Transportation of electric vehicles

An electric vehicle is transported by an electric carrier whose motor is powered by the main power source—chargeable battery pack or fuel cell—of the transported electric vehicle.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to electric vehicles, and in particular to transportation of electric road vehicles.

Description of Related Art

The present disclosure resides at the crossroad between two major trends: electric vehicles and autonomous vehicles.

Electric vehicle, such as an electric passenger car or electric truck, uses a battery pack or fuel cell to supply electric power that powers an electric motor that drives the vehicle.

In an autonomous vehicle, sensors and compute are harnessed to aid or even replace a human driver in driving the vehicle.

While electric vehicles are gaining popularity toward dominating the market, autonomous vehicles face systemic safety problems that hinder their progress.

The present disclosure combines advancements in electric vehicles and autonomous vehicles to offer a comprehensive key toward attention-free or even driver-free vehicles.

SUMMARY OF THE INVENTION

Definitions

“Road vehicle” abbreviated “vehicle” is a motorized transportation means designed to carry passengers and/or cargo on paved roads. Cars and trucks are examples of road vehicles. “Electric vehicle” is a road vehicle driven by an electric motor.

“Way” herein is a transportation medium other than a paved road, for example a railway or waterway.

“Carrier” herein is a vehicle configured to carry a road vehicle on a way, for example a railcar or ferry.

Highlights

The present disclosure suggests that the safest and most practical autonomous vehicle is an electric vehicle transported by a railcar. Railcars run on rails separately from other traffic; they easily combine into trains that drive safely at high speed; and the car driver is relieved from any action or responsibility during the railed trip. Rail transport also benefits from a huge supportive industry, installed base and regulatory basis, as well as from a plethora of proven technologies, components, safety standards, and public trust.

Furthermore, the present disclosure suggests powering the railcars by electricity supplied by the carried electric vehicle, which offers at least two fundamental advantages: (1) eliminating the need to install, service and power a fail-safe electricity supply system, thereby highly reducing the costs of new railways dedicated to the transport of autonomous cars; and (2) avoiding the consumption of additional electricity at peak hours, and instead use electricity charged by electric cars at off-peak hours, typically overnight.

The present disclosure recognizes that the advantages of energizing carriers by carried vehicles extend beyond rail transportation. For example, a small electric ferry can transport an electric car across a river on demand; or an electric specialty vehicle with giant wheels can carry an electric car across a road obstacle. Both examples become economically feasible by eliminating the need to equip each carrier with sizeable rechargeable battery packs, provide a charging station connected to the grid, and maintain routine charging at off-peak hours.

BRIEF SUMMARY

According to preferred embodiments of the present invention, there is provided a system for transporting electric vehicles, the system including an electric vehicle, an electric carrier selected for transporting the electric vehicle over a way, and a transport control unit for controlling the electric carrier during transporting the electric vehicle.

The electric vehicle may include an electric vehicle motor for driving the electric vehicle; a main power source; a vehicle inverter for drawing DC power from the main power source and supplying variable frequency AC power for powering the electric vehicle motor; and a vehicle power delivery connection for delivering electric power to electric carriers.

The electric carrier may include a deck for supporting the electric vehicle; an electric carrier motor for driving the electric carrier; and a carrier power delivery connection for connecting to the vehicle power delivery connection and delivering electric power from the electric vehicle for powering the electric carrier motor while the electric carrier is transporting the electric vehicle.

The main power source of the electric vehicle is preferably either a rechargeable battery pack, or a fuel cell.

The electric vehicle may be an autonomous car having an autonomous car control unit, with the transport control unit forming part of the autonomous car control unit.

In a preferred embodiment, the electric power delivered from the electric vehicle for powering the electric carrier motor is variable frequency AC power supplied by the vehicle inverter. In another preferred embodiment, the electric power delivered from the electric vehicle for powering the electric carrier motor is DC power.

