Gait Analysis of Eight Legged Robot

For any legged mobile machine, gait is the methodical, logical and scientific lifting and placement of foot to follow desired path on the desired terrain. To run a walking machine on any terrain, selection and analysis of gait is must. To meet the locomotion characteristics of an eight-legged robot in this paper we describe gait analysis of eight legged spider like robot. The longitudinal gait stability margin of the robot changes with change in duty factor. We analyze the wave gait and equal phase gait for this legged robot and found that there is a jump in stability margin of full cycle equal phase gait to that of wave gait at duty factor 3/4, and stability margin of half cycle equal phase gait jumps to wave gait at duty factor 7/8. We try to verify our result through graphical and simulation analysis

Design Issues for Hexapod Walking Robots

Hexapod walking robots have attracted considerable attention for several decades. Many studies have been carried out in research centers, universities and industries. However, only in the recent past have efficient walking machines been conceived, designed and built with performances that can be suitable for practical applications. This paper gives an overview of the state of the art on hexapod walking robots by referring both to the early design solutions and the most recent achievements. Careful attention is given to the main design issues and constraints that influence the technical feasibility and operation performance. A design procedure is outlined in order to systematically design a hexapod walking robot. In particular, the proposed design procedure takes into account the main features, such as mechanical structure and leg configuration, actuating and driving systems, payload, motion conditions, and walking gait. A case study is described in order to show the effectiveness and feasibility of the proposed design procedure

Hexapod Robot Control

Tato práce popisuje obecnou problematiku kráčivých podvozků, zaměřuje se pak na hexapody. Popisuje jejich stavbu těla, analýzu končetin, popisuje také typy chůzí pro pohyb po rovném terénu a senzory pro měření vzdálenosti, které se používají pro orientaci robota v prostoru. Zaměřuje se na hexapoda typu PhantomX AX Hexapod Mark II.This thesis contains problematics of robots with peddal chassis and is focused on hexapods. It contains description of design of hexapod chassis, limb analysis, gaits for movement on flat terrain and sensors for ranged measurement. Thesis is focused on hexapod PhantomX AX Hexapod Mark II.

Design, Fabrication and Analysis of a Hexapod

The principle motivation behind the work is to present a fully fabricated Hexapod. Hexapod is a robot that has six legs for movement and thus quite a number of degree of freedom. . Numerous studies have been completed in examination focuses. Moving robots have pulled in significant consideration for a very long while now, on the other hand, just as early as this past year scientists have produced navigator robots, planned and assembled to fulfill the imagination, with exhibitions that can be suitable for handy applications. This paper gives an outline of the best in class on hexapods by alluding both to the early plan arrangements. Cautious consideration is given to the fundamental design issues and requirements that impact the specialized possibility and operation execution. A design flowchart was plotted with a specific end goal to efficiently plan a hexapod. Since the robot has numerous legs, the robot is effortlessly customized to move around in light of the fact that it can be designed to numerous sorts of gaits, for example, tripod, and wave, ripple and quadruped gaits etc. House of quality was used to compare and finalize among the probable design. A novel design has been created with CATIA. Mainly, the undertaken design outline takes into account the fundamental features, such as basic structure and mechanical configuration, electronics schematics, motion planning, payload, and walking gait. Kinematic as well as Dynamic Analysis had to be done using DH forward and Inverse matrix method. Simulation has been done in V-rep and excel simulator. Stress and displacement analysis was done for the feasibility of the model to sustain the weight of the body. Estimated physical parameters have been calculated. Control system design, gait implementation body manufacturing has been discussed. Bill of materials was generated and fabrication of Hexapod was completed. Future possibilities have been discussed

Mathematical Modelling and Control System Development of a Remote Controlled, IMU Stabilised Hexapod Robot

Walking robots are useful in search and rescue applications due to their ability to navigate uneven and complex terrain. A hexapod robot has been developed by the Robotics and Agents Research Lab at UCT, however multiple inadequacies have become evident. This work aims to produce a mathematical model of the hexapod and using this model, implement an effective control algorithm to achieve a smooth walking motion and overcome the original flaws. The mathematical model was integrated with the mechanical structure of the hexapod and controlled by a micro-controller. This micro-controller allows for a rapid start-up and low power consumption when compared to previous iterations of the hexapod. Using a path generation algorithm sets of foot positions and velocities are generated. Generating these points in real time allows for walking in any direction without any pre-defined foot positions. To enable attitude control of the hexapod body, an inertial measurement unit was added to the hexapod. By using a PID controller the IMU pitch and roll data was used to control a height offset of each foot of the hexapod, allowing for stabilisation of the hexapod body. An improved wireless remote control was developed to facilitate communication with a host computer. The remote system has a graphical user interface allowing for walking control and status information feedback, such as error information and current battery voltage. Walking tests have shown that the hexapod walks successfully with a smooth tripod gait using the path generation algorithm. Stabilisation tests have shown that the hexapod is capable of stabilising itself after a disturbance to its pitch and/or roll in ±2.5 seconds with a steady state error of ±0.001 radians. This proves that the hexapod robot can be controlled wirelessly while walking in any direction with a stabilised body. This is beneficial in search and rescue as the hexapod has a high degree of manoeuvrability to access areas too dangerous for rescuers to access. With cameras mounted on the stabilised body, it can be used to locate survivors in a disaster area and assist rescuers in recovering them with speed

Implementation of a Variable Duty Factor Controller on a Six-Legged Axi-Symmetric Walking Robot

Hexplorer is a six-legged walking robot developed at the University of Waterloo. The robot is controlled by a network of seven digital signal processors, six of which control three motors each, for a total of 18 motors. Brand new custom electronics were designed to house the digital signal processors and associated circuitry. A variable duty factor wave gait, developed by Yoneda et al. was simulated and implemented on the robot. Simulation required an in-depth kinematic analysis that was complicated by the mechanical design of parallel mechanism comprising the legs. These complications were handled in both simulation and implementation. However, due to mechanical issues Hexplorer walked for only one or two steps at a time

Climbing and Walking Robots

Nowadays robotics is one of the most dynamic fields of scientific researches. The shift of robotics researches from manufacturing to services applications is clear. During the last decades interest in studying climbing and walking robots has been increased. This increasing interest has been in many areas that most important ones of them are: mechanics, electronics, medical engineering, cybernetics, controls, and computers. Today’s climbing and walking robots are a combination of manipulative, perceptive, communicative, and cognitive abilities and they are capable of performing many tasks in industrial and non- industrial environments. Surveillance, planetary exploration, emergence rescue operations, reconnaissance, petrochemical applications, construction, entertainment, personal services, intervention in severe environments, transportation, medical and etc are some applications from a very diverse application fields of climbing and walking robots. By great progress in this area of robotics it is anticipated that next generation climbing and walking robots will enhance lives and will change the way the human works, thinks and makes decisions. This book presents the state of the art achievments, recent developments, applications and future challenges of climbing and walking robots. These are presented in 24 chapters by authors throughtot the world The book serves as a reference especially for the researchers who are interested in mobile robots. It also is useful for industrial engineers and graduate students in advanced study