Automated soil hardness testing machine

This paper describes the design and performance of a mechatronic system for controlling a standard drop-hammer mechanism that is commonly used in performing outdoor soil or ground hardness tests. A low-cost microcontroller is used to control a hydraulic actuator to repeatedly lift and drop a standard free-falling weight that strikes a pipe (sampler) which is pushed deeper into the ground with each impact. The depth of the sampler pipe and position of the hydraulic cylinder are constantly monitored and the number of drops, soil penetration data and other variables are recorded in a database for future analysis. This device, known as the “EVH Trip Hammer”, allows the full automation and faster completion of what is typically a very labour-intensive and slow testing process that can involve human error and the risk of human injuries

Design Concepts for a Hybrid Swimming and Walking Vehicle

AbstractThis paper describes the design and proposed control methods for a 6-legged swimming and walking robot that can be used in a variety of different transportation and equipment control applications above ground, under water and above water. Known as the TURTLE (Tele–operated Unmanned Robot for Telemetry and Legged Exploration), a prototype of this mobile robot is currently being designed and developed for experimental testing in the near future. It will be powered by rechargeable electric batteries (to be recharged by solar panels) and all of its actuators will be electric motors, each controlled and monitored by onboard microcontrollers supervised by an onboard master computer. The TURTLE will be fitted with several high-resolution digital cameras, 3D laser and sonar scanners, an IMU (Inertial Management Unit), electronic compass, GPS (satellite navigation) module, underwater sonar transceiver hardware and two or more types of long-distance wireless communications hardware. The first prototype of the TURTLE will focus on basic tasks such as remote video surveillance, 3D terrain surface scanning (above ground and underwater), basic swimming styles, basic walking styles, climbing over large rocks and walking over very rough ground and steep terrain. This paper describes the main objectives, basic performance specifications, functions and mechanical design solutions that have been developed so far for this project. It covers details of the various different swimming modes and feasible solutions for achieving the main design objectives

Blind search inverse kinematics for controlling all types of serial-link robot arms

The main objective of 'Inverse Kinematics' (IK) is to find the joint variables of a serial-link manipulator to achieve a desired position and orientation relationship between the end-effector frame and a base (or reference) frame. This paper describes a general purpose Inverse Kinematics (IK) method for solving all the joint variables for any type of serial-link robotic manipulator using its Forward Kinematic (FK) solution

Dynamics and control of a VTOL quad-thrust aerial robot

Some possible useful applications for Vertical Take-Off & Landing (VTOL) Unmanned Aerial Vehicles (UAVs) include remote video surveillance by security personnel, scouting missions or munitions delivery for the military, filming sports events or movies from almost any angle and transporting or controlling equipment. This paper describes the design, control and performance of a low-cost VTOL quadrotor UAV, known as the QTAR (Quad Thrust Aerial Robot)

Game development tools for simulating robots and creating interactive learning experiences

There are several different ways to create and control virtual 3D (three-dimensional) models of robots, however, most of these methods can only be implemented or understood by experts with years of extensive experience in 3D graphics programming, 3D mathematics and a plethora of advanced skills in the areas of solid modelling and 3D animation. This paper presents a brief history and summary of the state-of-the-art in 3D game development tools and technologies which can be used to develop realistic looking graphics for developing user interfaces and robot control programming tools. It also presents a simple and easy-to-learn kinematic modelling and 3D simulation process using a 4 degree of freedom (4-dof) articulated robot leg for an amphibious walking and swimming robot that is currently being designed by the authors. This 4-dof robot leg will be used as an example or case study to demonstrate an effective method for motion control, animation and simulation. Also described are popular software tools and essential skills needed to create a simple 3D simulation program. The source code of the 3D simulation software for the 4-dof robot leg is listed and described to help readers apply such methods to other robot designs, devices and complex machinery

Design concepts for an energy-efficient amphibious unmanned underwater vehicle

This paper describes the conceptual design and operating principles of an oscillating-foil propulsion system for an unmanned underwater vehicle called TURTLE ('Tele-operated Unmanned Robot for Telemetry and Legged Exploration'), currently under development. This UUV ('Unmanned Underwater Vehicle) will be designed to be a 6-legged swimming and walking amphibious robot, fitted with foils (or flat fins) which can be manipulated with several degrees of freedom to produce highly efficient underwater propulsion forces. The legs will each have four degrees of freedom, of which the fourth is rotation of a foil that is fitted to the 'shin' to provide propulsion for swimming. By manipulating the movements and rotations of this foil, propulsion forces can be generated to implement a variety of swimming modes, each with its own advantages and disadvantages. The foils attached to the fins allow the main body to be controlled in all six degrees of freedom. It will also be an amphibious robot that will be able to transition between swimming mode and walking mode, for walking on an underwater surface or over dry land if power considerations permit. It must be powerful and strong enough to support itself and light payloads while walking over rough or undulating surfaces commonly found on a beach. The mechanical design will allow the absolute position and orientation of the body to be accurately controlled relative to the ground surface, whether above or below water, for the purpose of precision control of onboard tools and sensors. The space frame construction method keeps water drag low and allows large scale, strong, rigid structures and manipulator limbs (or links) to be built. Space frames also keep material cost, weight and actuator energy usage to very low levels. Such lightweight and energy efficient robots will be useful in many practical applications, such as oil and gas exploration, drilling, mining, construction, automated agriculture, military transport and space exploration

Force, compliance and position control for a space frame manipulator

This paper describes practical methods for achieving variable force, compliance and position control for a direct-drive, pneumatically powered 'variable geometry truss manipulator' (VGTM) built at University of Southern Queensland. The advantages of tetrahedral-tetrahedral VGTM structures are discussed including the kinematics for a fully operational prototype. The natural compliant behaviour of compressed gas is exploited using proportional valve control software. Experimental results are included for force and position control of a conventional pneumatic actuator

Simulating the kinematics and motions of robotic manipulators using 3D game development tools

There are several different ways to create and control virtual 3D (three-dimensional) models of robots, however, most of these methods can only be implemented or understood by experts with years of extensive experience in 3D graphics programming, 3D mathematics and a plethora of advanced skills in the areas of solid modelling and 3D animation. This paper presents a brief history and summary of the state-ofthe- art in 3D game development tools and technologies which can be used to develop realistic looking graphics for developing user interfaces and robot control programming tools. It also presents a simple and easy-to-learn kinematic modelling and 3D simulation process using a 4 degree of freedom (4-dof) articulated robot leg for an amphibious walking and swimming robot that is currently being designed by the authors. This 4-dof robot leg will be used as an example or case study to demonstrate an effective method for motion control, animation and simulation. Also described are popular software tools and essential skills needed to create a simple 3D simulation program. The source code of the 3D simulation software for the 4-dof robot leg is listed and described to help readers apply such methods to other robot designs, devices and complex machinery