Optimal design and experimental verification of a spherical-wheel composite robot with automatic transformation system

This paper presents a design for a dual-mode prototype robot with the advantages of both a spherical robot and wheeled robot. A spherical robot has flexible movement capabilities, and the spherical shell can protect the mechanism and electronic devices. A wheeled mobile robot operates at high speed on a flat road. Its simple structure and control system has made it a popular choice in the field of robotics. Our objective was to develop a new concept robot capable of combining two different locomotion mechanisms to increase the locomotion stability and efficiency. The proposed mobile robot prototype was found to be capable and suitable in different situations. The exchange of modes between the spherical and the wheeled robot was realized by a structural change of the robot. The spherical-wheel mobile robot prototype is composed of a deformable spherical shell system, the propulsion system for the sphere and a wheeled mobile unit module. The exchange of locomotion modes was implemented by changing the geometric structure of spherical shell. The mechanical structure of the composite robot is presented in detail as well as the control system including hardware components and the software. The control system allowed for the automatic transformation of the composite robot between either of the locomotion modes. Based on analysis and simulation, the mechanism was optimized in its configuration and dimension to guarantee that robot had a compact structure and high efficiency. Finally, the experimental results of the transformation and motion processes provided dynamic motion parameters and verified the feasibility of the robot prototype

FUZZY BASED SELF-TRANSFORMING ROBOT

ABSTRACT Self-transforming robot is a robot which transforms its shape according to the hindrance occurring in the path where the robots are being moved. Such robots have been recognized as very attractive design in exhibiting the reliable transformation according to the situations. Military and defense application needs a robot should possess arbitrary movements like human. In some scenarios transformations are made by biological inspired control strategies using Central Pattern Generators (CPG). CPG is used in the locomotion control of snake robots, quadruped robots, to humanoid robots. This paper presents a Fuzzy system for the Self-transforming robot which possess alteration in its original shape to exhibit a human-like behavior while passing over the particular location. Quadrupedal locomotion on rough terrain and unpredictable environments is still a challenge, where the proposed system will provide the good adaptability in rough terrain. It allows the modulation of locomotion by simple control signal. The necessary conditions for the stable dynamic walking on irregular terrain in common are proposed. Extensive simulations are carried out to validate the performance of the proposed Fuzzy system using LABVIEW. Arbitrary parameters such as distance, angle and orientation of the obstacles are provided as input to the fuzzy system which gives the required speed modulation on the motoric module

A reconfigurable hybrid wheel-track mobile robot based on Watt II six-bar linkage

This paper presents the design and development of a novel reconfigurable hybrid wheel-track mobile robot (RHMBot). This new reconfigurable mobile robot is constructed based on a Watt II six-bar linkage; through structure reconfiguration, it can provide three locomotion modes as wheel mode, tracked mode, and climbing and roll-over mode. Mechanical design of the proposed RHMBot is introduced, and using mechanism decomposition kinematics of the reconfigurable frame is investigated. Locomotion of the robot is then interpreted associated with transformation of the reconfigurable frame. Further, deformation of the deformable track belt is characterized and static analysis of the reconfigurable frame is accomplished. Numerical simulation of the proposed reconfigurable frame is subsequently implemented, integrated with driving-torque associated parametric study, leading to optimization of the structure parameters. Consequently, prototype of the proposed RHMBot is designed and developed; exploiting which a series of field tests are conducted verifying feasibility and manoeuvrability of the proposed multi-locomotion mobile robot

