Locomotion Interfaces for Legged Robots

This chapter presents a comparative study of the topographical structure of three common biological robotic inspirations: human, canine, and feline feet. It is shown that the metrological roughness of each of the examined feet is customized for the specific locomotion demands of the species. The textural parameters manifest close correlation to the pressure distribution experienced in movement and gait. This correlation enhances the durability and structural integrity of the bio-analogue. It is also shown that the metrological function of the human (plantigrade) feet pads combine that of the back and the front feet pads of the digitigrade mammals examined. It is argued that integrating the targeted engineering of roughness within the design process of robotic feet can enhance the function of walking robots. Further, it offers elegant solutions to some of the current problems encountered in design of humanoids and other bio-inspired walking robots.

A Proposed Trajectory Planning Algorithm for Mobile Robot Navigation Based on A* Algorithm

This chapter proposes a new trajectory planning approach by improving A* algorithm, which is a widely-used, path-planning algorithm. This algorithm is a heuristic method used in maps such as the occupancy grid map. As the resolution increases in these maps, obstacles can be defined more precisely. However, the cell/grid size must be larger than the size of the mobile robot to prevent the robot from crashing into the borders of the working environment or obstacles. The second constraint of the algorithm is that it does not provide continuous headings. In this study, an avoidance area is calculated on the map for the mobile robot to avoid collisions. Then curve-fitting methods, general polynomial and b-spline, are applied to the path calculated by traditional A* algorithm to obtain smooth rotations and continuous headings by staying faithful to the original path calculated. Performance of the proposed trajectory planning method is compared to others for different target points on the grid map by using a software developed in Labview Environment.

Membrane Micro Electro-Mechanical Systems for Industrial Applications

The objective of this chapter is to provide the analytical-numerical tools for the simplified rewriting of the most important mathematical models of MEMS membrane devices for Mechatronics, exploiting advanced concepts and results in the theory of curves and surfaces. Moreover, when the solution in closed form could not be obtained (that is, it is impossible to obtain the membrane deflection analytically), some consolidated techniques will be described both to obtain conditions ensuring existence/uniqueness of the solution, and the most suitable approaches for obtaining numerical solutions in the absence of ghost solutions. Finally, some practical examples will illustrate the approaches presented.

Safe Development Environments for Radiation Tracing Robots

Robots can substitute for men in radioactively-contaminated areas. This is a suitable field to deploy robots for measurements, repair, or clearance, but development and test of such robots could be dangerous, because radiation sources need to be handled. To avoid these hazards in development or public demonstrations, safe alternatives to radiation samples have been sought using an already existing robot (EtaBot). One proposed solution is an optical substitution (“light follower”), the other one a fully-digital simulation of the contaminated area and the robot movement inside it using a hardware-in-the-loop simulator (HiL).

Mechatronic Design of Low-Cost Control Systems for Rehabilitation and Assisting Devices

In this chapter, authors focus on mechatronic solutions for low-cost control devices for the homecare of elderly and people with reduced mobility, having the goal of assisting people in daily-life activities. The development of such systems can be exploited in the form of a toolkit to be flexible and applied either to rehabilitation or assistive systems, in order to aid movements with controlled position, force/torque, and acceleration, possibly introducing reliability, repetitiveness, and low cost in the related sector. In particular, the development of a low-cost control system design allows the applicability of the solution to a broad range of devices for the home-care. The authors aim to develop low-cost technologies for the homecare of elderly and people with motor impairments trying to reduce significantly the overall costs to facilitate wider use of assisting and rehabilitation systems. In particular, a Sit-To-Stand (STS) assisting device is considered as a paradigmatic example to illustrate design considerations.