As an example, the way may be a waterway, with the electric carrier being an electric ferry. Or the way may be a railway, with the electric carrier being an electric railcar for carrying a single electric vehicle. Or the way may be a railway, with the electric carrier being an electric railcar for carrying at least two electric vehicles. Or the way may be a road obstacle, with the electric carrier being configured to carry an electric vehicle across the road obstacle. The above examples are not limiting.

There is also provided an electric carrier for transporting electric vehicles over a way. The electric carrier may include a deck for supporting at least one electric vehicle; an electric carrier motor for driving the electric carrier; and a carrier power delivery connection for connecting to each of the at least one electric vehicle for delivering electric power from each electric vehicle for powering the electric carrier motor while the electric carrier is transporting the at least one electric vehicle.

The electric carrier may further include a transport control unit for controlling the electric carrier during transporting the electric vehicle. The transport control unit may dynamically send to a vehicle inverter of each of the at least one electric vehicle, requests for AC power at varying specified frequencies. The electric carrier motor may then be powered by the AC power of the specified frequencies delivered from the vehicle inverter of each of the at least one electric vehicle.

In another embodiment, the electric carrier may have a carrier inverter, and the electric power delivered via the carrier power delivery connection is DC power converted by the carrier inverter to variable frequency AC power for powering the electric carrier motor.

There is also provided an electric vehicle for being selectably transported by a selectable electric carrier. The electric vehicle includes an electric vehicle motor for driving the electric vehicle; a main power source; a vehicle inverter for drawing DC power from the main power source and supplying variable frequency AC power for powering the electric vehicle motor; and a vehicle power delivery connection for delivering, to an electric carrier that transports the electric vehicle, electric power that is one of: (a) variable frequency AC power supplied by the vehicle inverter, or (b) DC power sufficient for driving the electric carrier.

The electric vehicle may also include a transport control unit for controlling the electric carrier during transporting the electric vehicle. Specifically, the electric vehicle may be an autonomous car having an autonomous car control unit, with the transport control unit forming part of the autonomous car control unit.

The vehicle power delivery connection may be for delivering DC power sufficient for driving the electric carrier, or for delivering variable frequency AC power supplied by the vehicle inverter.

There is also provided a method for transporting an electric vehicle on an electric carrier. The method includes: mounting the electric vehicle on the electric carrier; electrically connecting the electric carrier to the electric vehicle; delivering, from the electric vehicle to the electric carrier, electric power that is either DC power or variable frequency AC power supplied by a vehicle inverter; powering an electric carrier motor of the electric carrier by the electric power delivered from the electric vehicle; and transporting the electric vehicle by the electric carrier.

The electric power delivered from the electric vehicle to the electric carrier may be variable frequency AC power supplied by the vehicle inverter. The method then may further include: synchronously controlling the electric carrier and the vehicle inverter for transporting the electric vehicle.

Alternatively, the electric power delivered from the electric vehicle to the electric carrier may be DC power, and the method further includes: converting, by a carrier inverter, the DC power delivered from the electric vehicle to variable frequency AC power; powering the electric carrier motor by the variable frequency AC power supplied by the carrier inverter; and controlling the electric carrier for transporting the electric vehicle.

It will be noted that all variations above cover both single- and multiple-motor electric vehicles as well as single- and multiple-motor electric carriers.

DETAILED DESCRIPTION

Background Art

Reference is made toFIG.1Athat schematically describes an electric vehicle100A of the background art. Battery pack114is loaded from the grid104via AC charging connection108and AC-DC converter110that supplies DC charging current112to battery pack114. Battery pack114provides hi-voltage DC power118to DC-DC converter120that supplies low voltage DC battery charging current122to 12/24V battery124, which supplies low voltage power128to DC loads130such as lighting, multimedia systems, electronics, processors, and the like. Battery pack114also supplies hi-voltage DC current134to vehicle inverter138, which supplies variable frequency AC power140to electric vehicle motor144, the frequencies determined by inverter control unit136. Electric vehicle motor144is an AC motor that revolves at an RPM (revolutions per minute) determined by the instant AC frequency provided by vehicle inverter138, to drive, via transmission146the wheels of electric vehicle100A.

