Driverless Vehicles

There are many different types of driverless vehicles. These include vehicles where the

driver is remote and those controlled completely by computer with no human

intervention.

Smart Cars: The solution for dumb drivers

You can’t drive a Google car off a cliff. Other than that, they’re fantastic

“This is the direction the world is going,” says Barry Kirk, an Ontario engineer and director

of the Canadian Automated Vehicles Centre Of Excellence (CAVCOE). “It’s inevitable.”

The rise of the autonomous vehicle (AV) has taken place with surprising swiftness. Virtually every

major car manufacturer has developed a self-driving car, and Google has clocked close to one million

kilometres on its fleet of AVs in four U.S. states. Although state laws require a human driver behind

the wheel as a backup, Google cars have racked up a near-perfect safety record. The only crash

occurred when one of the cars was being operated by a human driver.

Surveys have shown that the majority of drivers distrust robot car technology, but analysts and

engineers say autonomous vehicles are inherently safer.“Computers don’t get distracted, and they

have no emotions,” says Martin Pietrucha, director of the Larson Transportation Institute at Penn

State University. “They are far more reliable than a human being.”

The development of autonomous cars is taking place on multiple fronts. A number of major

universities are running research programs, and several major manufacturers, including Volvo,

Nissan, GM and BMW, have announced plans to market autonomous vehicles by 2020. The

association of Electrical and Electronics Engineers (IEEE) has estimated that by 2040, up to 75 per

cent of all vehicles will be autonomous.

The elimination of the human driver is the next great transportation frontier. The road to the

autonomous car began with technologies like stability control and anti-lock brakes, which enhance

(and often correct) human performance. Features like adaptive cruise control, blind spot detection and

lane-keeping sensors have increased the “intelligence” of everyday cars, and paved the way to the full

automation.

Self-driving vehicles have been tested in a variety of environments. Suncor Energy, for example,

operates giant autonomous dump trucks in the Alberta oil sands. The cars in Google’s AV fleet have

navigated some of the most complex driving environments in North America, including San

Francisco’s Lombard Avenue, famous for its steep grade and switchback turns.

Next year, the British town of Milton Keynes will begin a public test of driverless, two-seat taxis. The

city expects to be running up to 100 of the autonomous taxis by 2017.

Analysts predict that the adoption of autonomous vehicles will follow a pattern similar to that of the

personal computer, with public acceptance steadily growing as the technology’s benefits are

demonstrated.Eliminating human drivers will have far-reaching social and economic implications.

Entire industries (like truck and cab driving) may be wiped out. AVs will also dramatically reduce

(and possibly eliminate) crashes – as safety experts can tell you, almost all accidents are caused by

human error. This will shift the landscape for industries like body repair and auto insurance.

There will also be a direct impact on the medical system. Treating car crash victims is a major

industry. A decline in crashes would sharply reduce the supply of human donor organs available for

transplant – the largest supply comes from drivers aged 18 to 30.

Autonomous cars will have a positive impact on congestion – they can operate at optimum speed and

spacing, maximizing traffic flow. They can also be used with networked control systems that optimize

traffic flow by commanding cars to take optimum routes, and letting each car know what other

vehicles are doing. This type of networked traffic system has already been developed for aviation –

the Next Generation Air Transportation System (NexGen) is starting to be phased in across the United

States.

Google has studied the impact of human drivers on road congestion by using what’s known as Agent-

Based Simulation – computers model traffic on a road system, and determine how flow is affected

when a percentage of drivers engage in behaviours like tailgating, speeding and rapid lane switching.

As the research has shown, these drivers have a significant impact on traffic flow.

Autonomous car

An autonomous car, also known as a driverless car, driver-free car, self-driving car or robot car,

is an autonomous vehicle capable of fulfilling the human transportation capabilities of a traditional

car. As an autonomous vehicle, it is capable of sensing its environment and navigating without human

input. Robotic cars exist mainly as prototypes and demonstration systems. Currently, the only self-

driving vehicles that are commercially available are open-air shuttles for pedestrian zones that operate

at 12.5 miles per hour (20.1 km/h).

Autonomous vehicles sense their surroundings with such techniques as radar, lidar, GPS, and

computer vision. Advanced control systems interpret sensory information to identify appropriate

navigation paths, as well as obstacles and relevant signage. Some autonomous vehicles update their

maps based on sensory input, allowing the vehicles to keep track of their position even when

conditions change or when they enter uncharted environments.

Some quasi-autonomous demonstration systems date back to the 1920s and the 1930s. Since the

1980s, when Mercedes-Benz and Bundeswehr University Munich built a driverless car through the

EUREKA Prometheus Project, significant advances have been made in both technology and

legislation relevant to autonomous cars. Numerous major companies and research organizations have

developed working prototype autonomous vehicles, including Mercedes-Benz, General Motors,

Continental Automotive Systems, Autoliv Inc., Bosch, Nissan, Toyota, Audi, Volvo, Vislab from

University of Parma, Oxford University and Google. In 2010, four electric autonomous vans

successfully drove 8000 miles from Italy to China. The vehicles were developed in a research project

backed by European Union funding, by Vislab of the University of Parma, Italy. In July 2013 Vislab

worldpremiered BRAiVE, a vehicle that moved autonomously on a mixed traffic route open to public

traffic. As of 2013, four U.S. states have passed laws permitting autonomous cars: Nevada, Florida,

California, and Michigan. In Europe, cities in Belgium, France, Italy and the UK are planning to

operate transport systems for driverless cars. Also in Europe, Germany, Netherlands and Spain have

allowed testing robotic cars in traffic. Finland is planning on passing a law before year 2015.

