Phil Birch

Microfabrication by use of a Spatial Light Modulator in the Ultraviolet: Experimental results

We report the development of a new microstereophotolithography technique for creation of three-dimensional microcomponents by use of a planar, layer-by-layer process of exposure, in which a spatial light modulator is used as a dynamic lithographic mask. The system operates in the UV to take advantage of the wide supply of commercially available photopolymers designed for conventional stereolithography. With this novel procedure it is possible to build components with feature sizes as small as a few micrometers. The experimental setup is briefly described, and the first microcomponent fabricated by this system is shown.

Motion control design for unmanned ground vehicle in dynamic environment using intelligent controller

Purpose The motion control of unmanned ground vehicles (UGV) is a challenge in the industry of automation. The purpose of this paper is to propose a fuzzy inference system (FIS) based on sensory information for solving the navigation challenge of UGV in cluttered and dynamic environments. Design/methodology/approach The representation of the dynamic environment is a key element for the operational field and for the testing of the robotic navigation system. If dynamic obstacles move randomly in the operation field, the navigation problem becomes more complicated due to the coordination of the elements for accurate navigation and collision-free path within the environmental representations. This paper considers the construction of the FIS, which consists of two controllers. The first controller uses three sensors based on the obstacles distances from the front, right and left. The second controller employs the angle difference between the heading of the vehicle and the targeted angle to obtain the optimal route based on the environment and reach the desired destination with minimal running power and delay. The proposed design shows an efficient navigation strategy that overcomes the current navigation challenges in dynamic environments. Findings Experimental analyses are conducted for three different scenarios to investigate the validation and effectiveness of the introduced controllers based on the FIS. The reported simulation results are obtained using MATLAB software package. The results show that the controllers of the FIS consistently perform the manoeuvring task and manage the route plan efficiently, even in a complex environment that is populated with dynamic obstacles. The paper demonstrates that the destination was reached optimally using the shortest free route. Research limitations/implications The paper represents efforts toward building a dynamic environment filled with dynamic obstacles that move at various speeds and directions. The methodology of designing the FIS is accomplished to guide the UGV to the desired destination while avoiding collisions with obstacles. However, the methodology is approached using two-dimensional analyses. Hence, the paper suggests several extensions and variations to develop a three-dimensional strategy for further improvement. Originality/value This paper presents the design of a FIS and its characterizations in dynamic environments, specifically for obstacles that move at different velocities. This facilitates an improved functionality of the operation of UGV.

Advanced MagLev Propulsion System and its Economic Impact

*† ‡ § ** Rocketry can be considered as the enabler of more or less all space technologies. Its ability to deliver satellites at reasonable costs has made us dependent on this delivery mechanism to fulfill our daily tasks, be it communications, satellite navigation, visual entertainment or weather forecasting. Scientifically, advances in rocketry have enabled us to view the ever-expanding universe. Its most significant impact however comes in the form of manned spaceflight vehicles such as the Space Shuttle, Soyuz and now Space Ship One. A significant development is greater commercialization of manned rocketry, helping provide widespread access to space. Most rocket designs use some form of chemical propellant as their dominant fuel source, primarily as combustion of these propellants provides ample power at limited costs. However, over the last decade as the price of chemical propellants continues to soar and their detrimental effect on our environment comes to light, there has been significant interest in developing an alternative propulsion mechanism to power a new generation of space vehicles. There is now, more than ever, the need for a greener technology, which is capable of providing a similar power output without compromising on safety and reliability. This paper proposes the use of magnetic levitation and propulsion within a vacuum chamber as that technology. It aims to prove that such a system, located strategically close to the equator, is capable of providing adequate thrust to future space vehicles, be it for space tourism or exploration. Although, inception and creation of such a system may seem radical and expensive, the long-term costs are relatively lower than current day systems.

ASIFT based recognition of fixed shape moving objects and tracking via modified particle filters

Object Recognition and Tracking are one of the key research areas in image processing and computer vision. This paper presents a novel technique which efficiently recognizes an object based on full boundary detection using affine scale invariant feature transform method (ASIFT). ASIFT is an improvement to SIFT algorithm as it provides invariance up to six parameters longitude and latitude wise. The six parameters are based on translation (2 parameters), rotation, camera axis orientation (2 parameters) and zoom. Key points commonly referred to as feature points are then obtained using the mentioned parameters which will recognize the object efficiently. Furthermore a region merging technique is used for object recognition and detection in the remote scene environment using ASIFT technique. A short pictorial comparison between SIFT and ASIFT will also be presented based on feature points calculation. After the recognition using ASIFT is performed, an algorithm will be presented for tracking of the recognized object using modified particle filter. The particle filter will use a proximal gradient (PG) approach for tracking of the recognized object in subsequent images. In case an object drastically varies its position w.r.t any of the six parameters mentioned above, ASIFT will again be called for object recognition.