Applied Mechanics and Materials Vols. 541-542

Abstract: Hyper-redundant robot (HRR) manipulators are useful at navigating convoluted paths, but conventionally complicated to control. The control of a hyper-redundant manipulator is complex due to its redundancy. In this paper, a simple but effective control algorithm for obstacle avoidance is proposed. The algorithm derives a collision free path around known obstacles so that the end-effector of a variable length hyper redundant robot (VHRR) is able to reach the target location following the path without hitting the obstacles. The algorithm can be grouped into two tasks to drive the end-effector along the collision free trajectories: first, solve the inverse kinematics without disregarding the existence of obstacles in the system; and second, fit the manipulator to the respective prescribe trajectories. This method has the capability to allow VHRR maneuver within its workspace without penetrating to the neighboring obstruction. Further, this method is very effective in the sense that it forms a nice coil profile avoiding zig-zag configuration, and thus eliminates sharp turn on the robot. The performance of a VHRR was tested through simulation to demonstrate the effectiveness of the proposed method. The approach succeeded in delivering the path that avoids obstacle.

Abstract: Multi-robot System (MRS) for intelligent creel consists of automatic winder, transferring, transiting and supplying robot and provides the possibilities of the flexibility and automation of textile industry workshop. Based on the principle of centralized management and distributed control the system and designs distributed control system (DCS) of Multi-robot for intelligent creel based on CAN bus. Layered architecture is established consisting of main control layer, communication layer, synchronous coordination layer and execution layer. According to the complex characteristics of the system, a synchronous controller is designed to allocate and coordinate task,improving the intelligence of the system. Coordination controller also realizes function of CAN Bridge.

Abstract: Group conversation, one form of social activities, plays main roles to train and rehabilitate cognitive function as well as improve emotional states in older adults. It has been mainly utilized for healthy older adults. This paper proposes a robot that warms up group conversations of older adults by reusing or repeating speech statements, which are played successfully to activate group conversations of older adults previously. A novel group conversation technique called the "coimagination" method for preventing mild cognitive impairments and dementia, was used for collecting and reusing conversation data. Two types of group conversation experiments were conducted among older adults. 1) All participants who were human in coimagination sessions, present their original stories with pictures according to selected topic. 2) One of participants in coimagination sessions was a robot, which presents the reproduced interesting stories. These reproduced stories were collected and implemented into the robot in advance. We analyzed the data by the frequency of evoked laughter in each topic and in all participants. The reproduced stories presented by the robot created more laughter than the original stories presented by human. The robot successfully elicited more laughter than the human participants. Based on these results, we found that the robot successfully enlivened group conversation through evoking laughter.

Abstract: The purpose of this study is to develop the architectural system design of the Six Channels Compact Fuzzy Logic Controller (SCC-FLC) ready to be embedded into the FPGA (Field Programmable Gate Array) for joints of arm robot's manipulator. The FPGA based system design of this study could controlled independently six servo of arm robot manipulators to reduce workload of computer system. The method of this study divided into four steps. The first step, the FLC-P (Fuzzy Logic Controller Processor) block module of single channel C-FLC (Compact Fuzzy Logic Controller) on the previous study is redesigned in architectural system design by adding lots of block modules using multiplexing method. The second step, the module interconnections of system architecture are designed by defining some of inputs and output ports. The third step, the specific function of block modules about working processes is determined based on the definition of input and output ports. The fourth step, sequences of multiplexing processes are determined based on the algorithm of FLC, thus the total processing time of SCC-FLC could be estimated from architectural system design. Architectural system design of SCC-FLC requires external chips are 12bit ADC MAX-186 chip and 12bit DAC MAX-3203 of six chips. The block modules of SCC-FLC are FLC-P, LUT-MBFs (Look Up Table of Membership Function), ADC-I (Analog to Digital Converter Interface), DAC-I (Digital Analog Converter Interface), ECEG (Error and Change Error Generators), SPL (Set Point Latchs) and TAC (Time And Control). The total processing time of SCC-FLC by estimation is 256.2 µS or sampling frequency of 3.907KHz using clock frequency of 100MHz.