Definition

The term "autonomous" is not a generally accepted term in science when used to describe technical

artifacts. For example Wood et al. (2012), see reference below, writes "This Article generally uses the

term “autonomous,” instead of the term “automated.” We have chosen to use the term “autonomous”

because it is the term that is currently in more widespread use (and thus is more familiar to the general

public). However, the latter term is arguably more accurate. “Automated” connotes control or

operation by a machine, while “autonomous” connotes acting alone or independently. Most of the

vehicle concepts (that we are currently aware of) have a person in the driver’s seat, utilize a

communication connection to the Cloud or other vehicles, and do not independently select either

destinations or routes for reaching them. Thus, the term “automated” would more accurately describe

these vehicle concepts".

In the United States, the National Highway Traffic Safety Administration (NHTSA) has established

an official classification system

Level 0: The driver completely controls the vehicle at all times. Level 1: Individual vehicle controls are automated, such as electronic stability control or

automatic braking.

Level 2: At least two controls can be automated in unison, such as adaptive cruise control in

combination with lane keeping.

Level 3: The driver can fully cede control of all safety-critical functions in certain conditions.

The car senses when conditions require the driver to retake control and provides a

"sufficiently comfortable transition time" for the driver to do so.

Level 4: The vehicle performs all safety-critical functions for the entire trip, with the driver

not expected to control the vehicle at any time. As this vehicle would control all functions

from start to stop, including all parking functions, it could include unoccupied cars.

Potential advantages

An increase in the use of autonomous cars would make possible such benefits as:

Fewer traffic collisions, due to an autonomous system's increased reliability and faster

reaction time compared to human drivers.

Increased roadway capacity and reduced traffic congestion due to reduced need for safety

gaps and the ability to better manage traffic flow.

Relief of vehicle occupants from driving and navigation chores.

Higher speed limit for autonomous cars.

Removal of constraints on occupants' state – in an autonomous car, it would not matter if the

occupants were under age, over age, blind, distracted, intoxicated, or otherwise impaired.

Alleviation of parking scarcity, as cars could drop off passengers, park far away where space

is not scarce, and return as needed to pick up passengers.

Elimination of redundant passengers – the robotic car could drive unoccupied to wherever it

is required, such as to pick up passengers or to go in for maintenance. This would be

especially relevant to trucks, taxis and car-sharing services.

Reduction of space required for vehicle parking.

Reduction in the need for traffic police and vehicle insurance.

Reduction of physical road signage – autonomous cars could receive necessary

communication electronically (although physical signs may still be required for any human

drivers).

Smoother rides

Potential obstacles

In spite of the various benefits to increased vehicle automation, some foreseeable challenges persist:

Liability for damage

Resistance for individuals to forfeit control of their cars

Software reliability.

Cyber Security: A car's computer could potentially be compromised, as could a

communication system between cars.

Implementation of legal framework and establishment of government regulations for self-

driving cars

Drivers being inexperienced if situations arose requiring manual driving

Problems interacting with human-driven vehicles on the same road.

Loss of driving-related jobs.

Loss of privacy

Competition for the radio spectrum desired for the car's communication

Self driving cars could potentially be loaded with explosives and used as autonomous bombs.

Ethics: Ethical problems analogous to the trolley problem arise in situations where an

autonomous car's software is forced during an accident to choose between multiple courses of

action, all of which cause harm.

Semi-autonomous vehicles

Though not fully autonomous, there are features in which the vehicle will take control of itself for

either safety or convenience purposes. In 2014, features in which the vehicle takes control include:

cruise control

adaptive cruise control

stability control

precrash system

automatic parking

lane-keeping system

Vehicular communication systems

Individual vehicles may benefit from information obtained from other vehicles in the vicinity,

especially information relating to traffic congestion and safety hazards. Vehicular communication

systems use vehicles and roadside units as the communicating nodes in a peer-to-peer network,

providing each other with information. As a cooperative approach, vehicular communication systems

can allow all cooperating vehicles to be more effective. According to a 2010 study by the National

Highway Traffic Safety Administration, vehicular communication systems could help avoid up to 81

percent of all traffic accidents

In 2012, computer scientists at the University of Texas in Austin began developing smart intersections

designed for autonomous cars. The intersections will have no traffic lights and no stop signs, instead

using computer programs that will communicate directly with each car on the road

Proximity Sensors

A proximity sensor is a sensor able to detect the presence of nearby objects without any physical

contact.

A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation

(infrared, for instance), and looks for changes in the field or return signal. The object being sensed is

often referred to as the proximity sensor's target. Different proximity sensor targets demand different

sensors. For example, a capacitive or photoelectric sensor might be suitable for a plastic target; an

inductive proximity sensor always requires a metal target.