Design and Implementation of a Smart Mechatronic Elbow Brace

This project develops a design and implementation of a smart mechatronic brace used as a rehabilitation device for elbow injury patients training their bone ligaments and muscles, and recovering at home. The proposed brace is designed to be low cost and to fit large different users since it is able to be regulated and combined with reliable mechanical and electronic parts, and to correspond to high safety requirements. Electromyography (EMG) sensors are used above the skin to measure the biopotential signals from the muscles to detect the human motion intention, and then, to recognize the flexion/extension movement. Data of the human motion intention and direction are processed and converted into the pulse-width modulation signals (PWM) to run DC motors. A prototype for this brace is fabricated and tested with real human motion intentions and directions. The DC motors can follow well the human motions with the error of less than 70 over a moving angle of 1200.

Robust and Intelligent Control Techniques for Twin Rotor System

During recent decades, popularity of unmanned aerial vehicles has increased throughout academics, engineers, as well as students because of their wide range of application areas such as inspection, communication, and transportation. The twin rotor system represents the nonlinear and coupled dynamics of a helicopter to a certain extent. Therefore, it provides a good test bed for engineering students' education on dynamics of aerial vehicles and control of mechatronic systems. In this study, sliding mode and fuzzy logic controllers are designed to control hovering motion of this highly nonlinear system. A robust sliding mode controller is preferred since it is insensitive to external disturbances, and intelligent fuzzy logic control is preferred since it is applicable to nonlinear systems where exact model of the system is not needed. Designed controllers, which are robust and intelligent, are then applied to the twin rotor system in real time. Then, experimental results are presented and discussed in terms of control performances of the designed controllers in detail.

Dynamic Modelling and Control of an Underactuated Quasi-Omnidireccional Hexapod

This chapter presents the mechanical design, dynamic model, and walking control law of an insect-like, asymmetric hexapod robot. The proposed model is an original walking mechanism designed with three actuators to provide quasi-omnidirectionality. One of the motivational aims is to reduce the number of actuators preserving similar holonomy as compared to popular 18-servo redundant hexapods with three servos per leg. This work includes the Klann mechanism as limb, two-drive differential robot's control, one per lateral triplet of legs. The legs of a triplet are synchronized in speed with different rotary angles phase. In addition, the six limbs are synchronized with bidirectional yaw motion. The proposed mechanical design has one servo for limbs yawing, one for the right limbs triplet and one motor for the left triplet. Thus, quasi-omnidirectional mobility is achieved. Furthermore, a dynamic control law that governs the robot's mechanisms motion is deduced, with an Euler-Lagrange approach. Kinematic and dynamic results are validated through numerical simulations using a tripod gait.

Control of a Wing Type Flat-Plate for an Ornithopter Autonomous Robot With Differential Flatness

In this chapter, a two-degree-of-freedom controller that exploits the flat properties of a three degree-of-freedom wing type flat-plate for an Ornithopter Autonomous robot is proposed. A set of kinematical patterns inspired by nature is used to simulate the wing's movement around two wingtip trajectories; also, the effects of the aerodynamical forces as a function of the wind velocity and the wing's angle of attack are considered. In order to control the system, the effects of these forces are viewed as disturbs that affect the wing's dynamics. The proposed control scheme drives the device through the desired path by generating a set of desired inputs which are compensated by a feedback loop when the aerodynamical forces actuate upon the system.

Analyses on Engineering Mechanics of Robotic Arm for Sorting Multi-Materials

The study involves static analysis on the developed robotic arm. Increasing loads are applied to the robotic arm to determine the maximum load that it can hold. Firstly, the robotic arm model is created using CATIA. Then, it is analyzed using the generative structural analysis tool in the same software. Increasing loads are applied to the end of the robotic arm until significant deformation occurs. The same procedure is done for modified designs in the analysis software. The results considered include displacement and stress. Based on the results, the critical stress areas are near to the rotating joints of the robotic arm, the back of the gripper and the sharp edge of the second arm. Proposed modifications include increasing the servo motor shaft radius and edge filleting the affected area, increasing the thickness and reducing the length of the gripper base plate, and implementing a new design for the second arm.