변신 바퀴를 이용한 다중 지형 이동 로봇의 설계

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부, 2014. 2. 주종남.In this paper, the design, optimization, and performance evaluation of a new wheel-leg hybrid robot are reported. This robot utilizes a novel kind of transformable wheel for its locomotion to combine the advantages of both circular wheels and legged wheels. To minimize design complexity, this new transformable wheels transformation process is operated passively, which eliminates the need for additional actuators. A new triggering mechanism is also employed to increase the success rate of the transformation. To maximize the climbing ability in the legged-wheel mode, the design parameters of the transformable wheel and the robot are tuned based on behavioral analyses. The performance of our new development is evaluated in terms of stability, energy efficiency, and the maximum height of the obstacle the robot can climb over. By virtue of this transformable wheel, the system could climb over an obstacle 3.25 times as tall as its wheel radius, not compromising its driving ability at 2.4 body lengths per second with the specific resistance of 0.7 on flat surfaces.Abstract Contents List of Figures & Tables 1. Introduction 2. Design of the passive transformable wheel 2.1 Components design for coupled legs 2.2 Transformation mechanism 2.3 Triggering mechanism 2.4 Climbing scenario 3. Design optimization 3.1 Modeling of the passive transformable wheel 3.2 Maximizing the transformation ratio 3.3 Foot design for the higher success rate of the transformation 4. Design of the robotic platform 4.1 Features 4.2 Tuning design parameters for stable climbing 5. Results 5.1 Speed & specific resistance 5.2 Obstacle climbing 5.3 Discussion about mode switch 6. Conclusions References 국문초록Maste

Optimal design and experimental verification of a spherical-wheel composite robot with automatic transformation system

This paper presents a design for a dual-mode prototype robot with the advantages of both a spherical robot and wheeled robot. A spherical robot has flexible movement capabilities, and the spherical shell can protect the mechanism and electronic devices. A wheeled mobile robot operates at high speed on a flat road. Its simple structure and control system has made it a popular choice in the field of robotics. Our objective was to develop a new concept robot capable of combining two different locomotion mechanisms to increase the locomotion stability and efficiency. The proposed mobile robot prototype was found to be capable and suitable in different situations. The exchange of modes between the spherical and the wheeled robot was realized by a structural change of the robot. The spherical-wheel mobile robot prototype is composed of a deformable spherical shell system, the propulsion system for the sphere and a wheeled mobile unit module. The exchange of locomotion modes was implemented by changing the geometric structure of spherical shell. The mechanical structure of the composite robot is presented in detail as well as the control system including hardware components and the software. The control system allowed for the automatic transformation of the composite robot between either of the locomotion modes. Based on analysis and simulation, the mechanism was optimized in its configuration and dimension to guarantee that robot had a compact structure and high efficiency. Finally, the experimental results of the transformation and motion processes provided dynamic motion parameters and verified the feasibility of the robot prototype

Development of track-driven agriculture robot with terrain classification functionality / Khairul Azmi Mahadhir

Over the past years, many robots have been devised to facilitate agricultural activities (that are labor-intensive in nature) so that they can carry out tasks such as crop care or selective harvesting with minimum human supervision. It is commonly observed that rapid change in terrain conditions can jeopardize the performance and efficiency of a robot when performing agricultural activity. For instance, a terrain covered with gravel produces high vibration to robot when traversing on the surface. In this work, an agricultural robot is embedded with machine learning algorithm based on Support Vector Machine (SVM). The aim is to evaluate the effectiveness of the Support Vector Machine in recognizing different terrain conditions in an agriculture field. A test bed equipped with a tracked-driven robot and three types o f terrain i.e. sand, gravel and vegetation has been developed. A small and low power MEMS accelerometer is integrated into the robot for measuring the vertical acceleration. In this experiment, the vibration signals resulted from the interaction between the robot and the different type of terrain were collected. An extensive experimental study was conducted to evaluate the effectiveness of SVM. The results in terms of accuracy of two machine learning techniques based on terrain classification are analyzed and compared. The results show that the robot that is equipped with an SVM can recognize different terrain conditions effectively. Such capability enables the robot to traverse across changing terrain conditions without being trapped in the field. Hence, this research work contributes to develop a self-adaptive agricultural robot in coping with different terrain conditions with minimum human supervision