The maximum distance that this sensor can detect is defined "nominal range". Some sensors have

adjustments of the nominal range or means to report a graduated detection distance.

Proximity sensors can have a high reliability and long functional life because of the absence of

mechanical parts and lack of physical contact between sensor and the sensed object.

Types of sensors

Capacitive

Capacitive displacement sensor

Doppler effect (sensor based on effect)

Eddy-current

Inductive

Laser rangefinder

Magnetic, including Magnetic proximity fuse

Passive optical (such as charge-coupled devices)

Passive thermal infrared

Photocell (reflective)

Radar

Reflection of ionising radiation

Sonar (typically active or passive)

Ultrasonic sensor (sonar which runs in air)

Other Transport

Ground proximity warning system

A ground proximity warning system (GPWS) is a system designed to alert pilots if their aircraft is

in immediate danger of flying into the ground or an obstacle. The United States Federal Aviation

Administration (FAA) defines GPWS as a type of terrain awareness warning system (TAWS). More

advanced systems, introduced in 1996, are known as enhanced ground proximity warning systems

(EGPWS), although sometimes called terrain awareness warning systems.

Commercial aircraft

The FAA specifications have detailed requirements for when certain warnings should sound in the

cockpit.

The system monitors an aircraft's height above ground as determined by a radio altimeter. A computer

then keeps track of these readings, calculates trends, and will warn the captain with visual and audio

messages if the aircraft is in certain defined flying configurations ("modes").

The modes are:

1. Excessive descent rate ("SINK RATE" "PULL UP")

2. Excessive terrain closure rate ("TERRAIN" "PULL UP")

3. Altitude loss after take off or with a high power setting ("DON'T SINK")

4. Unsafe terrain clearance ("TOO LOW – TERRAIN" "TOO LOW – GEAR" "TOO LOW –

FLAPS")

5. Excessive deviation below glideslope ("GLIDESLOPE")

6. Excessively steep bank angle ("BANK ANGLE")

7. Windshear protection ("WINDSHEAR")

The traditional GPWS does have a blind spot. Since it can only gather data from directly below the

aircraft, it must predict future terrain features. If there is a dramatic change in terrain, such as a steep

slope, GPWS will not detect the aircraft closure rate until it is too late for evasive action.

In the late 1990s improvements were made and the system was renamed "Enhanced Ground

Proximity Warning System" (EGPWS/TAWS). The system was now combined with a worldwide

digital terrain database and relies on Global Positioning System (GPS) technology. On-board

computers compared its current location with a database of the Earth's terrain. The Terrain Display

now gave pilots a visual orientation to high and low points nearby the aircraft.

EGPWS software improvements were focused on solving two common problems; no warning at all,

and late or improper response.

No warning

The primary cause of CFIT occurrences with no GPWS warning is landing short. When the landing

gear is down and landing flaps are deployed, the GPWS expects the airplane to land and therefore,

issues no warning. EGPWS introduces the Terrain Clearance Floor (TCF) function, which provides

GPWS protection even in the landing configuration.

Late warning or improper response

The occurrence of a GPWS alert typically happens at a time of high workload and nearly always

surprises the flight crew. Almost certainly, the aircraft is not where the pilot thinks it should be, and

the response to a GPWS warning can be late in these circumstances. Warning time can also be short if

the aircraft is flying into steep terrain since the downward looking radio altimeter is the primary

sensor used for the warning calculation. The EGPWS improves terrain awareness and warning times

by introducing the Terrain Display and the Terrain Data Base Look Ahead protection.

Fly By Wire

Fly-by-wire (FBW) is a system that replaces the conventional manual flight controls of an aircraft

with an electronic interface. The movements of flight controls are converted to electronic signals

transmitted by wires (hence the fly-by-wire term), and flight control computers determine how to

move the actuators at each control surface to provide the ordered response. The fly-by-wire system

also allows automatic signals sent by the aircraft's computers to perform functions without the pilot's

input, as in systems that automatically help stabilize the aircraft

Fly-by wire systems are quite complex, but their operation can be explained in simple terms. When a

pilot moves the control column (or sidestick), a signal is sent to a computer (analogous to moving a

game controller) the signal is sent through multiple wires (channels) to ensure that the signal reaches

the computer. A 'Triplex' is when there are three channels being used. In an Analog system, the

computer receives the signals, performs a calculation (adds the signal voltages and divides by the

number of signals received to find the mean average voltage) and adds another channel. These four

'Quadruplex' signals are then sent to the control surface actuator, and the surface begins to move.

Potentiometers in the actuator send a signal back to the computer (usually a negative voltage)

reporting the position of the actuator. When the actuator reaches the desired position, the two signals

(incoming and outgoing) cancel each other out and the actuator stops moving (completing a feedback

loop). In a Digital Fly By Wire Flight Control System complex software interprets digital signals from

the pilots control input sensors and performs calculations based on the Flight Control Laws

programmed into the Flight Control Computers and input from the Air Data Inertial Reference Units

and other sensors. The computer then commands the flight control surfaces to adopt a configuration

that will achieve the desired flight path.

