Author name cluster

Chong-Won Lee

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

28 papers

1 author row

ICRA Conference 2004 Conference Paper

Implementation of Multi-functional Service Robots using Tripodal Schematic Control Architecture

Gunhee Kim
Woojin Chung
Mun Sang Kim
Chong-Won Lee

This paper describes the implementation of multi-functional service robots using the Tripodal schematic control architecture. Our strategy has two major advantages. First, the proposed architecture supports Petri net based formal description of tasks and error/fault handling schemes. Second, it provides intuitive and straightforward guidelines system for integration issues. We show reusability and scalability of the proposed architecture by giving two examples of our experience. First, we explain how to add a newly developed cleaning function to our robot system. Second, we introduce the implementation process of a newly developed guide robot Jinny. Most of the modules developed for former robots are used directly in the Jinny system. Experimental results clearly showed that the developed strategy is efficient and easy-to-use.

ICRA Conference 2004 Conference Paper

Integrated Navigation System for Indoor Service Robots in Large-scale Environments

Woojin Chung
Gunhee Kim
Mun Sang Kim
Chong-Won Lee

This paper describes an integrated navigation strategy for the autonomous service robot in large-scale indoor environments. It includes architecture of navigation system, the development of crucial navigation algorithms like map, path planning, and localization, and planning scheme such as error/fault handling. Major advantages of proposed navigation are as follows: 1) A range sensor based generalized scheme of navigation without modification of the environment. 2) Intelligent navigation-related components. 3) Framework supporting the selection of multiple behaviors and error/fault handling schemes. A experimental result shows the feasibility of proposed navigation system. The result of this research has been successfully applied to our three service robots in a variety of task domains including a delivery, a patrol, a guide, and a floor cleaning task.

ICRA Conference 2004 Conference Paper

Mobile Robot Navigation based on Direct Depth and Color-based Environment Modeling

Sung-Kee Park
Mun Sang Kim
Chong-Won Lee

This paper describes a new method for indoor environment mapping and localization with stereo camera. For environmental modeling, we directly use the depth and color information in image pixels as visual features. Furthermore, only the depth and color information at horizontal centerline in image is used, where optical axis passes through. The usefulness of this method is that we can easily build a measure between modeling and sensing data only on the horizontal centerline. That is because vertical working volume between model and sensing data can be changed according to robot motion. Therefore, we can build a map about indoor environment as compact and efficient representation. Also, based on such nodes and sensing data, we suggest a method for estimating mobile robot positioning with random sampling stochastic algorithm. With basic real experiments, we show that the proposed method can be an effective visual navigation algorithm.

IROS Conference 2003 Conference Paper

Safe arm with MR-based passive compliant joints and visco-elastic covering for service robot applications

Seong-Sik Yoon
Sungchul Kang
Seung-Jong Kim
Young-Hwan Kim
Mun Sang Kim
Chong-Won Lee

In this paper a safe arm with passive compliant joints and visco-elastic covering for human-friendly service robots is presented. The passive compliant joint (PCJ) is composed of a magneto-rheological (MR) damper and a rotary spring. The rotary spring gives the arm compliant property, but also it might be a source of vibration. Therefore the damper is introduced for damping effect and works as a rotary viscous damper by controlling the electric current according to the angular velocity of spring displacement. In an unexpected collision, the joints and cover passively operate and attenuate the applied collision force. The force attenuation property is being verified through collision experiments showing that the proposed passive arm overcomes limitations of an active compliant control approach.

ICRA Conference 2003 Conference Paper

Tripodal schematic design of the control architecture for the service robot PSR

Gunhee Kim
Woojin Chung
Mun Sang Kim
Chong-Won Lee

This paper describes a control architecture design and a system integration strategy for the autonomous service robot PSR (Public Service Robot). The PSR is under development at the KIST (Korea Institute of Science and Technology) for service tasks in public spaces such as office buildings and hospitals. The proposed control architecture is designed by tripodal frameworks, which are layered functionality diagram, class diagram, and configuration diagram. The tripodal schematic design clearly points out the way of integrating various hardware and software components. The developed strategy is implemented on the PSR and successfully tested.