Notably, as of the time of the present disclosure, AC-DC converter110may offer, in some car models, bi-directional operation, so that AC charging connection108can be used to draw DC power from battery pack114and provide AC electricity to the grid, to a house, or to other loads. Vehicle-to-load 240V power output of some example cars ranges from 10A to 15A (2.4 kW to 3.6 kW). Some EVs, such as the Hyundai Ioniq 5 and Kia EV6, have a 3.6 kW power rating equivalent to a 15A outlet. The Ford F-150 lightning offers 9.6 kW via four AC outlets.

FIG.1Bschematically describes another version of electric vehicle100B of the background art, with battery pack114ofFIG.1Areplaced by fuel cell116, rendering AC-DC converter110and grid104ofFIG.1Aredundant. All other numbered elements ofFIG.1Bare the same as their corresponding elements inFIG.1A.

Simplified Layout

FIG.2depicts a simplified layout of a transportation system200taught by the present disclosure.

Electric vehicle204is operative to function similarly to electric vehicle100A or electric vehicle100B ofFIG.1A or1B, respectively. Main power source214is either battery pack114ofFIG.1Aor fuel cell116ofFIG.1B. Vehicle inverter238draws DC power from main power source214and powers electric vehicle motor244with variable frequency AC power controlled by inverter control unit236to ultimately determine the speed of electric vehicle204. DC-DC converter220coverts high-voltage DC power drawn from main power source214to 12 or 24V for charging 12/24 volt battery224, which is used to power DC loads such as lights, electronic, wipers, etc. Vehicle power delivery connection248includes wiring and connectors to deliver electric power to a selectable electric carrier260.

Electric carrier260is an electric device devised to transport electric vehicle204over way280. Deck268is any physical arrangement configured to support electric vehicle204when transported by electric carrier260. Transporter276driven by electric carrier motor272is any mechanism configured to drive and direct electric carrier260over way280. Nonlimiting examples include: (1) electric carrier260is a railcar, way280is a railway, and transporter276is the railcar driving wheels; (2) electric carrier260is a ferry, way280is a waterway, and transporter276is an electric outboard propeller that includes electric carrier motor272; and (3) electric carrier260is a specialty vehicle having giant wheels for crossing road obstacles, way280is a road water obstacle, and transporter276is an electric winch.

Carrier power delivery connection264includes wiring and connectors to deliver electric power from electric vehicle204for powering electric carrier motor272.

Vehicle-carrier power delivery connection250connects vehicle power delivery connection248and carrier power delivery connection264. It is essentially an electric cable of an appropriate length for its effective and convenient functionality. In some embodiments it may form part of electric carrier260. In other embodiments it may be null, where connectors at the ends of vehicle power delivery connection248and carrier power delivery connection264are devised to engage directly when electric vehicle204is mounted on electric carrier260.

A transport control unit, that forms part of either electric vehicle204as transport control unit282, or electric carrier260as transport control unit284, controls essential functionalities of electric vehicle204and electric carrier260to drive electric carrier260to a destination.

It will be noted that the power delivery system combining vehicle power delivery connection248, vehicle-carrier power delivery connection250and carrier power delivery connection264, is for powering electric carrier motor272. The same or different power delivery chain may function for delivering low-voltage electricity from 12/24 volt battery224to electric carrier260, for powering low-power elements of electric carrier260such as brakes, lights, electronics and/or processors, including transport control unit284. This note also applies toFIGS.2A-2D, and will not be repeated below.