Automatic stability systems

Fly-by-wire control systems allow aircraft computers to perform tasks without pilot input. Automatic

stability systems operate in this way. Gyroscopes fitted with sensors are mounted in an aircraft to

sense movement changes in the pitch, roll and yaw axes. Any movement (from straight and level

flight for example) results in signals to the computer, which automatically moves control actuators to

stabilize the aircraft.

Safety and redundancy

Aircraft systems may be quadruplexed (four independent channels) to prevent loss of signals in the

case of failure of one or even two channels. High performance aircraft that have Fly-by-wire controls

(also called CCVs or Control-Configured Vehicles) may be deliberately designed to have low or even

negative stability in some flight regimes, the rapid-reacting CCV controls compensating for the lack

of natural stability.

Pre-flight safety checks of a fly-by-wire system are often performed using Built-In Test Equipment

(BITE). On programming the system, either by the pilot or groundcrew, a number of control

movement steps are automatically performed. Any failure will be indicated to the crews.

Some aircraft, the Panavia Tornado for example, retain a very basic hydro-mechanical backup system

for limited flight control capability on losing electrical power, in the case of the Tornado this allows

rudimentary control of the stabilators only for pitch and roll axis movements.

Weight saving

A FBW aircraft can be lighter than a similar design with conventional controls. This is partly due to

the lower overall weight of the system components, and partly because the natural stability of the

aircraft can be relaxed, slightly for a transport aircraft and more for a maneuverable fighter, which

means that the stability surfaces that are part of the aircraft structure can therefore be made smaller.

These include the vertical and horizontal stabilizers (fin and tailplane) that are (normally) at the rear

of the fuselage. If these structures can be reduced in size, airframe weight is reduced. The advantages

of FBW controls were first exploited by the military and then in the commercial airline market. The

Airbus series of airliners used full-authority FBW controls beginning with their A320 series, see A320

flight control (though some limited FBW functions existed on A310. Boeing followed with their 777

and later designs.

Electronic fly-by-wire systems can respond flexibly to changing aerodynamic conditions, by tailoring

flight control surface movements so that aircraft response to control inputs is appropriate to flight

conditions. Electronic systems require less maintenance, whereas mechanical and hydraulic systems

require lubrication, tension adjustments, leak checks, fluid changes, etc. Placing circuitry between

pilot and aircraft can enhance safety. For example, the control system can try to prevent a stall, or it

can stop the pilot from over stressing the airframe[

The main concern with fly-by-wire systems is reliability. While traditional mechanical or hydraulic

control systems usually fail gradually, the loss of all flight control computers could immediately

render the aircraft uncontrollable. For this reason, most fly-by-wire systems incorporate either

redundant computers (triplex, quadruplex etc.), some kind of mechanical or hydraulic backup or a

combination of both. A "mixed" control system such as the latter is not desirable and modern FBW

aircraft normally avoid it by having more independent FBW channels, thereby reducing the possibility

of overall failure to minuscule levels that are acceptable to the independent regulatory and safety

authority responsible for aircraft design, testing and certification before operational service

Digital systems

A digital fly-by-wire flight control system is similar to its analog counterpart. However, the signal

processing is done by digital computers and the pilot literally can "fly-via-computer". This also

increases the flexibility of the flight control system, since the digital computers can receive input from

any aircraft sensor (such as the altimeters and the pitot tubes). This also increases the electronic

stability, because the system is less dependent on the values of critical electrical components in an

analog controller

The computers sense position and force inputs from pilot controls and aircraft sensors. They solve

differential equations to determine the appropriate command signals that move the flight controls to

execute the intentions of the pilot.

The programming of the digital computers enable flight envelope protection. In this aircraft designers

precisely tailor an aircraft's handling characteristics, to stay within the overall limits of what is

possible given the aerodynamics and structure of the aircraft. For example, the computer in flight

envelope protection mode can try to prevent the aircraft from being handled dangerously by

preventing pilots from exceeding preset limits on the aircraft's flight-control envelope, such as those

that prevent stalls and spins, and which limit airspeeds and g forces on the airplane. Software can also

be included that stabilize the flight-control inputs to avoid pilot-induced oscillations.

Since the flight-control computers continuously "fly" the aircraft, pilot's workloads can be reduced.

Also, in military and naval applications, it is now possible to fly military aircraft that have relaxed

stability. The primary benefit for such aircraft is more maneuverability during combat and training

flights, and the so-called "carefree handling" because stalling, spinning and other undesirable

performances are prevented automatically by the computers.

Digital flight control systems enable inherently unstable combat aircraft, such as the F-117 Nighthawk

and the B-2 Spirit flying wing to fly in usable and safe manners.

Redundancy

If one of the flight-control computers crashes, or is damaged in combat, or suffers from "insanity"

caused by electromagnetic pulses, the others overrule the faulty one (or even two of them), they

continue flying the aircraft safely, and they can either turn off or re-boot the faulty computers. Any

flight-control computer whose results disagree with the others is ruled to be faulty, and it is either

ignored or re-booted. (In other words, it is voted-out of control by the others

In addition, most of the early digital fly-by-wire aircraft also had an analog electrical, a mechanical, or

a hydraulic back-up flight control system. The Space Shuttle has, in addition to its redundant set of

four digital computers running its primary flight-control software, a fifth back-up computer running a

separately developed, reduced-function, software flight-control system – one that can be commanded

to take over in the event that a fault ever affects all of the computers in the other four. This back-up

system serves to reduce the risk of total flight-control-system failure ever happening because of a

general-purpose flight software fault that has escaped notice in the other four computers.