IROS Conference 2002 Conference Paper

KAIST interactive bicycle racing simulator: the 2nd version with advanced features

Dong-Soo Kwon
Gi-Hun Yang
Youngjin Park
Sunmin Kim
Chong-Won Lee
Jae-Cheol Shin
Soonhung Han
Jonghwan Lee

This paper presents the KAIST interactive bicycle racing simulator system, which consists of a pair of bicycle simulators. The rider on the racing simulator experiences realistic sensations of motion, while being able to see the other bicycle simulator and having the audio-visual experience of riding in a velodrome or on the KAIST campus. The 2nd bicycle of the racing simulator system consists of a bicycle, a 4-DOF platform, a handlebar and a pedal resistance system to generate motion feelings; a real-time visual simulator a HMD and beam projection system; and a 3D sound system. The system has an integrating control network with an AOIM (Area Of Interest Management) based network structure for multiple simulators.

ICRA Conference 2001 Conference Paper

A New Exoskeleton-type Masterarm with Force Reflection based on the Torque Sensor Beam

Yoon Sang Kim
Sooyong Lee
Changhyun Cho
Mun Sang Kim
Chong-Won Lee

A new concept of the exoskeleton-type masterarm, composed of serial links, is introduced in the paper. To provide maximum range of human motion, several redundant joints are added to the serial links. In order to reduce the number of joints to be measured, kinematics of serial links was taken into consideration in design. Three measurable, controllable joints and three redundant free joints are used for the upper arm (shoulder), similarly to the forearm (wrist) while one measurable, controllable joint is used for the elbow. In particular, a torque sensor beam is designed for fine force reflection using the strain gauge. It detects the torque as well as its direction applied by the human operator, which allows the electric brake to be used as an actuator for force reflection. The electric brake constrains the joint movement so that the operator can feel the force. This electric brake outperforms the motor in terms of torque/weight ratio and makes the device light and compact. This masterarm measures the movement of the operator's arm precisely, and its can be used for teleoperation with a slave robot, or as a motion planner for an industrial robot.

IROS Conference 2001 Conference Paper

A passive multiple trailer system for indoor service robots

Jaehyoung Lee
Woojin Chung
Mun Sang Kim
Chong-Won Lee
Jeabok-Song

It is shown how a passive multiple trailer system is designed and controlled for practical applications. The main focus is reducing the trajectory tracking error and the scope of the paper is limited to the passive systems due to the cost and simplicity of the trailer mechanism. Three kinds of passive trailers are introduced, and then the analysis of path tracking performance is carried out, in order to show that the proposed off-hooked trailer is advantageous in a practical sense. Stability, issues are discussed with constant reference velocity. Numerical simulation results and experimental results are presented.

ICRA Conference 2001 Conference Paper

KAIST Interactive Bicycle Simulator

Dong-Soo Kwon
Gi-Hun Yang
Chong-Won Lee
Jae-Cheol Shin
Youngjin Park
Byungbo Jung
Doo Yong Lee

This paper presents key technologies and system integration issues of the KAIST interactive bicycle simulator. The rider on the bicycle feels the motion and has the visual experience as if he/she is riding in the campus of the Korea Advanced Institute of Science and Technology. The simulator consists of a bicycle, a Stewart platform, a magnetorheological handle, a pedal resistance system to generate motion feelings, a real-time visual simulator and projection system, sub-controllers and an integrating control network.

IROS Conference 2000 Conference Paper

Regrasp planner using look-up table

Kyoungrae Cho
Mun Sang Kim
Chong-Won Lee
Jae-Bok Song

Regrasping, given initial and final pose of the target object, is a construction of sequential transition of object poses that are compatible with two poses in the point of grasp configuration. This paper presents a novel approach for solving the regrasp problem. The approach consists of a preprocessing and planning stages. Preprocessing, which is done only once for a given robot, generates a look-up table which has information of kinematically feasible task space of end-effector through all the workspace. Then, using the table, planning automatically determines possible intermediate location, pose and regrasp sequence leading from the pick-up to put-down grasp. Experiments show that the approach presented is complete in the total workspace. The regrasp planner was combined with the existing path.