Power Sources

Electric vehicle204ofFIG.2offers four electric power sources to choose from. The power capacities below represent electric vehicles as of the date of this patent application:(a) AC-DC converter210, is typically capable, in some car models fitted for bi-directional charging, of supplying a few kilowatts of 240V AC power for powering the grid, home essentials, or another moderate load.(b) Vehicle inverter238is typically capable of powering electric vehicle motor244with hundreds of kilowatts of variable frequency AC power, depending on the car model.(c) Main power source214(rechargeable battery pack or fuel cell) is typically capable of supplying hundreds of kilowatts of DC power to vehicle inverter238B.(d) 12/24 volt battery224supplies low DC power for small instruments, devices and electronics of the car.

The few kilowatts available from AC-DC converter210are generally insufficient for car transport. An example exception is transport for a very short distance at a very low speed, for example powering a small 240V AC motor of a few kilowatts coupled with a high reduction ratio gear to drive a specialty giant-wheel carrier for crossing a water road obstacle. This use case is described inFIG.2Abelow.

Vehicle inverter238or main power source214are the most potent power sources for driving electric carrier260, and will be described inFIGS.2B and2Cbelow.

12/24 volt battery224cannot provide sufficient electric power for electric carrier motor272. However, as noted above, it may still power low-power elements of electric carrier260such as lights, electronics and/or processors, including transport control unit284.

Delivering Low-Power AC from Vehicle to Carrier

FIG.2Adescribes system200A that makes use of the 50/60 HZ 240V electricity, such as AC power supplied by some electric car models via a bi-directional AC-DC converter210.

In system200A, electric power delivered from electric vehicle204A to electric carrier260A is AC power supplied by AC-DC converter210via vehicle power delivery connection248A, vehicle-carrier power delivery connection250A and carrier power delivery connection264A, through AC switch266A, to power transporter276A.

As long as the typical power available from AC-DC converters of some electric cars that feature bi-directional charging is of just a few kilowatts, the embodiment ofFIG.2Amay be suited for short-distance, low-speed use cases, for example where electric carrier260A is a specialty giant-wheel carrier for moving a vehicle across a road obstacle280A. In such cases, coupling AC motor272A of a few kilowatts power with high reduction ratio gear274may provide sufficient torque for driving transporter276A, such as by rotating giant wheels of electric carrier260A or actuating a winch that drives electric carrier260A.

Transport control unit284A controls AC switch266A.

Delivering Variable Frequency AC Power from Vehicle to Carrier

FIG.2Bdescribes system200B, where the electric power delivered from electric vehicle204B to electric carrier260B is variable frequency AC power supplied by vehicle inverter238B via vehicle power delivery connection248B, vehicle-carrier power delivery connection250B and carrier power delivery connection264B, to power electric carrier motor272B that drives electric carrier260B.

In the configuration of system200B, electric vehicle204B not only supplies power to electric carrier260B, but also effectively controls the speed of electric carrier260B, since the frequency of the variable frequency AC power supplied by vehicle inverter238B determines the RPM (revolutions per minutes) of electric carrier motor272B, which ultimately determines the speed of electric carrier260B. Accordingly, the transport control unit, implemented either as transport control unit282embedded in electric vehicle204B or transport control unit284embedded in electric carrier260B, synchronously controls both inverter control unit236to determine the speed of electric carrier260B, and transporter276B to affect other driving functionalities, such as braking and steering, where appropriate.

Delivering Dc Power from Vehicle to Carrier

FIG.2Cdescribes system200C, where the electric power delivered from electric vehicle204C to electric carrier260C is DC power. The DC power is either directly drawn from main power source214C, or may pass through a high-power DC-DC converter (not shown) to reduce voltage for technical or safety reasons. The DC power is delivered to carrier inverter290C via vehicle power delivery connection248C, vehicle-carrier power delivery connection250C and carrier power delivery connection264C. Carrier inverter290C then supplies variable frequency AC power to power and determine the RPM (revolutions per minute) of electric carrier motor272C. Transport control unit284C synchronously controls both carrier inverter290C to ultimately determine the speed of electric carrier260B, and transporter276B to affect other driving functionalities, such as braking or steering, where appropriate.