For airliners, flight-control redundancy improves their safety, but fly-by-wire control systems also

improve economy in flight because they are lighter, and they eliminate the need for many mechanical,

and heavy, flight-control mechanisms. Furthermore, most modern airliners have computerized

systems that control their jet engine throttles, air inlets, fuel storage and distribution system, in such a

way to minimize their consumption of jet fuel. Thus, digital control systems do their best to reduce the

cost of flights.

Engine digital control

The advent of FADEC (Full Authority Digital Engine Control) engines permits operation of the flight

control systems and autothrottles for the engines to be fully integrated. On modern military aircraft

other systems such as autostabilization, navigation, radar and weapons system are all integrated with

the flight control systems. FADEC allows maximum performance to be extracted from the aircraft

without fear of engine misoperation, aircraft damage or high pilot workloads.

In the civil field, the integration increases flight safety and economy. The Airbus A320 and its fly-by-

wire brethren are protected from dangerous situations such as low-speed stall or overstressing by

flight envelope protection. As a result, in such conditions, the flight control systems commands the

engines to increase thrust without pilot intervention. In economy cruise modes, the flight control

systems adjust the throttles and fuel tank selections more precisely than all but the most skillful pilots.

FADEC reduces rudder drag needed to compensate for sideways flight from unbalanced engine thrust.

On the A330/A340 family, fuel is transferred between the main (wing and center fuselage) tanks and a

fuel tank in the horizontal stabilizer, to optimize the aircraft's center of gravity during cruise flight.

The fuel management controls keep the aircraft's center of gravity accurately trimmed with fuel

weight, rather than drag-inducing aerodynamic trims in the elevators.

Further developments

Fly-by-optics

Fly-by-optics is sometimes used instead of fly-by-wire because it can transfer data at higher speeds,

and it is immune to electromagnetic interference. In most cases, the cables are just changed from

electrical to optical fiber cables. Sometimes it is referred to as "fly-by-light" due to its use of fiber

optics. The data generated by the software and interpreted by the controller remain the same.

Power-by-wire

Having eliminated the mechanical transmission circuits in fly-by-wire flight control systems, the next

step is to eliminate the bulky and heavy hydraulic circuits. The hydraulic circuit is replaced by an

electrical power circuit. The power circuits power electrical or self-contained electrohydraulic

actuators that are controlled by the digital flight control computers. All benefits of digital fly-by-wire

are retained.

The biggest benefits are weight savings, the possibility of redundant power circuits and tighter

integration between the aircraft flight control systems and its avionics systems. The absence of

hydraulics greatly reduces maintenance costs. This system is used in the Lockheed Martin F-35

Lightning II and in Airbus A380 backup flight controls. The Boeing 787 will also incorporate some

electrically operated flight controls (spoilers and horizontal stabilizer), which will remain operational

with either a total hydraulics failure and/or flight control computer failure.

Fly-by-wireless

Wiring adds a considerable amount of weight to an aircraft; therefore, researchers are exploring

implementing fly-by-wireless solutions. Fly-by-wireless systems are very similar to fly-by-wire

systems, however, instead of using a wired protocol for the physical layer a wireless protocol is

employed.

In addition to reducing weight, implementing a wireless solution has the potential to reduce costs

throughout an aircraft's life cycle. For example, many key failure points associated with wire and

connectors will be eliminated thus hours spent troubleshooting wires and connectors will be reduced.

Furthermore, engineering costs could potentially decrease because less time would be spent on

designing wiring installations, late changes in an aircraft's design would be easier to manage, etc

Intelligent Flight Control System

A newer flight control system, called Intelligent Flight Control System (IFCS), is an extension of

modern digital fly-by-wire flight control systems. The aim is to intelligently compensate for aircraft

damage and failure during flight, such as automatically using engine thrust and other avionics to

compensate for severe failures such as loss of hydraulics, loss of rudder, loss of ailerons, loss of an

engine, etc. Several demonstrations were made on a flight simulator where a Cessna-trained small-

aircraft pilot successfully landed a heavily damaged full-size concept jet, without prior experience

with large-body jet aircraft. This development is being spearheaded by NASA Dryden Flight

Research Center. It is reported that enhancements are mostly software upgrades to existing fully

computerized digital fly-by-wire flight control system

An autopilot is a system used to control the trajectory of a vehicle without constant 'hands-on' control

by a human operator being required. Autopilots do not replace a human operator, but assist them in

controlling the vehicle, allowing them to focus on broader aspects of operation, such as monitoring

the trajectory, weather and systems. Autopilots are used in aircraft, boats (known as self-steering

gear), spacecraft, missiles, and others. Autopilots have evolved significantly over time, from early

autopilots that merely held an attitude to modern autopilots capable of performing automated landings

under the supervision of a pilot.The autopilot system on airplanes is sometimes colloquially referred

to as "George"

First autopilots

In the early days of aviation, aircraft required the continuous attention of a pilot in order to fly safely.