IROS Conference 1999 Conference Paper

A new exoskeleton-type masterarm with force reflection: controller and integration

Sooyong Lee
Jangwook Lee
Woojin Chung
Mun Sang Kim
Chong-Won Lee
Mignon Park

For robot teleoperation, a lot of research has been done to control the slave robot from a remote site using a masterarm. The concept of a distributed controller architecture for the masterarm is introduced in the paper. To reduce possible non-uniform time delay and to have higher position command update rate, the host controller with distributed satellite controllers is developed. Each satellite controller measures the corresponding joint angle, while the host controller performs initial calibration, inverse kinematics calculation, and position commands generation. The host controller and the satellite controllers are networked via a SPI (serial peripheral interface) protocol. For force feedback, the host controller solves the joint torque relations based on the kinematics of the masterarm and the satellite controller controls each joint's torque. This distributed controller greatly reduces calculation and control loads and makes the electrical wiring very simple. In order to measure finger movement of the operator, the master hand is developed using infrared light. A similar slave satellite controller for this master hand is interfaced to the host controller via a SPI network. For teleoperation of the KIST humanoid robot which has two arms and two hands, the masterarm controller with one host controller and 16 satellite controllers is implemented. Force feedback with less than 2 msec update rate is achieved. This masterarm/hand is also integrated with a graphic model instead of using the slave robot. The experimental results show the performance of the distributed controller.

ICRA Conference 1999 Conference Paper

Adaptive Accommodation Control for Complex Assembly: Theory and Experiment

Kungchul Kang
Mun Sang Kim
Chong-Won Lee
Kyo-Il Lee

An adaptive accommodation control for complex assembly (CA) is presented. The CA is defined as a task whose assembled parts have complex geometry including concavity. The concept of the adaptive accommodation, which is inspired by the insertion operation of a blindfold human, is to adaptively change the accommodation property depending on the sensed contact wrench and the current target twist. Both the bounded wrench condition and the target approachability condition can be satisfied simultaneously by applying the adaptive accommodation control law. By using the convex optimization technique, an optimum target approaching twist with adaptive accommodation properly can be determined at each instantaneous contact state as a global minimum solution. A new adaptive accommodation control law, which is independent of part geometry, is developed without motion planning nor contact analysis procedure. A VME-bus based real-time control system is built to various CA tasks experiments.

ICRA Conference 1999 Conference Paper

The Distributed Controller Architecture for a Masterarm and Its Application to Teleoperation with Force Feedback

Sooyong Lee
Jangwook Lee
Dae-Sung Choi
Mun Sang Kim
Chong-Won Lee

For robot teleoperation, many researches have attempted to control the slave robot from remote site using a master arm. A new concept of the distributed controller architecture for the master arm is introduced. To reduce possible non-uniform time delay and to have higher position command update rate, the host controller with the distributed satellite controllers are developed. Each satellite controller measures the corresponding joint angle, while the host controller performs initial calibration, inverse kinematics calculation, and position commands generation. The host controller and the satellite controllers are networked via the SPI (serial peripheral interface) protocol, with maximum speed of 5Mbps. For force feedback, the host controller solves the joint torque relations based on kinematics of the master arm, and the satellite controller controls each of the joint torque. This distributed controller greatly reduces calculation and control loads and makes the electrical wiring very simple.

IROS Conference 1999 Conference Paper

Three-dimensional pose determination for a humanoid robot using binocular head system

Hong-Jae Kim
Bum-Jae You
Gregory D. Hager
Sang-Rok Oh
Chong-Won Lee

There has been much interests on three-dimensional pose estimation of an object since there are a lot of robotic applications such as intelligent robotic assembly and/or vision-guided control of a humanoid or human-friendly robot. In this paper, there are proposed a simple and fast stereo matching algorithm for real-time robotic applications and an improved scheme for feature matching using three-dimensional information by adopting backprojection as a feedback element measuring the degree of feature matching. The degree of feature matching is determined by checking existence ratio of each feature point in real images after back-projecting an object model into image plane. The proposed pose determination algorithm is applied for a humanoid robot in KIST, whose name is CENTAUR, successfully and determine the pose of several polyhedral objects using 3D information of vertexes on the outline of an object in image plane.

