Draft:Original research/Repellor vehicles

A repellor vehicle is a vehicle (with human driver or virtual operator) that steers away from obstacles so as to arrive at a destination safely. A military vehicle, on the contrary, may wish to move toward an obstacle so as to remain undetected by keeping that object between its ultimate destination and those at the destination that may want to detect it. Overall there are three main techniques of driver interaction:
 * 1) direct user interaction,
 * 2) physical controls, and/or
 * 3) virtual controls.

Attractors
“An attractor is an object which draws the user [or vehicle] towards itself ... such as a planet with a simulated [or real] gravity”. “[A] planet revolving around the [S]un” is an autonomous attractor. “Attractors and repellors may be ... under user”, driver (or virtual operator) control.

Def. "[a]n object which draws the user [or vehicle] towards itself" is called an attractor.

Attractor dynamics
“[T]he dynamic approach to path planning ... can be implemented on simple autonomous vehicles using only low-level sensory information such as distances sensed by infra-red or sonar detectors. Each sensor is assumed to contribute a repulsive force-let to a dynamical system, which generates a trajectory of heading direction.” “The repulsion force is a decreasing function of sensed distance. This leads to obstacle avoidance.”

This “approach ... employs the heading direction, phi, relative to some external world axis, as the planning variable. The path plan is a time course of this variable ... obtained from a differential equation of heading direction.” “The sensors are arranged such that their sensitive cones just touch, thus covering completely the forward 180° semicircle.”

Repellors
“A repellor pushes [a vehicle or] the user away from itself, for example, in a direction of motion which extends radially from the center of the repellor.”

In the image at right, a small (~6 mm wide) piece of pyrolytic carbon is pushed away from an array of neodymium magnets with alternating polarity; i.e., diagonally identical magnetic orientation (two with north poles up and two with south poles up). The repellor vector is vertical from the central hole.

Magnetic materials and systems are able to attract or press each other apart or together with a force dependent on the magnetic field and the area of the magnets, with a defineable magnetic pressure.

The "directions in which obstacles are detected are [referred to as] local repellors.

Repellors can also be unstable fixed points.

A repellor either the driver or virtual controller must guard against is the formation of spurious attractors (or repellors).

Transport platforms
For a pilot or driver, the vehicle needs to contain or be part of the pilot or driver transport.

Probably the most common pilot or driver transport is an automobile or car. It usually has an internal combustion engine that uses the expansion of burning gases to mechanically propel the transport platform.

For such a platform to leave the roadway requires additional support for the driver/pilot to survive the rugged terrain.

Occasionally automobiles are propelled above the ground for brief periods using ramps. The return usually requires reinforced suspension systems to handle the acceleration downward.

For this type of platform to remain aloft would require separate propulsion and suspension for the descent.

These platforms are often used and kept running for decades. After such lengthy periods components are likely to fall off. Some include mufflers, hub caps, mud flaps, trim, and even tires. Depending on the climate, hot, dry deserts at sufficient elevation will cause the outer paint to bleach and peel off.

An older standard-size automobile is shown in the top image at the right. Its larger size allows for passengers. It is front-wheel drive with the engine compartment (shown in the second image at the right) above the front wheels. The transmission is approximately below the battery platform (red and black terminal covers).

Maintenance of the transmission, brakes, fuel line, oil and oil filter systems usually requires undercarriage access on a lift or jacks.

The rear compartment behind the passenger cabin houses a temporary spare tire and room for luggage.

The third image at the right is a passenger's side view of the front portion of the passenger cabin. The dashboard has a relatively open vertical area in front of the stick shift mechanism. Earlier models also had a shifting lever on the steering mechanism.

The large volume in front of the stick shift may be a likely location for additional cockpit controls.

Driverless cars
At left is an image of a Volkswagen Passat that drives itself. The roof is festooned with spinning LIDAR and cameras, feeding into the server farm in the trunk. This driverless car dates from October 24, 2009.

On the right is a trunk image of the hardware needed for the Volkswagen Passat that drives itself. For this car, Junior 3, the sensors are discrete rather than festooned on the roof. This image also dates from October 24, 2009.

A driverless car is a vehicle equipped with an autopilot system, and capable of driving from one point to another without aid from an operator.

Autonomous vehicles
“An autonomous vehicle is a virtual object, such as an elevator, which, once entered by the user, automatically moves the user to a new location in the virtual world.”

Notation: let the symbol AUV stand for autonomous underwater vehicle.

An autonomous underwater vehicle (AUV) is a robot which travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes non-autonomous remotely operated underwater vehicles (ROVs) – controlled and powered from the surface by an operator/pilot via an umbilical or using remote control. In military applications AUVs more often referred to simply as unmanned undersea vehicles (UUVs).

