Chapter 4treats the fundamentals of radio propagation path loss, also known as large-scale fading. A wide range of practical radio propagation models are presented, and the fundamental theories of reflection, scattering, and diffraction are presented with many examples. These propagation mechanisms give rise to level of coverage and interference experienced in any wireless network, and, in urban environments, it is shown how the radar cross-section and ray tracing models can give accurate prediction of large-scale path loss in a mobile communication system. Shadowing is also considered, and the log-normal distribution is found to describe the shadowing about the distance-dependent mean signal level. Statistical approaches to quantifying outage are provided.

Although the vast majority of mobile robotic systems involve a single robot operating alone in its environment, a growing number of researchers are considering the challenges and potential advantages of having a group of robots cooperate in order to complete some required task. For some specific robotic tasks, such as exploring an unknown planet [374], search and rescue [812], pushing objects [608], [513], [687], [821], or cleaning up toxic waste [609], it has been suggested that rather than send one very complex robot to perform the task it would more effective to send a number of smaller, simpler robots. Such a collection of robots is sometimes described as a swarm [81], a colony [255], or a collective [436], or the robots may be said to exhibit cooperative behavior [607].

Robots in fiction seem to be able to engage in complex planning tasks with little or no difficulty. For example, in the novel 2001: A Space Odyssey, HAL is capable of long-range plans and reasoning about the effects and consequences of his actions [167]. It is indeed fortunate that fictional autonomous systems can be presented without having to specify how such devices represent and reason about their environment. Unfortunately, real autonomous systems often make explicit internal representations and mechanisms for reasoning about them.

Called “the rock that burns” by Aristotle, coal was the first major industrial fuel, created about 300 million years ago as heat and pressure compressed pools of decaying plant matter. Burned to generate heat to boil water and make steam to move a piston in a Watt “fire engine” or a giant turbine in a modern power station, the industrialization of manufacturing, transportation, and electric power is examined from beginnings in the United Kingdom to today’s increased use of coal combustion in developing countries despite the limited thermal efficiency and harmful combustion by-products.

A transition simplifies or improves the efficiency of old ways, turning intellect into industry with increased capital – when both transpire, change becomes unstoppable. The transition to a more efficient combustion fuel changed the global economy when coal replaced wood (twice as efficient) and oil replaced coal (roughly twice as efficient again). The history of the Industrial Revolution is explained through the energy content of different fuels (wood, peat, coal) from the 1800s, early steam engines that produced power for manufacturing and propulsion, and the political, economic, and social consequences of industrialization (wealth, health, and globalization), culminating in Thomas Edison’s 1882, coal-fired, electricity-generating, power station in Lower Manhattan.

Anyone who has had to move about in the dark recognizes the importance of vision to human navigation. Tasks that are fraught with difficulty and danger in the dark become straightforward when the lights are on. Given that humans seem to navigate effortlessly with vision, it seems natural to consider vision as a sensor for mobile robots. Visual sensing has many desirable potential features, including that it is passive and has high resolution and a long range.

There is much to do to create a modern energy paradigm, one that is clean, sustainable, and economically viable, but the changes are coming as overall efficiencies improve and manufacturing costs decrease for today’s renewable technologies. In 2000, 0.6% of total global energy production was generated either by wind or solar, a 50% increase in a decade; by 2010, the amount had doubled.1 By 2013, Spain had achieved a global first as wind-generated power became its main source of energy (21% of total demand, enough to run 7 million homes2), while both Portugal and Denmark now regularly produce days powered 100% by wind.

Historically cloudy England scored a first, as solar became the largest source of grid energy during an especially sunny 2018 spring bank-holiday weekend,3 while in the midst of high winds from Storm Bella on Boxing Day in 2020, the UK was more than half powered by wind, a new record.