IROS Conference 1999 Conference Paper

Two-arm cooperative assembly using force-guided control with adaptive accommodation

Jong-Dho Choi
Sungchul Kang
Mun Sang Kim
Chong-Won Lee
Jae-Bok Song

A two-arm cooperative assembly (or insertion) algorithm is proposed. As a force-guided control method for the cooperative assembly, the adaptive accommodation controller is adopted since it does not need any complicated contact state analysis nor depends on the geometrical complexity of the assembly parts. Also, the RMRC (resolved motion rate control) method using a relative Jacobian is used to solve inverse kinematics for two manipulators. By using the relative Jacobian, the two cooperative redundant manipulators can be structured as a new single redundant manipulator. The two arms can perform a variety of insertion task by a relative motion between their end effectors. A force/torque sensing model, using an approximated penetration depth calculation algorithm is developed and used to compute a contact force/torque in the graphic assembly simulation. By using the adaptive accommodation controller and the force/torque sensing model, a spatial cooperative assembly tasks have been successfully executed in the graphic simulation. Finally, through a cooperative assembly task experiment using a humanoid robot, CENTAUR, which inserts a spatially bent pin into a hole, its feasibility and applicability are verified.

ICRA Conference 1998 Conference Paper

A Control Architecture to Achieve Manipulation Task Goals for a Humanoid Robot

Young-Jo Cho
Jung Min Park
Jaehyun Park
Sang-Rok Oh
Chong-Won Lee

Focusing on the manipulation tasks to be executed by humanoid robots, principal requirements which are to be satisfied by hardware/software of the control system are considered. In order to meet the requirements, a novel type of hardware structure and software architecture is proposed. Since the target humanoid robot consists of multiple subsystems such as a central controller for brain, a vision controller for eye, and five motion sub-controllers for two arms, two hands, one spine, the on-board hardware control system is designed to have a distributed control structure connected by pseudo real-time Ethernet interfaces. A goal-achieving software architecture is also proposed which meets the requirements of semi-autonomy, reactivity, expandability, and object-orientedness. Specifically, in order to achieve reactivity, a coordination method is proposed to configure three kinds of executive modules, primitive module, flow-control module, and goal module, which have multiple exit states. The control architecture proposed has been implemented for performing toy-block assembly tasks on a humanoid robot as well as on the graphic simulator.

ICRA Conference 1998 Conference Paper

A Target Approachable Force-Guided Control for Complex Assembly

Kungchul Kang
Mun Sang Kim
Chong-Won Lee
Kyo-Il Lee

Presents a target approachable force-guided control for complex assembly. A complex assembly (CA) is a task which deals with complex shaped parts including concavity or whose environment is so complex that unexpected contacts occur during insertion. CA tasks are encountered frequently in manufacturing automation and robot applications. To make CA successful, both the bounded wrench condition and the target approachability condition should be satisfied simultaneously during insertion. The former can be satisfied by properly designing the damping control parameters, and the latter by determining an admissible twist minimizing the difference between the current and the target direction. By applying the convex optimization technique, the target approachable twist can be determined at each instantaneous contact state as a global minimum solution. Incorporated with an admissible perturbation method, a new CA algorithm using only the sensed resultant wrench and the target direction vector is developed without motion planning nor contact kinematic analysis procedure, which requires the geometry of the part and the environment. As a result of the simulation for the task of inserting a T-shaped object involving concavity, its feasibility and applicability have been verified The task of inserting a T-shaped part into a slot with a tight tolerance was successfully executed by the proposed target approachable force-guided controller.

IROS Conference 1998 Conference Paper

An unified approach to teleoperation: human and robot integration

Sooyong Lee
Dae-Seong Choi
Mun Sang Kim
Chong-Won Lee
Jae-Bok Song

To increase the accuracy and the reliability of teleoperation, close interaction between human and the slave robot is required. Korea Institute of Science and Technology (KIST) is developing a Humanoid robot, which has two 9-DOF arms, two 4-DOF hands, a 3-DOF waist and a 2-DOF neck. An automatic path planner which takes advantage of redundancy is also developed, but it requires huge computational power and time. For tasks which are very complex, or interacting with environments, robot path can be generated very easily and accurately by human teaching, hence the automatic path planner is not required. Using sensors, human motion is analyzed and converted to robot joint angles. For tasks interacting with unknown environment, teleoperation with force feedback is more useful. A simple platform-type master arm is designed based on the kinematic analysis of human. For force reflection, the pneumatic actuators are used. This device is integrated with KIST Humanoid robot as well as graphic simulator, so that the master arm can be used for teaching the robot or as the virtual reality device integrated with the graphic simulator. Force reflecting master hand is also developed. These force reflecting master arm and hand are very light and compact so that a human can wear easily while he feels the same force as the robot does while giving position command to the slave robot. In addition to master arm/hand, visual information is feedback to human through HMD for higher interaction. Therefore, a new way of integration of human and the robot is developed.

