In the aftermath of the financial crisis of 2008, while numerous members of the general public lost their homes and jobs, many of the largest banks held responsible for the crisis have been successfully rescued by bailouts. In this paper, through the analysis of income inequality, unemployment, tax cuts, and bailouts, we show that the interests of the general public are different from the interests of politicians and bankers. While the small elite group of politicians and bankers could set the deregulation policies with inordinate power based on full information, most people were ignorant and unconcerned about the policies, and hence did not oppose them. Specifically, we model the credit change in the financial markets of the United States by a finite state machine, and design three local supervisors representing three groups with different interests. It is then shown that the deregulation policies were adopted according to the difference of the supervisors' powers.

This paper deals with the adaptive backstepping hovering control for a quadrotor with model parameter uncertainties. In this paper, the backstepping based technique is utilized to design a nonlinear adaptive controller which can compensate for the motor thrust factor and the drag coefficient of a quadrotor. First, the quadrotor nonlinear dynamics is derived using Newton-Euler formulation. In particular, we use the ${\pi}/4$ shifted coordinate for x- and y-axis of a quadrotor. Second, an adaptive backstepping based attitude and altitude tracking control method is presented. The system stability and the convergence of tracking errors are proven using the Lyapunov stability theory. Finally, the simulation results are given to verify the effectiveness of the proposed control method.

This paper introduces an adaptive anti-sway tracking control algorithm for container cranes with unknown payloads and friction between the trolley and the rail. If the friction effects in the system can be modeled, there is an improved potential to design controllers that can cancel these effects. The proposed control improves the sway suppressing and the positioning capabilities of the trolley and hoisting against uncertain payload and friction. The variable structure controls are first designed based on a class of feedback linearization methods for the stabilization of the under-actuated sway dynamics. The adaptation mechanism are then designed with parameter estimation of unknown payload and friction compensation for the trolley and hoisting, based on Lyapunov stability methods for the accurate positioning and fast attenuation of trolley oscillation due to frictions in the vicinity of the target position. The asymptotic stability of the overall closed-loop system is assured irrespective of variations of rope length. Simulations are shown under various frictions and external winds in the case of no priori information of payload mass.

In mechatronic systems using electric signals to drive control systems, driving signals including the frequency band of the unwanted signals, such as resonant frequencies and noise frequencies, can affect the accuracy of the controlled system and can cause serious damage to the system due to the resonance phenomenon of the mechatronic system. An LOS (Line of Sight) control unit is used to automatically rotate the gimbal system with a video imaging system generally mounted on modern aerial vehicles. However, it still suffers from natural frequency variation problems due to variations of operational temperature. To prevent degradation in performance, this paper proposes an adaptive filtering technique based on real-time noise analysis and adaptive notch-filtering for LOS control systems, and verifies how our proposed method maintains the LOS stabilization performance. Additionally, this filtering technique can be applied to the image noise filtering of the video imaging system. It is designed to reduce image noises generated by switching circuits or power sources. The details of design procedures of the proposed filtering technique and the experiments for the performance verification are described in this paper.

In this paper, we propose an SPDR (Smith Predictor for Disturbance Reduction) scheme to improve the temperature control by reduction of the disturbance in ROT process with measurement delay. The proposed controller is a combination of Astrom's modified Smith predictor with a disturbance reduction controller and a grey predictor. The grey prediction is used to calculate the inverse of the measurement delay and to predict future variations and tendencies of system output. The simulation results demonstrate the successful performance of the proposed disturbance reduction controller and enhance the robustness of the proposed control scheme.

Machine vision inspection systems have replaced human inspectors in defect inspection fields for several decades. However, the inspection results of machine vision are often affected by small changes of illumination. When small changes of illumination appear in image histograms, the influence of illumination can be decreased by transformation of the histogram. In this paper, we propose an enhanced histogram matching algorithm which corrects distorted histograms by variations of illumination. We use the resolution resizing method for an optimal matching of input and reference histograms and reduction of quantization errors from the digitizing process. The proposed algorithm aims not only for improvement of the accuracy of defect detection, but also robustness against variations of illumination in machine vision inspection. The experimental results show that the proposed method maintains uniform inspection error rates under dramatic illumination changes whereas the conventional inspection method reveals inconsistent inspection results in the same illumination conditions.

In this paper, a new haptic device is proposed for the teleoperation, which can recognize the invisible environment of a mobile robot. With this new device, it is possible for the user to identify the location of an obstacle and to avoid it. The haptic device has been attached on the top of a joystick so that the user can remotely control the mobile robot to avoid the obstacles which are recognized by the ultrasonic sensors. Also, the invisible environment is recognized more accurately overlapping the data from the ultrasonic sensors. There are five vibration motors in the haptic device to indicate the direction of the obstacle. So the direction of the obstacle can be recognized by the vibration at the finger on each vibration motor. For various situations and surrounding environments, experiments are performed using fuzzy controller and overlapping ultrasonic sensors. The results demonstrate the effectiveness of the proposed haptic joystick.