Abstract: This study is about the design and control of waterproof 4-axis robot arm that allows underwater operation. To enhance the load capacity of the robot arm, a module-type gravity compensator (GC) is designed and applied to each joint. The dynamic equation of the robot arm was set up and analyzed by including frictional force of waterproof apparatus and compensating force of the GC. A SMC was designed and its performance was tested through simulation to track a target trajectory despite disturbance such as friction in joints.

Abstract: More and more dual arm robots with redundant manipulator are introduced in industrial fields. Here we focus on this special structure with 7-DOF redundant manipulator, an exhibit analytical and optimal concept was proposed. The formula derivations of inverse kinematics showed that when the redundant joint angle has been obtained, the remaining six joint angles can be derived analytically, and there are eight sets of inverse solution for one giving redundant joint angle. Reversed thinking the joint movement habits, patterns, and frequency of human arm operations, an optimal concept was presented to gain a real time computational efficiency of a direct inverse solution while also achieving the purpose of application.

Abstract: The transfer robot using for small flat panel display manufacturing process is developed. Requirement for transfer robot such as minimization of deflection and lateral vibration is achieved by enhancement of stiffness of arm and hand by finite element analysis. Arrangement of reduction gear is designed to increase stiffness and decrease position error at the end point of arm. The repeatability of arm is improved by applying the precision control method. Experiment is conducted to verify the performance of developed transfer robot. From the performance test, developed transfer robot has repeatability of under ±0.1mm, deflection of 2mm, straightness of under ±1.5mm, and velocity of 1500mm/sec.

Abstract: Robotic exoskeleton system has been found to be an active area of study which being used in human power augmentation, human power assistance, robotic rehabilitation, and haptic interaction in virtual reality developed in recent robotic research. In recent years, the application of robotic exoskeleton has become more prominent as to provide alternative solutions for physically less incapable people (PLIP) support in their daily movements. Most common difficulties faced by PLIP are in sit-to-stand, ascending and descending staircases. Unlike industrial robots, the robotic exoskeleton systems need to consider a special design because they directly interact with human user. In the mechanical design of these systems, human and robotic suitable kinematics, wearer safety, human user comfort wearing, low inertia, and adaptability should be especially considered. Controllability, responsiveness, flexible and smooth motion generation, and safety should especially be considered in the controllers of exoskeleton systems. Furthermore, the controller should generate the motions in accordance with the human motion intention. This paper briefly reviews the lower-limb robotic exoskeleton systems. In the short review, it is focused to identify the brief history, basic concept, challenges, and future development of the robotic exoskeleton systems to assist the physically less incapable people (PLIP) in rising up, sitting, ascending and descending staircases. Furthermore, key technologies of lower-limb exoskeleton systems are reviewed by taking state-of-the-art robot as examples. Keywords: List the Robotic exoskeleton systems, rehabilitation robotics, man-machine intelligent system

Abstract: The discrete-time adaptive sliding mode controller for spinning rockets in presence of parameter error is proposed. Considering the nonlinear characteristics for the system, input-output feedback linearization is utilized to transform the system model into two standard form subsystems. Then a discrete-time controller for guided rockets is designed based on discrete-time sliding mode control principle. In order to diminish the switch width of the discrete-time sliding mode system corresponding to parameter error, a dead-zone parameter adaptive law is designed. The stability of the uncertain closed-loop system is proved by Lyapunov theory, which make the controller have high robustness. Simulation result indicates that the proposed controller is robust with respect to large aerodynamic parametric uncertainty, and has excellent dynamic tracking performance.

Abstract: Finite-time Formation control of autonomous underwater vehicles (AUVs) is investigated. Considering the different communication ranges of multiple agents, we propose a hierarchical leader-follower finite-time consensus algorithm. The multiple agents are divided into three groups that are a global leader, local leaders and followers. Leaders form their positions according to their obtained information reliability. Simulations show the effectiveness of the proposed control scheme which can form predefined formation in finite time.