ICRA Conference 1998 Conference Paper

Design of a Force Reflecting Master Arm and Master Hand Using Pneumatic Actuators

Sooyong Lee
Sangmin Park
Mun Sang Kim
Chong-Won Lee

A lot of researches have been done in the teleoperation field. In order to control a robot from remote site, simple position teaching devices were developed followed by the advanced force feedback devices. Most of the force feedback master devices are as big as the slave robot and equipped with heavy actuators. A new teleoperation device is presented in this paper. A simple exo-skeleton type master arm is designed based on the kinematic analysis of the human arm. For force reflection, pneumatic actuators are used. This device is integrated with KIST Humanoid robot as well as graphic simulator, so that the master arm can be used for teaching the robot or as the virtual reality device integrated with the graphic simulator. A force reflecting master hand was also developed with similar design to the master arm. These force reflecting master arm and hand are very light and compact so that a human can easily wear while he feels the same force as the robot does while giving position command to the slave robot.

ICRA Conference 1998 Conference Paper

High Speed Tracking Control of Stewart Platform Manipulator via Enhanced Sliding Mode Control

Nag-In Kim
Chong-Won Lee

High speed tracking control of a 6-6 Stewart platform manipulator is performed by employing an enhanced sliding mode control with reduced manipulator dynamics when the manipulator is assumed to be operated on a low frequency planar motion unit. The high-performance tracking control strategy normally requires the complex full dynamics of 6-6 Stewart platform manipulator. The dynamics becomes even more complicated in the presence of the base motion of the manipulator, requiring additional sensors for measurement of the base motion. It is shown that enhanced sliding mode control implemented with perturbation compensation and reaching phase alleviation functions can effectively remove the use of the complex full dynamics and the additional sensors in the control system for high performance tracking control of the Stewart platform manipulator under the effects of virtual base motion.

ICRA Conference 1998 Conference Paper

Optimal 3D Viewing with Adaptive Stereo Displays

Sukhan Lee 0001
Sookwang Ro
Jong-Oh Park
Chong-Won Lee

An optimal projection of stereo images onto an HMD screen is presented, such that the viewer can observe a real-world object or local scene of his/her interest in 3D, with the feeling of desired depth and scaling, under the minimum distortion. Taking the object or local scene of viewer's focal point as that of his/her interest, the proposed 3D viewing is intended to march the characteristics of human vision. The optimal projection is done by determining the scaling factor and horizontal displacement of the original stereo images as a function of the convergence angle of the stereo camera. In this paper, we put an emphasis on the verification of the proposed optimal 3D viewing method through experimentation.

IROS Conference 1998 Conference Paper

Reference adaptive impedance control: a new paradigm for event-based robotic and telerobotic control

Sukhan Lee 0001
Ming-Feng Jean
Jong-Oh Park
Chong-Won Lee

A new paradigm of event-based robotic and telerobotic control, referred to as the reference adaptive impedance control, is presented for partially constrained robotic and telerobotic tasks under uncertain or unknown environmental constraints. The reference adaptive impedance control determines the desired next state adaptively to follow the optimal path from the current state, where the optimal path is generated with the environmental constraints updated through time. The embedded impedance control provides a mechanism for collecting more complete information on the environment. The reference adaptive impedance control also serves as a powerful tool for implementing shared control in teleoperation. A case study of robotic and telerobotic soil trenching is given with peg-hole insertion experiment.

ICRA Conference 1997 Conference Paper

A compliant motion control for insertion of complex shaped objects using contact

Sung C. Kang
Yong K. Hwang
Mun S. Kim
Chong-Won Lee
Kyo-Il Lee

This paper presents a compliant control method for insertion of complex objects with concavities. Most work on robot assembly using compliant motion control focuses on overcoming jamming conditions for simple peg-in-hole problems, and cannot be used for complex shapes frequently encountered in assembly applications. When an object is being inserted into a hole or slot with a small clearance, a contact path issued to compensate for uncertainties. When the object shape is complex, however, the contact state changes several times and severely, making compliant control difficult. Our algorithm is capable of controlling compliant motion in spite of changing contact states. During the execution of a nominal motion plan, it computes the actual position of the contact point from the force/torque sensor reading using a contact localization algorithm. It then dynamically updates the center of compliance to the computed contact point, and minimizes the chance of jamming and unwanted collisions. The control scheme has been implemented on hardware and tested on the task of inserting a T-shape into a C-shape involving a very tight tolerance. The insertion motion was accomplished by a sequence of 2 translational and 1 rotational compliant motions, and successfully executed by the proposed compliant motion controller.