In some embodiments, electric carrier motor272C may be a DC motor, in which case carrier inverter290C is replaced by a DC motor control unit (not shown).

Autonomous Car

FIG.2Ddescribes system200D, that is similar to system200B ofFIG.2B, except that the electric vehicle is electric autonomous car204D that is controlled by autonomous car control unit278, and transport control unit282D forms part of the autonomous car control unit278.

Accordingly, in electric autonomous car204D, control unit278controls normal rides of the autonomous car on the road, as well as carried rides when the autonomous car is transported by an electric carrier controlled by autonomous car control unit278via its transport control unit282D.

EXAMPLES

FIG.3reviews several example embodiments340of system200ofFIG.2. In example344, the electric carrier is a railcar, and the way is a railway. In implementation344A the railway is laid on the ground; in implementation344B the railway is elevated above the ground; in implementation344C that railway is laid underground. Cases344D and344E refer to the use of dual rail or monorail in the implementations344A-344C.

In example348, the electric carrier is a ferry, and the way is a waterway. The ferry can be of a small size, to accommodate a single electric vehicle, or of a larger size, to accommodate several electric vehicles powering the electric ferry.

Example352pertains to a specialty electric carrier for carrying an electric vehicle across a road obstacle, such as a water obstacle. This case typically involves very short trips at a very slow speed, as described above with reference toFIG.2A.

Operation

FIG.4Adescribes a method of operating a system for transporting electric vehicles according to a preferred embodiment of the present invention.

In step404A an electric vehicle is mounted on an electric carrier. In step408A the electric carrier is electrically connected to the electric vehicle, so that electric power can be delivered from the carried electric vehicle to the electric carrier. In step412A, variable frequency AC power is delivered to the electric carrier from a vehicle inverter of the electric vehicle. In step416A, an electric carrier motor of the electric carrier is powered by the variable frequency AC power delivered from the electric vehicle. In step420A the electric vehicle is transported by the electric carrier driven by the electric carrier motor.

It will be noted that the powering of the electric carrier motor in step416A by variable frequency AC power delivered from the vehicle inverter of the electric vehicle is step412A, effectively makes the speed of the electric carrier determined by the instant frequency of the AC power delivered from the vehicle inverter.

FIG.4Bdescribes a method of operating a system for transporting electric vehicles according to another preferred embodiment of the present invention, with the electric power delivered from the transported vehicle to the transporting carrier being DC power.

In step404B an electric vehicle is mounted on an electric carrier. In step408B the electric carrier is electrically connected to the electric vehicle, so that electric power can be delivered from the carried electric vehicle to the electric carrier. In step412B, DC power from a main power source of the electric vehicle is delivered to the electric carrier. In step414B, a carrier inverter of the electric carrier converts the DC power received from the electric vehicle to variable frequency AC power. In step416B, an electric carrier motor of the electric carrier is powered by the variable frequency AC power supplied by the carrier inverter. In step420B the electric vehicle is transported by the electric carrier driven by the electric carrier motor.

FIG.4Cdescribes a method of operating a system for transporting electric vehicles according to still another preferred embodiment of the present invention, with the electric power delivered from the transported vehicle to the transporting carrier being DC power for powering a DC motor of the electric carrier.

In step404C an electric vehicle is mounted on an electric carrier. In step408C the electric carrier is electrically connected to the electric vehicle, so that electric power can be delivered from the carried electric vehicle to the electric carrier. In step412C, DC power from the electric vehicle is delivered to the electric carrier. In step416C, a DC electric carrier motor of the electric carrier is powered by the DC power delivered from the electric vehicle. In step420C the electric vehicle is transported by the electric carrier driven by the electric carrier motor.

FIG.4Ddescribes a method of operating a system for transporting electric vehicles according to still another preferred embodiment of the present invention, with the electric power delivered from the transported vehicle to the transporting carrier being AC power from an AC-DC converter of the electric vehicle.