Driver assistive technologies
"There's adaptive cruise control, which keeps an eye on the car ahead and maintains a steady separation. Another system warns the driver if the car begins to stray outside its proper lane. And a few models even offer hands-free parallel parking."

Pilotless hovering vehicles
At right is a digitized photograph of a micro air vehicle designed to fly over a combat area during flight. As of November 14, 2006, the MAV is in the operational test phase with military Explosive Ordnance Disposal (EOD) teams to evaluate its short-range reconnaissance capabilities.

The small craft allows remote observation of hazardous environments inaccessible to ground vehicles. MAVs have been built for hobby purposes, such as aerial robotics contests and aerial photography.

The range of Reynolds numbers at which MAVs fly is similar to that of an insect or bird (103 - 105). Thus, some researchers think that understanding bird flight or insect flight will be useful to designing MAVs. The flapping motion used by birds and insects to produce lift involves aeroelasticity, which introduces structural considerations. Unsteady aerodynamics [may] also [be] present in this type of motion.

Pilotless aerial vehicles
The V-1 flying bomb the Fieseler Fi 103 is an early pulse-jet-powered predecessor of the cruise missile. In late 1936, Argus Motoren company had already developed a remote-controlled surveillance aircraft, the [Argus As 292] AS 292 (military designation FZG 43).

A culmination of the flying bomb effort is the SM-62 Snark shown in flight at right which is "an early-model intercontinental cruise missile that could carry a W39 thermonuclear warhead. The Snark has an operational range of 10,200 km.

After the successful development of the intercontinental ballistic missile (a pilotless rocket), the Snark and its kindred are replaced by the ~1,000 km ranged cruise missile.

Sense around systems
A sense around system is one that relates to the vehicle driver or operator information from all around the vehicle so that driving or operating decisions can be made.

Collision avoidances
In spaceflight, collision avoidance is the process of preventing a spacecraft from colliding with any other vehicle or object.

A launch window is said to have a [collision avoidance, or COLA] COLA blackout period during intervals when the vehicle cannot lift off to ensure its trajectory does not take it too close to another object already in space.

A collision avoidance manoeuvre  or Debris Avoidance Manoeuvre  (DAM) is an orbital manoeuvre conducted by a spacecraft to avoid colliding with another object in orbit. One is most commonly used in order to avoid a piece of space junk.

An airborne collision avoidance system (ACAS) is an aircraft system that operates independently of ground-based equipment and air traffic control in warning pilots of the presence of other aircraft that may present a threat of collision. If the risk of collision is imminent, the system indicates a manoeuvre that will reduce the risk of collision. ACAS standards and recommended practices are mainly defined in annex 10, volume IV, of the Convention on International Civil Aviation.

A distinction is increasingly being made between ACAS and ASAS (airborne separation assurance system). ACAS is being used to describe short-range systems intended to prevent actual metal-on-metal collisions. In contrast, ASAS is being used to describe longer-range systems used to maintain standard en route separation between aircraft (5 nm {9.25 km} horizontal /1000' {305 m} vertical).

A collision avoidance system is a system of sensors that is placed within a car to warn its driver of any dangers that may lie ahead on the road. Some of the dangers that these sensors can pick up on include how close the car is to other cars surrounding it, how much its speed needs to be reduced while going around a curve, and how close the car is to going off the road. The system uses sensors that send and receive signals from things like other cars, obstacles in the road, traffic lights, and even a central database are placed within the car and tell it of any weather or traffic precautions.

Toyota Motor Corporation's Pre-Collision System (PCS), the first production forward warning collision system, is used on the manufacturer's Lexus and Toyota brand vehicles. It is a radar-based system which uses a forward-facing millimeter-wave radar. When the system determines a frontal collision is unavoidable it preemptively tightens the seat belts removing any slack and pre-charges the brakes using brake assist to give the driver maximum stopping power instantly when the driver depresses the brake pedal.

Propulsion systems
A propulsion system is a machine or system of machines that produces thrust to push or pull a vehicle from a position of relative rest into motion or to provide an acceleration or deceleration for a vehicle already in motion. The objective of a propulsion system is to maintain the vehicle’s ability to propel itself and maneuver. Current propulsion systems are often some form of internal-combustion engine combined with aerodynamic lifting mechanisms.

Rocket engines such as the Pixel rocket shown at right have been developed which can hover a vehicle for brief periods.

On the ground and in the air the Waterman Aerobile at left is powered by a water-cooled 120 hp (89 kW) Tucker-Franklin engine. It can fly at 112 mph (180 km/h), cruise speed of 164 km/h, maximum speed of 193 km/h, and drive at 56 mph (90 km/h), with a maximum of approximately 113 km/h.