As aircraft range increased allowing flights of many hours, the constant attention led to serious

fatigue. An autopilot is designed to perform some of the tasks of the pilot.

The first aircraft autopilot was developed by Sperry Corporation in 1912. The autopilot connected a

gyroscopic heading indicator and attitude indicator to hydraulically operated elevators and rudder

(ailerons were not connected as wing dihedral was counted upon to produce the necessary roll

stability.) It permitted the aircraft to fly straight and level on a compass course without a pilot's

attention, greatly reducing the pilot's workload.

Lawrence Sperry (the son of famous inventor Elmer Sperry) demonstrated it in 1914 at an aviation

safety contest held in Paris. At the contest, Sperry demonstrated the credibility of the invention by

flying the aircraft with his hands away from the controls and visible to onlookers of the contest. Elmer

Sperry Jr., the son of Lawrence Sperry, and Capt Shiras continued work after the war on the same

auto-pilot, and in 1930 they tested a more compact and reliable auto-pilot which kept a US

Army Air Corps aircraft on a true heading and altitude for three hours

In 1930, the Royal Aircraft Establishment in England developed an autopilot called a pilots'

assister that used a pneumatically-spun gyroscope to move the flight controls.

Further development of the autopilot was performed, such as improved control algorithms

and hydraulic servomechanisms. Also, inclusion of additional instrumentation such as the

radio-navigation aids made it possible to fly during night and in bad weather. In 1947 a US

Air Force C-54 made a transatlantic flight, including takeoff and landing, completely under

the control of an autopilot.

In the early 1920s, the Standard Oil tanker J.A. Moffet became the first ship to use an

autopilot.

Modern autopilots

Not all of the passenger aircraft flying today have an autopilot system. Older and smaller general

aviation aircraft especially are still hand-flown, and even small airliners with fewer than twenty seats

may also be without an autopilot as they are used on short-duration flights with two pilots. The

installation of autopilots in aircraft with more than twenty seats is generally made mandatory by

international aviation regulations. There are three levels of control in autopilots for smaller aircraft. A

single-axis autopilot controls an aircraft in the roll axis only; such autopilots are also known

colloquially as "wing levellers," reflecting their limitations. A two-axis autopilot controls an aircraft

in the pitch axis as well as roll, and may be little more than a "wing leveller" with limited pitch

oscillation-correcting ability; or it may receive inputs from on-board radio navigation systems to

provide true automatic flight guidance once the aircraft has taken off until shortly before landing; or

its capabilities may lie somewhere between these two extremes. A three-axis autopilot adds control in

the yaw axis and is not required in many small aircraft.

Autopilots in modern complex aircraft are three-axis and generally divide a flight into taxi, takeoff,

climb, cruise (level flight), descent, approach, and landing phases. Autopilots exist that automate all

of these flight phases except taxi and takeoff. An autopilot-controlled landing on a runway and

controlling the aircraft on rollout (i.e. keeping it on the centre of the runway) is known as a CAT IIIb

landing or Autoland, available on many major airports' runways today, especially at airports subject to

adverse weather phenomena such as fog. Landing, rollout, and taxi control to the aircraft parking

position is known as CAT IIIc. This is not used to date, but may be used in the future. An autopilot is

often an integral component of a Flight Management System.

Modern autopilots use computer software to control the aircraft. The software reads the aircraft's

current position, and then controls a Flight Control System to guide the aircraft. In such a system,

besides classic flight controls, many autopilots incorporate thrust control capabilities that can control

throttles to optimize the airspeed, and move fuel to different tanks to balance the aircraft in an optimal

attitude in the air. Although autopilots handle new or dangerous situations inflexibly, they generally

fly an aircraft with lower fuel consumption than a human pilot.

The autopilot in a modern large aircraft typically reads its position and the aircraft's attitude from an

inertial guidance system. Inertial guidance systems accumulate errors over time. They will incorporate

error reduction systems such as the carousel system that rotates once a minute so that any errors are

dissipated in different directions and have an overall nulling effect. Error in gyroscopes is known as

drift. This is due to physical properties within the system, be it mechanical or laser guided, that

corrupt positional data. The disagreements between the two are resolved with digital signal

processing, most often a six-dimensional Kalman filter. The six dimensions are usually roll, pitch,

yaw, altitude, latitude, and longitude. Aircraft may fly routes that have a required performance factor,

therefore the amount of error or actual performance factor must be monitored in order to fly those particular routes. The longer the flight, the more error accumulates within the system. Radio aids such

as DME, DME updates, and GPS may be used to correct the aircraft position.

Computer system details

The hardware of an autopilot varies from implementation to implementation, but is generally designed

with redundancy and reliability as foremost considerations. For example, the Rockwell Collins

AFDS-770 Autopilot Flight Director System used on the Boeing 777 uses triplicated FCP-2002

microprocessors which have been formally verified and are fabricated in a radiation resistant process

Software and hardware in an autopilot is tightly controlled, and extensive test procedures are put in

place.

