonstrated by the experiment on the hybrid position and force control of a parallelogram link robot with a force sensor.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.12
• /
• pp.165-172
• /
• 1995

Many algorithms to enhance a speed performance of a robot have been studied, but it's rare to consider disign aspect of a robot arm for time optimal problem. In this paper, section demensions of a robot arm and a velocity profile of an end-effector were optimally designed to minimize the cycle time. Capacity of actuators, deflections of end-effector, and a fundamental natural frequency of the robot arm were constrained in optimal design. For a given path with a trapezoidal velocity profile, torques of each joint were calculated using the inverse kinematics and dynamics. For the SCARA type robot which is mainly used for assembly tasks, the time optimal design of each robot arm id presented with the above constraints.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.234-234
• /
• 2000

A direct torque control(DTC) based sensorless speed control system which employs a new closed loop flux observer is proposed. The flux observer takes an adaptive scheduling gains where motet speed is used as the scheduling variable. Adaptive nature comes from the fact that the estimated values of stator resistance and speed are included as observer parameters. The parameters of the PI controllers adopted in the adaptive law for the estimation of stator resistance and motor speed are determined by simple genetic algorithm. Simulation results in low speed region are given for comparison between proposed and conventional flux estimate scheme.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.136-136
• /
• 2000

The direct drive servo valve(DDV) is composed of a DC rotor, link, valve spool and displacement sensor(LVDT) where the spool is directly coupled to the DC motor through the link. Since the DDV is a kind of one-stage valve, the robust controller is required to overcome the flow force effect on the spool motion. The mathematical equations are derived and the stability, accuracy and response speed of a DDV are investigated analytically using a linearized system block diagram. Proportional control, PID control. Time-Delay control, Sliding Mode control, and Proportional control using the load pressure are applied to DDV to find which one shows the best control performance. The digital computer simulation results show that the proportional control using the load pressure satisfies the design requirement of response speed and steady state error regardless of the variation of load pressure,

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.11
• /
• pp.919-924
• /
• 2016

This paper proposes a robust control design method for improving the cornering stability of a personal electric vehicle equipped with in-wheel motors. In general, vehicles undergo severe parameter variations and unpredictable disturbances with respect to a wide range of driving conditions (e.g., road surface conditions and vehicle velocity conditions). For this reason, robust control design techniques are required to guarantee consistent driving performances and robustness against various driving conditions. In this paper, an adaptive sliding mode control method is employed to enhance cornering stability by controlling the direct-drive in-wheel motors independently. Additionally, in order to confirm the effectiveness of a proposed control method, real driving tests with an experimental personal electric vehicle are performed.

• The Journal of Korea Robotics Society
• /
• v.14 no.4
• /
• pp.348-356
• /
• 2019

The backdrivable servovalve is a desirable component for force and interaction control of hydraulic actuation systems because it provides direct force generation mechanical impedance reduction by its own inherent backdrivability. However, high parametric uncertainty and friction effects inside the hydraulic actuation system significantly degrade its advantage. To solve this problem, this letter presents a disturbance-adaptive robust internal-loop compensator (DA-RIC) to generate ideal interactive control performance from the backdrivable-servovalve-based system. The proposed control combines a robust internal-loop compensator structure (RIC) with an explicit disturbance estimator designed for asymptotic disturbance tracking, such that the controlled system provide stable and ideal dynamic behavior for impedance control, while completely compensating the disturbance effects. With the aid of a backdrivable servovalve, we show that the proposed control structure can be implemented based on a simplified nominal model, and the controller enables implementation without accurate knowledge of the target system parameters and disturbances. The performance and properties of the proposed controller are verified by simulation and experiments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.6
• /
• pp.2497-2503
• /
• 2012

In this study an educational robot for programming education was designed and implemented. The robot in this study is composed of hardware containing a sensor, a processor, and a motor driver circuit, software to control the educational robot, machine parts to manufacture the robot structure, and a teaching material containing educational contents and the manufacturing manual. This robot is characterized by direct programming without a computer, which gives no spatial restrictions on robot education and enables dynamic program education beyond limitations of the existing static computer program education since students' programming results are found in the robot's movements. User-centered functional commands, which make it possible to control the robot with simple knowledge concerning hardware and basic commands, were used to enable even students who first accessed a robot or computer program to make access with ease.