"Japanese electronics maker NEC Corp. on Monday showed a "flying car," a large drone-like machine with four propellers that hovered steadily for about a minute [in the second image down on the right]."

"The test flight reaching 3 meters (10 feet) high was held in a gigantic cage, as a safety precaution, at an NEC facility in a Tokyo suburb."

"The Japanese government is behind flying cars, with the goal of having people zipping around in them by the 2030s."

"Among the government-backed endeavors is a huge test course for flying cars that's built in an area devastated by the 2011 tsunami, quake and nuclear disasters in Fukushima in northeastern Japan."

"Similar projects are popping up around world, such as Uber Air of the U.S."

"The goal is to deliver a seamless transition from driving to flight like the world of "Back to the Future," although huge hurdles remain such as battery life, the need for regulations and safety concerns."

"Often called EVtol, for "electric vertical takeoff and landing" aircraft, a flying car is defined as an aircraft that's electric, or hybrid electric, with driverless capabilities, that can land and takeoff vertically."

"All of the flying car concepts, which are like drones big enough to hold humans, promise to be better than helicopters. Helicopters are expensive to maintain, noisy to fly and require trained pilots. Flying cars also are being touted as useful for disaster relief."

Capacitors
In the simple, ideal circuit on the right there is a capacitor (two equal parallel plates) with a resistor (rectangular box) and ammeter (A) in series, a voltmeter (V) in parallel, a switch (at the top) and a cell (two different length parallel plates) for charging.

A device that stores charge on one plate (thereby one charge carrier, say electrons) would first be charged by a cell using the left hand portion of the ideal circuit. When the switch is thrown to the right, electrons travel through the resistor and the ammeter (A) to neutralize the positive charge on the other parallel plate.

To prevent or greatly slow down charge drain the resistance of the resistor must be high. To have charge storage of electrons only, the positive plate must be reduced to neutral and the negative plate needs to be isolated from it.

Wound and stacked supercapacitors
Supercapacitors are constructed with two metal foils (current collectors), each coated with an electrode material such as activated carbon, which serve as the power connection between the electrode material and the external terminals of the capacitor. Specifically to the electrode material is a very large surface area. In this example the activated carbon is electrochemically etched, so that the surface of the material is about a factor 100,000 larger than the smooth surface. The electrodes are kept apart by an ion-permeable membrane (separator) used as an insulator to protect the electrodes against short circuits. This construction is subsequently rolled or folded into a cylindrical or rectangular shape and can be stacked in an aluminum can or an adaptable rectangular housing. Then the cell is impregnated with a liquid or viscous electrolyte of organic or aqueous type. The electrolyte, an ionic conductor, enters the pores of the electrodes and serves as the conductive connection between the electrodes across the separator. Finally the housing is hermetically sealed to ensure stable behavior over the specified lifetime.

Supercapacitor uses
"So far, supercapacitors have been good at providing quick bursts of power – to start a car engine, for example, or to give trains a boost when accelerating. They’re also suited to harvesting energy from vehicles when they brake, making them an important EV component."

"PSA Peugeot Citroen has been using [supercapacitors] in its cars since 2010."

"Supercapacitor maker Maxwell Technologies says more than a million vehicles now incorporate its products."

"Skeleton Technologies incorporates layers of graphene – a single layer of carbon atoms arranged in a hexagonal lattice – and other carbon-based materials in its supercapacitors."

"These layers have a huge surface area – just 1g of graphene can cover 2000 sqm."

"Short-term, combining supercapacitors with lithium-ion batteries is probably the way to enjoy the best of both worlds, particularly in EVs."

Automobiles
"Application of power electronics in automotive applications plays a major role in controlling automotive electronics. Automotive electronics include modern electric power steering, HEV main inverter, central body control, braking system, seat control, and so on."

"Applications of power electronics in automotive electrical and electronic systems includes high voltage systems, automotive power generation, switched mode power supply (SMPS), DC to DC converters, electric drives, traction inverter or DC to AC converter, power electronic component, high temperature requirement, application of SMPS in power train system, and so on. For example, consider a modern car, in which we can find many power electronic components such as ignition switch, control module, vehicle speed sensor, steering sensor and other components, as shown in [the figure on the right]."

Automobile Electric Power Systems
"Energy storage systems assisted by super capacitor have been widely researched and developed to progress power systems for the electronic vehicles."

The "system is able to perform adequate charge and discharge operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery."

Conduction "losses and voltage/current surge are drastically reduced by [zero voltage switching] ZVS operation with loss-less snubber capacitor in high voltage side as well as the synchronous rectification in low-voltage high-current super capacitor side."

"For these applications, bi-directional DC-DC converters to transfer the electric energy between low voltage S.C. based energy storage system and the high voltage drive train including three phase inverter-motor system and the main batter, are required as shown in [the diagram on the right]."