Some autopilots also use design diversity. In this safety feature, critical software processes will not

only run on separate computers and possibly even using different architectures, but each computer

will run software created by different engineering teams, often being programmed in different

programming languages. It is generally considered unlikely that different engineering teams will make

the same mistakes. As the software becomes more expensive and complex, design diversity is

becoming less common because fewer engineering companies can afford it. The flight control

computers on the Space Shuttle used this design: there were five computers, four of which

redundantly ran identical software, and a fifth backup running software that was developed

independently. The software on the fifth system provided only the basic functions needed to fly the

Shuttle, further reducing any possible commonality with the software running on the four primary

systems.

Stability augmentation systems

A stability augmentation system (SAS) is another type of automatic flight control system; however,

instead of maintaining the aircraft on a predetermined attitude or flight path, the SAS will actuate the

aircraft flight controls to dampen out aircraft buffeting regardless of the attitude or flight path. SAS

systems can automatically stabilize the aircraft in one or more axes. The most common type of SAS is

the yaw damper which is used to eliminate the Dutch roll tendency of swept-wing aircraft. Some yaw

dampers are integral to the autopilot system while others are stand-alone systems.

Yaw dampers usually consist of a yaw rate sensor (either a gyroscope or angular accelerometer), a

computer/amplifier and a servo actuator. The yaw damper uses yaw rate sensor to sense when the

aircraft begins a Dutch Roll. A computer processes the signals from the yaw rate sensor to determine

the amount of rudder movement that is required to dampen out the Dutch roll. The computer then

commands the servo actuator to move the rudder that amount. The Dutch roll is dampened out and the

aircraft becomes stable about the yaw axis. Because Dutch roll is an instability that is inherent to all

swept-wing aircraft, most swept-wing aircraft have some sort of yaw damper system installed.

There are two types of yaw dampers: series yaw dampers and parallel yaw dampers. The servo

actuator of a series yaw damper will actuate the rudder independently of the rudder pedals while the

servo actuator of a parallel yaw damper is clutched to the rudder control quadrant and will result in

pedal movement when the system commands the rudder to move.

Some aircraft have stability augmentation systems that will stabilize the aircraft in more than a single

axis. B-52s, for example, require both pitch and yaw SAS in order to provide a stable bombing

platform. Many helicopters have pitch, roll and yaw SAS systems. Pitch and roll SAS systems operate

much the same way as the yaw damper described above; however, instead of dampening out Dutch

roll, they will dampen pitch and roll oscillations or buffeting to improve the overall stability of the

aircraft.

Autopilot for ILS landings

Instrument-aided landings are defined in categories by the International Civil Aviation Organization,

or ICAO. These are dependent upon the required visibility level and the degree to which the landing

can be conducted automatically without input by the pilot.

CAT I - This category permits pilots to land with a decision height of 200 ft (61 m) and a forward

visibility or Runway Visual Range (RVR) of 550 m. Autopilots are not required. [8]

CAT II - This category permits pilots to land with a decision height between 200 ft and 100 ft (≈ 30

m) and a RVR of 300 m. Autopilots have a fail passive requirement.

CAT IIIa -This category permits pilots to land with a decision height as low as 50 ft (15 m) and a

RVR of 200 m. It needs a fail-passive autopilot. There must be only a 10−6 probability of landing

outside the prescribed area.

CAT IIIb - As IIIa but with the addition of automatic roll out after touchdown incorporated with the

pilot taking control some distance along the runway. This category permits pilots to land with a

decision height less than 50 feet or no decision height and a forward visibility of 250 ft (76 m,

compare this to aircraft size, some of which are now over 70 m long) or 300 ft (91 m) in the United

States. For a landing-without-decision aid, a fail-operational autopilot is needed. For this category

some form of runway guidance system is needed: at least fail-passive but it needs to be fail-

operational for landing without decision height or for RVR below 100 m.

CAT IIIc - As IIIb but without decision height or visibility minimums, also known as "zero-zero".

Fail-passive autopilot: in case of failure, the aircraft stays in a controllable position and the pilot can

take control of it to go around or finish landing. It is usually a dual-channel system.

Fail-operational autopilot: in case of a failure below alert height, the approach, flare and landing can

still be completed automatically. It is usually a triple-channel system or dual-dual system.

Drones?

What are Drones?

Unmanned aerial vehicles (UAVS), also known as drones, are aircraft either controlled by ‘pilots’

from the ground or increasingly, autonomously following a pre-programmed mission. (While there

are dozens of different types of drones, they basically fall into two categories: those that are used for

reconnaissance and surveillance purposes and those that are armed with missiles and bombs. The

use of drones has grown quickly in recent years because unlike manned aircraft they can stay aloft for

many hours (Zephyr a British drone under development has just broken the world record by flying for

over 82 hours nonstop); they are much cheaper than military aircraft and they are flown remotely so

there is no danger to the flight crew.

While the British and US Reaper and Predator drones are physically in Afghanistan and Iraq, control

is via satellite from Nellis and Creech USAF base outside Las Vegas, Nevada. Ground crews launch

drones from the conflict zone, then operation is handed over to controllers at video screens in

specially designed trailers in the Nevada desert. One person ‘flies’ the drone, another operates and

monitors the cameras and sensors, while a third person is in contact with the “customers”, ground

troops and commanders in the war zone. While armed drones were first used in the Balkans war, their

use has dramatically escalated in Afghanistan, Iraq and in the CIA’s undeclared war in Pakistan.

