Need to develop human body's posture supervised robots, gave the push to researchers to think over dexterous design of exoskeleton robots. It requires to develop quantitative techniques to assess motor function and generate the command for the robots to act accordingly with complex human structure. In this paper, we present a new technique for the upper limb power exoskeleton robot in which load is gripped by the human subject and not by the robot while the robot assists. Main challenge is to find non-biological signal based human desired motion intention to assist as needed. For this purpose, we used newly developed Muscle Circumference Sensor (MCS) instead of electromyogram (EMG) sensors. MCS together with the force sensors is used to estimate the human interactive force from which desired human motion is extracted using adaptive Radial Basis Function Neural Network (RBFNN). Developed Upper limb power exoskeleton has seven degrees of freedom (DOF) in which five DOF are passive while two are active. Active joints include shoulder and elbow in Sagittal plane while abduction and adduction motion in shoulder joint is provided by the passive joints. To ensure high quality performance model reference based adaptive impedance controller is employed. Exoskeleton performance is evaluated experimentally by a neurologically intact subject which validates the effectiveness.

This paper proposes a method for path planning of high-degree of freedom (DOF) articulated robots with adaptive dimensionality. For an efficient path planning in high-dimensional C-space (configuration space), first we describe an adaptive body selection that selects the robot bodies and joints depending on the complexity of path planning. It means that the robot may use necessary DOF to achieve a path planning task. The adaptive body selection method builds the C-space with adaptive dimensionality for a sampling-based path planner. Next, by using the adaptive body selection, the adaptive Rapidly-Exploring Random Tree (RRT) algorithm is introduced, which incrementally grows RRTs in the adaptive dimensional C-space. And we show through several simulation results that the proposed method is more efficient than the original RRT-based path planner, which requires full-dimensional planning.

This study developed the Hanyang Exoskeleton Assistive Robot (HEXAR)-CR50 aimed at improving muscle strength of the wearer while transporting a load. The developed exoskeleton robot HEXAR-CR50 has 7 degrees of freedom (DOF) for one foot, 3-DOF for the hip joints, 1-DOF for the knee joints, and 3-DOF for the ankle joints. Through functional analysis of each human joint, two DOFs were composed of active joints using an electric motor developed in an under-actuated form with heightened efficiency. The rest of the DOFs were composed of passive or quasi-passive joints to imitate human joints. The control of the exoskeleton robot was based on the physical human-robot interaction. In order to verify the performance of the developed HEXAR-CR50, muscle activity was measured using electromyography, vGRF was measured using F-Scan sensor. The experimental results showed that %MVIC was reduced against the external load applied, while GRF had a decrement rate, compared with the external load when the exoskeleton was worn, which verified the performance in accordance with the development objective of load carrying. A muscle strength augment effect from the developed wearable robot was verified.

Need to develop human body's posture supervised robots, gave the push to researchers to think over dexterous design of exoskeleton robots. It requires to develop quantitative techniques to assess motor function and generate the command for the robots to act accordingly with complex human structure. In this paper, we focus on developing new technique for the upper limb power exoskeleton in which load is handled by the human subject and not by the robot. Main challenge along with the design complexity is to find the desired human motion intention and to develop an algorithm to assist as needed accordingly. For this purpose, we used newly developed Muscle Circumference Sensor (MCS) instead of electromyogram (EMG) sensors. MCS together with the load cells is used to estimate the desired human intention by which desired trajectory is generated. The desired trajectory is then tracked by passivity based adaptive control technique. Developed Upper limb power exoskeleton has seven degrees of freedom (DOF) in which five are passive and two are active. Active joints include shoulder and elbow, powered by electric motors and move in Sagittal plane while abduction and adduction motion in shoulder joint is provided by the passive joint. Performance of the exoskeleton is evaluated experimentally by a neurologically intact subject. The results show that after adjusting the motion intention recognition algorithm for the subject, the robot assisted effectively and the subject only felt nominal load regardless of the weight in hand.

In this paper, we propose and experimentally test a dynamic model-based force controller for the motion of upper limb exoskeleton robot. The system is composed of 3 degrees of freedom using an electrical actuator. This system is mainly controlled by the multi-axis force sensor signals. These are used to generate desired torques for driving the robot system. However, singularities exist when force signals in the Cartesian coordinate system are transformed to torques in the joint coordinate system. So we applied the damped least squares method. In handling loads, torque compensation regarding the weight of the object is required. Therefore, we installed the multi-axis force sensor at the robot end effector. It measures the interaction forces between the exoskeleton and the load. To compensate for the handling object, we used the static model. We performed control stability and load handling experiments to verify the effectiveness of the controller. With these experiments, we confirmed the effectiveness of the proposed controller.

This paper describes the compact design of a torque sensor using optical technique and its fabrication for wearable and quadruped robots. The torque generated can only be measured by placing torque sensor on each joint, which makes the joint bulky and heavy, adding extra load to be carried by robot. In this paper we proposed a compact and light weight design for the torque sensor. This sensor can measure torque of robots links by detecting torsion. The optical technique is used to detect angular displacement in the joints. The torque can be calculated by using torque and twist-angle relation. The proposed design is simulated by FEM software (ANSYS) and it shows successful measurements of the torque with a load capacity of 50 Nm, which is sufficient for the torque generated in wearable and quadruped robots joints. The designed optical torque sensor is manufactured by EDM (Electrical Discharge Machining). The optical torque sensor was calibrated and several experiments were conducted to ratify its feasibility with the wearable and quadruped robots.