Batteries
An electric battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices.

When a battery is supplying electric power, its positive terminal as in the diagram on the right is the cathode and its negative terminal is the anode.

The terminal marked negative is the source of electrons that when connected to an external circuit will flow and deliver electrons to an external device. When a battery is connected to an external circuit, electrolytes are able to move as ions within, allowing the chemical reactions to be completed at the separate terminals and so deliver electrons to the external circuit. It is the movement of those ions within the battery which allows current to flow out of the battery to perform work.

For example, a battery rated at 100 A·h can deliver 5 A over a 20-hour period at room temperature.

Farads
The scale behind the one farad modern super-capacitor in the image on the right is in inches (top) and centimetres.

One farad (F) is defined as the capacitance across which, when charged with one coulomb, there is a potential difference of one volt. Equally, one farad can be described as the capacitance which stores a one-coulomb charge across a potential difference of one volt.


 * $$\text{F}

= \dfrac{\text{C}}{\text{V}} $$

The size of commercially available capacitors ranges from around 0.1 pF to 5 000  F (5 kF) supercapacitors.

The capacitance of the Earth's ionosphere with respect to the ground is calculated to be about 1 F.

For q = FV, 5000 * 1000 = 5,000,000 coulombs.

One coulomb is equivalent to the charge of approximately $6.242$ ($1.036$ mole protons, and −1 C is equivalent to the charge of approximately $6.242$ electrons.

So 5,000,000 coulombs = $3.1$ electrons.

Self-capacitance
In electrical circuits, the term capacitance is usually a shorthand for the mutual capacitance between two adjacent conductors, such as the two plates of a capacitor. However, for an isolated conductor there also exists a property called self-capacitance, which is the amount of electric charge that must be added to an isolated conductor to raise its electric potential by one unit (i.e. one volt, in most measurement systems). The reference point for this potential is a theoretical hollow conducting sphere, of infinite radius, with the conductor centered inside this sphere.

Mathematically, the self-capacitance of a conductor is defined by
 * $$C = \frac{q}{V},$$

where
 * q is the charge held by the conductor,
 * $$V = {1\over 4\pi\varepsilon_0}\int {\sigma \, dS\over r}$$ is the electric potential,
 * σ is the surface charge density.
 * dS is an infinitesimal element of area,
 * r is the length from dS to a fixed point M within the plate

Using this method, the self-capacitance of a conducting sphere of radius R is:


 * $$C=4\pi\varepsilon_0R \,$$

Example values of self-capacitance are:
 * for the top "plate" of a van de Graaff generator, typically a sphere 20 cm in radius: 22.24 pF,
 * the planet Earth: about 710 µF.

The inter-winding capacitance of an electromagnetic coil is sometimes called self-capacitance, but this is a different phenomenon. It is actually mutual capacitance between the individual turns of the coil and is a form of stray, or parasitic capacitance. This self-capacitance is an important consideration at high frequencies: It changes the electrical impedance of the coil and gives rise to parallel electrical resonance. In many applications this is an undesirable effect and sets an upper frequency limit for the correct operation of the circuit.

Electrostatic suspensions
Electrostatic suspension can occur whenever a voltage difference exists between two locations and a charged mass is within the space separating the two locations, where the amount of charge is sufficient to allow suspension or prevent contact with either location. The potential gradient is the local space rate of change of the electric potential, usually in units of volts per meter (V/m). An electric field is an electric potential of opposite sign. The Earth, for example, has a natural electric field.

"The upper electrodes are used to apply control voltages (228 V in nominal conditions). The lower electrode voltages are controlled to Vp [a dc voltage of about 10 V], so that no force attracts the mass toward the bottom."

For a gap of 0.00206 m, a proof mass of 5.40 g is successfully suspended against 1 G (of gravity) with a field of 7.7 x 106 V/m. The voltage on the proof mass is nominally 10 V.

A thin gold wire is attached at the bottom of the proof mass to allow charge or voltage to be added of removed from the proof mass. The mechanical core apparently including the proof mass is made of gold coated fused silica.

Hypotheses

 * 1) A supercapacitor-like device can be built and loaded aboard a platform to contain about 3300 coulombs of charge to allow the platform to be repelled from the Earth's surface.

Proof of mechanism
"Incorporating tracking studies into clinical trials of cell-based therapy at the earliest stage can provide proof of mechanism of the therapy and permit evaluation of the many contributory variables, even on a patient-by-patient basis."

"[B]iochemical markers [may be used] for early proof of mechanism"

"One early “proof of mechanism” study of farglitazar, a non-TZD PPARγ agonist, assessed 24-h insulin and glucose profiles in a double-blind, randomized, placebo-controlled study in patients with type 2 diabetes."