Robots used for pipe inspection have been studied for a long time and many mobile mechanisms have been proposed to achieve inspection tasks within pipelines. Localization is an important factor for an inpipe robot to perform successful autonomous operation. However, sensors such as GPS and beacons cannot be used because of the unique characteristics of inpipe conditions. In this paper, an inpipe localization algorithm based on elbow detection is presented. By processing the projected marker images of laser pointers and the attitude and heading data from an IMU, the odometer module of the robot determines whether the robot is within a straight pipe or an elbow and minimizes the integration error in the orientation. In addition, an off-line positioning algorithm has been performed with forward and backward estimation and Procrustes analysis. The experimental environment has consisted of several straight pipes and elbows, and a map of the pipeline has been constructed as the result.

In this paper, we introduce an intelligent robotic arc welding system which exploits sensors like as LVS (Laser Vision Sensor), Hall effect sensor, voltmeter and so on. The use of industrial robot is saturated because of its own limitation, and one of the major limitations is that industrial robot cannot recognize the environment. Lately, sensor-based environmental awareness research of the industrial robot is performed actively to overcome such limitation, and it can expand application field and improve productivity. We classify the sensor-based intelligent arc welding robot system by the goal and the sensing data. The goals can be categorized into detection of a welding start point, tracking of a welding line and correction of a torch deformation. The Sensing data can be categorized into welding data (i.e. current, voltage and short circuit detection) and displacement data (i.e. distance, position). This paper covers not only the explanation of the each category but also its advantage and limitation.

This paper proposes a tip-over detection method for a mobile robot using a support inscribed circle defined as an inscribed circle of a support polygon. A support polygon defined by the contact points between the robot and the terrain is often used to analyze the tip-over. For a robot moving on uneven terrain, if the intersection between the extended line of gravity from the robot's COG and the terrain is inside the support polygon, tip-over will not occur. On the contrary, if the intersection is outside, tip-over will occur. The terrain is detected by using an RGB-D sensor. The terrain is locally modeled as a plane, and thus the normal vector can be obtained at each point on the terrain. The support polygon and the terrain's normal vector are used to detect tip-over. However, tip-over cannot be detected in advance since the support polygon is determined depending on the orientation of the robot. Thus, the support polygon is approximated as its inscribed circle to detect the tip-over regardless of the robot's orientation. To verify the effectiveness of the proposed method, the experiments are carried out using a 4-wheeled robot, ERP-42, with the Xtion RGB-D sensor.

The humanoid robot, DRC-HUBO is developed from the KHR (KAIST Humanoid Robot) series to meet the requirements of the DARPA Robotics Challenge. DARPA Robotics Challenge was a competition to develop semi-autonomous humanoid robot so that dispatched in dangerous environments in place of humans like the Fukushima nuclear accident. In this paper, we introduce DRCH-UBO briefly and a methodology to remove debris blocking an entryway. The methodology includes inverse kinematics for DRC-HUBO and stabilization controller based on ZMP. Proposed inverse kinematics is robust, and pelvis-related tasks improve the manipulability and workspace of the arms. The controller improves the damping characteristic of the system and mitigates the instability during removal of debris. For given position and orientation of the debris, DRC-HUBO generates motion to reach the debris and lift up while stabilizing itself. Many experimental results verify our proposed methodology.

The ability to overcome obstacles is necessary for field robots for various applications including the ability to climb stairs. While much research has been performed focusing on overcoming obstacles, the resulting robots do not have sufficient ability to overcome obstacles such as stairs. In this research, the purpose is to overcome relatively large obstacles by flipping locomotion through the modification of the stair climbing robotic platform of the previous research. We propose two scenarios to overcome large obstacles: a rear wheel driving system and an elevation system using a ball screw. The research is performed based on static analyses on obstacle-climbing. As the simulation results indicate, we determined the optimal posture of the robot for climbing obstacles for rear wheel driving. Also, an elevation system is analyzed for obstacle climbing. Between the two scenarios an elevation system is determined to reduce the operating torque of the actuator, and the prototype was recently assembled. The climbing ability of the robotic platform is verified. We expect the application area for this robotic platform will be in accident areas of nuclear power plants.

In this paper, an effective repeat-back jamming (RBJ) mitigation scheme known assuccessive repeat-back jamming cancellation (SRC) is proposed for the utilization of the successive interference cancellation (SIC) algorithm which is used to mitigate the near-far effect and the multiple-access interference for code division multiple-access communication systems. The proposed scheme uses a combined pseudo-random noise (C-PRN) signal from the estimated major parameters of RBJ signals. To evaluate the performance of the proposed scheme, the root mean squared (RMS) code tracking errors are shown according to the standard deviation of the parameter estimation errors of an RBJ signal, and using the well-known major parameters estimation schemes with a C-PRN signal through Monte-Carlo simulation.

In this paper, a new zone radius determination algorithm is proposed for a nature-inspired routing protocol that emulates the foraging behavior of bees based on their ability to find an optimal route from nectar sites. Instead of changing the radius of nodes one-hop by one-hop, the proposed algorithm alters the radius of nodes as gaps of another radius and adapt quickly to network conditions. The simulation results show that the proposed algorithm has higher efficiency compared with existing studies in an aspect of computational complexity and end-to-end delay.