IROS Conference 1997 Conference Paper

Human computer competition in game situation: motion planning for boxing

Sang M. Park
Yong K. Hwang
Sooyong Lee
Sungchul Kang
Kyungrae R. Cho
Young S. Han
Mun S. Kim
Chong-Won Lee

This paper presents a motion planner for robots in a game situation, in which the agents involved have conflicting goals. More specifically, a human-computer boxing game system is developed in a graphical environment. One boxer is controlled by a human through a motion tracking system, while the other is controlled by a motion planning algorithm. The planner has a defensive and an offensive strategies. The defensive strategy tries to move one of the forearms between the opponent's fist and its body, while the offensive strategy locates an exposed part of the opponent's body and throws a punch at it. To achieve an interactive operation, the motion planner considers only kinematic and geometric constraints during the search. This project is also aimed at integrating a planner with all actual robot, and investigating associated technological bottlenecks.

IROS Conference 1997 Conference Paper

Reference adaptive impedance control and its application to obstacle avoidance trajectory planning

Sukhan Lee 0001
Soo-Yeong Yi
Jong-Oh Park
Chong-Won Lee

A new paradigm of event-based robotic control, called reference adaptive impedance control, is presented for partially constrained robots under uncertain or unknown environmental constraints. The reference adaptive impedance control determines the desired next state adaptively in such a way as to follow the optimal path from the current state, where the optimal path is generated with the environmental constraints updated through time. The embedded impedance control provides a mechanism for collecting more complete information on the environment. An application to obstacle avoidance trajectory planning is given with computer simulations.

IROS Conference 1996 Conference Paper

Complete motion planner for time-varying environments

Yong K. Hwang
Pang C. Chen
Chong-Won Lee
Mun S. Kim

This paper presents a complete motion planner in three-dimensional changing environment. The robot is either a manipulator or a rigid object that translates and rotates, while obstacles are polyhedra translating and rotating along known trajectories. The motion planner is based on the SANDROS search strategy, which uses a hierarchical, multi-resolution representation of the product space of the time and the configuration space. A solution is found by generating a candidate sequence of subgoals and subsequently computing collision-free path along the sequence. For changing environments it is the first planner for non-point robots that is efficient and guarantees a solution. This planner can control the trade-offs between the computation resource and algorithmic completeness/solution path quality, and thus can fully utilize the available computing power. This algorithm is useful for navigation of mobile robots and submarines, or motion planning of multiple robots by regarding other robots as moving obstacles.

IROS Conference 1996 Conference Paper

Optimal 3D viewing with adaptive stereo displays for advanced telemanipulation

Sukhan Lee 0001
Srinivasan Lakshmanan
Sookwang Ro
Jong-Oh Park
Chong-Won Lee

A method of optimal 3D viewing based on adaptive displays of stereo images is presented for advanced telemanipulation. The method provides the viewer with the capability of accurately observing a virtual 3D object or local scene of his/her choice with minimum distortion. The viewer is allowed to define a virtual 3D object or local scene at a desired depth as a scaled version of a real 3D object or local scene which he/she wants to focus on. The key result is an algorithm which determines in real-time the optimal parameter values associated with stereo imaging and image projection on a video screen. The selected parameter values implement the optimal stereo viewing adapted to the viewer's focus of attention. Simulation results are shown.

IROS Conference 1995 Conference Paper

A compliance control strategy for robot manipulators using a self-controlled stiffness function

Sang-Rok Oh
Ho-Chan Kim
Il Hong Suh
Bum-Jae You
Chong-Won Lee

A compliance control strategy is proposed by using a new type of self-controlled stiffness function, where no explicit wrist force/torque sensor is employed. Specifically, the stiffness gain is given as the exponential function of the error between virtually given desired trajectory and actual trajectory, where virtual desired trajectory is designed to be inside the surface of the object to be compliance-controlled. And, a motion speed scheduling technique is also proposed to avoid serious damages due to lack of environmental knowledge and to minimally maintain the task performances. It is experimentally shown that the proposed control method is useful for various manipulator motion types such as path following, initial contact with soft impact and force regulation during contact.