Glen Bright

Quad-Rotor Unmanned Aerial Vehicle Helicopter Modelling & Control

This paper presents the investigation of the modelling and control of a quad-rotor helicopter and forms part of research involving the development of an unmanned aerial vehicle (UAV) to be used in search and rescue applications. Quad-rotor helicopters consist of two pairs of counter rotating rotors situated at the ends of a cross, symmetric about the centre of gravity, which coincides with the origin of the reference system used. These rotors provide the predominant aerodynamic forces which act on the rotorcraft, and are modelled using momentum theory as well as blade element theory. From this, one can determine the expected payload capacity and lift performance of the rotorcraft. The Euler-Lagrange method has been used to derive the defining equations of motion of the six degree-of-freedom system. The Lagrangian was obtained by modelling the kinetic and potential energy of the system and the external forces obtained from the aerodynamic analysis. Based on this model, a control strategy was developed using linear PD controllers. A numerical simulation was then conducted using MATLAB® Simulink®. First, the derived model was simulated to investigate the behaviour of the rotorcraft, and then a second investigation was conducted to determine the effectiveness of the implemented control system. The results and findings of these investigations are then presented and discussed.

Development of an UAV for search & rescue applications

In the event of a disaster, there is an impending need for robotic assistance in order to conduct an effective search and rescue operation, due to their immediate permissible deployment. In this paper, the development of an unmanned aerial vehicle (UAV) intended for search and rescue applications is presented. The platform for the UAV is a quad-rotor type helicopter, simply referred to as a quadrotor. A plan for the mechatronic system integration was devised to combine the mechanical, electronic and software elements of the research. Once the system was modelled mathematically, a control strategy was implemented to achieve stability. This was investigated by creating a MATLAB® Simulink® numerical model, which was used to run simulations of the system.

A 7 DOF exoskeleton arm: Shoulder, elbow, wrist and hand mechanism for assistance to upper limb disabled individuals

This paper illustrates the mechanical structures spherical motion, kinematic matrices and achievable workspace of an exoskeleton upper limb device. The purpose of this paper is to assist individuals that have lost their upper limb motor functions by creating an exoskeleton device that does not require an external support; but still provides a large workspace. This allows for movement according to the Activities of Daily Living (ADL).

Automated pipe inspection robot

Automated inspection of the inner surface of a pipe can be achieved by a mobile robot. Pipe inspection is necessary to locate defects due to corrosion and wear while the pipe is transporting fluids. Pipe inspection devices are available for these tasks; they commonly use ultrasonic or magnetic flux variation to detect defects. Says that the magnitude of the costs involved in the development and implementation of these inspection techniques is such that it inhibits their more frequent and widespread use. Posits that the automated pipe inspection robot presented is a proposed cost‐effective alternative solution. The inspection device is a PC‐based design that uses mechatronic principles to ensure a purposeful interaction between the robot and its environment.

MODULAR RECONFIGURABLE MACHINE TOOLS: DESIGN, CONTROL AND EVALUATION

The reconfigurable manufacturing system (RMS) paradigm encapsulates methodologies that enable manufacturing systems to cope effectively with market and product changes. This research presents the design and evaluation of modular reconfigurable machine (MRM) tools as a novel machining solution within the scope of RMS. Mechanical and control designs are presented, outlining the development of this novel machining system. The property of hardware modularity displayed by MRMs enables an adjustment of system functionality and the synergistic redistribution of system resources between production streams, thus facilitating inter-process capacity scaling. Scalable production capacity and adjustable system functionality are the key objectives of reconfigurable manufacturing.

Bluetooth ubiquitous networks: seamlessly integrating humans and machines

The integration of humans and machines can be achieved using Bluetooth ubiquitous networks. Ideally, the interface between users and machines should be completely seamless and transparent. A user should not need to take any physical action to have a machine react to commands. A novel application area for Bluetooth communication technology is being developed in the Massey University Smart House project, in New Zealand. The creation of a Bluetooth ubiquitous network allows the house users to be tracked and monitored throughout the house. Their specific preferences or needs can automatically be taken care of by a control computer. This paper outlines and describes this seamless application.

A Portable Passive Physiotherapeutic Exoskeleton

The public healthcare system in South Africa is in need of urgent attention in no small part because there has been an escalation in the number of stroke victims which could be due to the increase in hypertension in this urbanizing society. There is a growing need for physiotherapists and occupational therapists in the country, which is further hindered by the division between urban and rural areas. A possible solution is a portable passive physiotherapeutic exoskeleton device. The exoskeleton device has been formulated to encapsulate methodologies that enable the anthropomorphic integration between a biological and mechatronic limb. A physiotherapeutic mechanism was designed to be portable and adjustable, without limiting the spherical motion and workspace of the human arm. The exoskeleton was designed to be portable in the sense that it could be transported geographically. It is a complete device allowing for motion in the shoulder, elbow, wrist and hand joints. The inverse kinematics was solved iteratively via the Damped Least Squares (DLS) method. The electronic and computer system allowed for professional personnel to either change an individual joint or a combination of joints angles via the kinematic models. A ramp PI controller was established to provide a smooth response to simulate the passive therapy motion.

Performance of the Improvements of the CAESAR Robot

Robots are able to enter concealed and unstable environments inaccessible to rescuers. Previous Urban Search And Rescue (USAR) robots have experienced problems with malfunction of communication systems, traction systems, control and telemetry. These problems were accessed and improved in developing a prototype robot called CAESAR, which is an acronym for Contractible Arms Elevating Search And Rescue. Problems encountered with previous USAR robots are discussed. The mechanical, sensory and communication systems that were used on CAESAR are briefly explained. Each system was separately tested by performed experiments. Results of field tests and the robot performance experienced during a disaster scenario that was created are discussed. The capabilities of CAESAR are explained in these tests to determine if some of the problems experienced previously are solved.

Modular Reconfigurable Machines Incorporating Modular Open Architecture Control

The reconfigurable manufacturing system (RMS) paradigm has been formulated to encapsulate methodologies that enable manufacturing systems to display a variability of system functionality and capacity in response to constantly changing production requirements. The formulation of a new class of production machinery, modular reconfigurable machines (MRMs), for RMS is presented. By virtue of their fully modular nature these machines are able to display a variability of machining functions and cutting degrees of freedom on a single platform. A corresponding modular open architecture control (OAC) system is presented. OAC overcomes the inflexibility of fixed proprietary automation, ensuring that MRMs provide the reconfigurability and extensibility necessary to meet the demands of modern manufacturing.

Feedback control of a self-balancing materials handling robot

The inverted pendulum problem is well-known as a good application for control engineering. An autonomous robot can use the principle of the inverted pendulum for its design. A two-wheeled robot has both static and dynamic design considerations when using the inverted pendulum principle. This paper investigates the effect of varying mass characteristics on the step response of a self-balancing materials handling robot for application in a reconfigurable manufacturing environment. This is done to determine whether an adaptive control system needs to be designed. The responses of four states for the varying mass characteristic are examined and findings are presented.