An electric vehicles which is equipped with the in-wheel motors have an advantages in terms of control. For example, by generating different torques at the left and right wheels, the vehicle stability in cornering can be improved. This is called the direct yaw moment control method. In this paper, adaptive direct yaw moment control based on identification of yaw rate model is proposed for electric vehicles. In practical point of view, the incorrect yaw rate model causes the uncertainty to the reference yaw rate. Because the direct yaw moment is determined for tracking that uncertain reference yaw rate, the lateral motion of the vehicle cannot be desirable one. To solve this problem, the identification of the yaw rate model is considered. Therefore, the identified yaw rate model provides the yaw rate for the direct yaw moment method so that the vehicle follows the desired dynamic model. The simulation results show the possibility of the proposed methods.

In this study, an energy-efficient gait pattern and swing trajectory of the powered robotic exoskeleton was proposed through function distribution analysis and the dynamic-manipulability ellipsoid (DME). The exoskeleton has 3 DOF at each side, and it is possible to determine the minimum energy consumption of the joint torques under level-ground walking and stair ambulation conditions. To verify its feasibility and the effect of the proposed optimal gait pattern from the point view of the integrated system (human and exoskeleton), simulations were performed in the cases of walking on level ground and stair ascent/descent. Experiments such as on the metabolic cost of the human body with or without the assistance of the exoskeleton were conducted, and the power consumption of the exoskeleton was assessed, with the aim of improving the efficiency of the integrated system.

This paper presents the procedure and the results of the multi-objective optimization of the design of a seven degrees of freedom (7DOF) robot manipulator for better global performance, which pertains to the global conditioning, global manipulability, and structural length indices. The Taguchi method was used to reduce the time needed to analyze the global performance of the robot manipulator. Grey relational analysis was performed to deal with the multiple performances of the manipulator by converting multiple responses into a single response with a Grey relational grade. Analysis of variance (ANOVA) was done to analyze the effect of the link parameters on the performance of the robot manipulator, and to determine which link parameter affects the performance of the robot manipulator. The results of the optimization of the prototype robot manipulator and the comparison of the optimization results with those of an earlier study are presented herein.

We propose an algorithm of reliable detection of line for unmanned navigation of mobile robots using sensor fusion. To detect the distance and the angle between the robot and the line, we use a vision sensor system and a laser range finder (LRF). Each sensor system runs its own extended Kalman filter (EKF) to estimate the distance and orientation of the line. The vision system processes images being captured using well-known edge detection algorithms, and the LRF detects the line using the measurement of the intensity of the laser beam reflected. However, depending on the condition of the road and ambient light, each sensor gives us wrong measurement of the line or sometimes completely fails to detect it. To resolve such uncertainty, we develop a simple and easy-to-implement sensor fusion algorithm that uses weighted sum of the output of each EKF, and it gives us more reliable estimate of the distance and orientation of the line than each measurement/estimator system.

The will of humans with physical disabilities to move has found realization through the development of powered robotic exoskeleton. In this study, an energy-efficient gait pattern and swing trajectory of the powered robotic exoskeleton was proposed through function distribution analysis and the dynamic-manipulability ellipsoid (DME). To verify its feasibility and the effect of the proposed optimal gait pattern from the point view of the integrated system (human and exoskeleton), simulations were performed in the cases of walking on level ground and stair ascent/descent. Experiments such as on the metabolic cost of the human body with or without the assistance of the exoskeleton were conducted, and the power consumption of the exoskeleton was assessed, with the aim of improving the efficiency of the integrated system.

In this study, the concept of autonomous mobility is applied to a gait support mobile robot. The aim of the development of the service robot is to assist the elderly with gait assistant. This study proposes an ergonomic service robot design parameter. The gait assistant path pattern is derived from analysis of the elderly gait. A lever is installed in the AMR in order to measure both the pulling force and the leading force of the elderly. The path generation of the mobile robot is developed through consideration and analysis of elderly gait patterns. The ergonomic design parameters (dimensions, action scope and working space) are determined based on moving scope of the elderly. The gait assistant mobile robot was offered the elderly guide service and Internet service based on the ergonomic design parameters.

A path generation through use of a sensor platform is proposed. The sensor platform is composed of two electric motors which make panning and tilting motions. An algorithm for computing a real path and an obstacle length is developed by using a scanning method that controls rotation of the sensors on the platform. An autonomous robot vehicle (ARV) can recognize the given path by adapting this algorithm. A scanning algorithm for recognizing environments around the ARV is applied to the sensor platform. The path generation algorithm is composed of two parts: one is recognizing a path pattern; and the other is used to avoid an obstacle. An optimal controller is designed for tracking the reference path which is generated by recognizing the path pattern. Using the optimal controller and path generation algorithm, the ARV is constructed. Based on the results of actual experiments, this algorithm for an ARV proved sufficient for path generation by a small number of sensors and for a low cost controller using the sensor platform with a scanning method.

The micromanipulator is a device to enhance robot accuracy by allowing small, fast position corrections to be introduced near the end effector of a standard industrial robot. The objective of this paper is to discuss global issues for the design, manufacture, and implementation of this module. The kinematic and dynamic modeling method of the parallel mechanism is presented. The optimum geometric parameters for performing a given task are synthesized, based on the modeling simulation. Internal force, local maximum stress, and the deflection analyses are performed for critical loading cases to allow design of the hardware components. Design principles which address local and global objectives for the design of a micromanipulator are discussed, from the optimization point of view. The concept of designing a flexural joint to have low stiffness, low inertia, low friction, and no backlash while maintaining a kinematically sound system is discussed in detail. Finally, to eliminate the need for an external force sensor, an integral 6 DOF force sensing system would be included in the final design.>