The US has two separate ‘squadron’ of armed drones – one run by the US Air Force and one run by

the CIA. Using drones, the USAF Air Force has increased the number of combat air patrols it can fly

by 600 percent over the past six years; indeed at any time there are at least 36 American armed UAVS

over Afghanistan and Iraq. It plans to increase this number to 50 by 2011. CIA Director Leon Panetta

has recently said that drones are “the only game in town.” The CIA have been using drones in

Pakistan and other countries to assassinate “terrorist leaders.” While this programme was initiated by

the Bush Administration, it has increased under Obama and there have been 41 known drone strikes in

Pakistan since Obama became President. Analysis by an American think tank The Brookings

Institution on drone attacks in Pakistan has shown that for every militant leader killed, 10 civilians

also have died.

Drones UK The UK has several different types of armed and surveillance drones in Iraq and Afghanistan and

others in the production or development stage. The UK began using armed drones in Afghanistan in

Oct 2007 after purchasing three Reapers from General Atomics in 2007 at a cost of £6m each. The

MoD confirmed in June 2008 that a British Reaper UAV had fired its weapons for the first time, but

refused to give any details. In March 2009, the Daily Telegraph reported that British drones had been

used ten times in armed strikes.

Watchkeeper As well as armed drones, the UK has several types of surveillance drones, most notably Watchkeeper,

a drone jointly produced by Israeli company Ebit and Thales UK. The UK is purchasing 54

Watchkeeper drones and ground stations at a cost of £860m. The first ten will be built in Israel and

then production will transfer to a specially built facility in Leicester. Testing is taking place at

Aberporth in Wales and Watchkeeper is due to enter service in 2010. There have recently been reports

that Watchkeeper may be armed in the future.

Serious Concern Thes UN’s Special Rapporteur on extrajudicial, summary or arbitrary executions, Philip Alston, has

said that the use of drones is not combat as much as ‘targeted killing’. He has repeatedly tried to get

the US to explain how they justifies the use of drones to target and kill individuals under international

law. The US has so far refused to do so. In a report to the UN he has said the US government (and by

implication the UK government) “should specify the bases for decisions to kill rather than capture

particular individuals …. and should make public the number of civilians killed as a result of drone

attacks, and the measures in place to prevent such casualties”.

A further question is the extent to which operators become trigger happy with remote controlled

armaments, situated as they are in complete safety, distant from the conflict zone. Keith Shurtleff, an

army chaplain and ethics instructor at Fort Jackson, South Carolina worries “that as war becomes

safer and easier, as soldiers are removed from the horrors of war and see the enemy not as humans but

as blips on a screen, there is very real danger of losing the deterrent that such horrors provide.”

Increased Surveillance Military drone manufacturers are looking for civilian uses for remote sensing drones to expand their

markets and this includes the use of drones for domestic surveillance. Drones will no doubt make

possible the dramatic expansion of the surveillance state. With the convergence of other technologies

it may even make possible machine recognition of faces, behaviours, and the monitoring of individual

conversations. The sky, so to speak, is the limit.

Robot Lawn Mowers

The Honda Miimo lawnmower keeps a lawn perfectly trimmed and then find its way back to the

charging dock when it’s done. All you have to do is run a thin wire around the area you want mowed

and the Miimo will do the rest. Several times a week, it will undock itself and proceed to clip

precisely 0.8 to 0.11 millimeters (about 1/10th “) off the top of grass. Instead of following the

traditional up and back pattern, it does its mowing in a random pattern. Honda says the small amount

of grass removed and the random cutting place less stress on grass, giving you a healthier lawn. It also

allows the mower to turn the clippings into compost, eliminating the need to clean up afterwards. No

more hauling grass clippings to a remote corner of the yard. Miimo has a 360 degree perimeter sensor

that also ensures it won’t run into the kids or family pet. If it runs into something unexpected, it will

automatically change course and head off in a new direction, and the low deck design makes it almost

impossible to actually be hurt by this thing.

Remote Tractors or robot 'swarms'

A Mr Bate has been driving the development of robotic technology along with partner Queensland

University of Technology (QUT) and the Australian Centre for Field Robotics (ACFR) and will

provide growers and advisers with an insight into robotics in grain production, including what’s ready

now and where development is heading. “What we’re looking at is technology that will flip modern

farming practices on their head. For years we thought that by going bigger - using bigger machinery

in our paddocks - we were being more efficient. But really, each time we went bigger we went

backwards, particularly regarding soil compaction,” Mr Bate said. “Robotics will be the way of the

future” He said a fleet of small autonomous vehicles (robots) he was involved in developing for

spraying, among other things, had the potential to spark as big a shift in agriculture as horse to tractor.

“We are looking at swarms of small, lightweight machines that work together in a co-operative team.

So instead of one large tractor you might have six small ones about the size of a ride on lawn mower.

Small means little or no soil compaction, so farmers can reclaim their paddocks.