In step404D, an electric vehicle is mounted on an electric carrier. In step408D, the electric carrier is electrically connected to the electric vehicle, so that electric power can be delivered from the carried electric vehicle to the electric carrier. In step412D, AC power is delivered to the electric carrier from an AC-DC converter of the electric vehicle. In step416D, an electric carrier motor of the electric carrier is powered by the AC power delivered from the AC-DC converter of the electric vehicle. In step420D, the electric vehicle is transported by the electric carrier driven by the electric carrier motor.

It will be noted that as long as AC power supplied by AC-DC converters of electric vehicles is of just a few kilowatts, the method ofFIG.4Dis for limited applications discussed above with reference toFIG.2A.

Power Delivery from Several Electric Vehicles

In some embodiments, an electric carrier may carry two (or more) electric vehicles. While a typical electric vehicle can provide 100 KW or more of power that is sufficient to transport, for example, several vehicles on a railcar, it may be the interest of the participating electric vehicle drivers to equally share the electric energy contributed for their joint ride. A technical way of doing so may be based on cyclic time sharing, wherein each vehicle delivers power to the carrier motor for, say, one minute, and is then disconnected and power is delivered to the carrier from the next vehicle in the cycle. Other methods known in the art for consolidating electrical power from multiple sources are beyond the scope of the present disclosure.

Examples of Railway Carriers

FIGS.5A-5Hdepict examples of railway electric carriers that are constructed and operate according to preferred embodiments of the present invention.

FIG.5Adepicts loaded electric carrier500A that is electric railcar520that transports electric vehicle504. A carrier motor of electric railcar520(not shown) is powered by electric vehicle504via vehicle power delivery connector508, vehicle-carrier power delivery connection512, and carrier power delivery connector524.

FIG.5Bdepicts loaded electric train500B that is a train of two loaded railcars ofFIG.5A.

FIG.5Cdepicts loaded electric train500C that is similar to loaded electric train500B ofFIG.5B, except that the second electric railcar520C is not loaded, and is towed and/or powered by electric railcar520. This configuration may be useful for returning empty railcars to loading points that face a shortage of railcars.

FIG.5Edepicts loaded electric carrier500E that is an extended electric railcar522that carries and is powered by two of electric vehicle504. Extended electric railcar522has a motor receiving power from the two electric vehicles via a two-port carrier power delivery connector526. Power delivery from two (or more) sources may be based, for example, on cyclic time sharing, wherein each electric vehicle delivers power to the electric carrier for, say, one minute, and is then disconnected and power is delivered to the electric carrier from the next electric vehicle in the cycle.

FIG.5Fdepicts loaded electric carrier500F where the extended electric railcar522is loaded with and powered by a single electric vehicle504.

FIG.5Gdepicts loaded electric carrier500G where the extended electric railcar522that carries and is powered by electric vehicle504, is loaded also with arbitrary cargo550.

FIG.5Hdepicts loaded electric train500H that includes two extended electric railcars carrying and powered by electric vehicles and also carrying arbitrary cargo.

Verifying Sufficient Electrical Energy in Advance

FIG.6is a flowchart depicting verifying in advance that an electric vehicle has and allocates a sufficient amount of electrical energy (kWh) in its main power source, for powering the electric carrier that transports the electric vehicle up to reaching a designated destination. The flowchart is to be preferably implemented in a transport control unit that is any of transport control unit282, transport control unit284, transport control unit284A, or transport control unit284C ofFIGS.2,2A-2C. Alternatively, the flowchart can be implemented in a separate access control system that controls access of electric vehicles to electric carriers.

In step604a request for a transport to a specified destination is received. In step608, an amount of kWh available and allocated for the transport is received from the vehicle or the driver. Often, the amount allocated for the transport may be smaller than the remaining kWh amount in the main power source, since there may be a need for reserving electrical energy available also for subsequent trips prior to recharging the battery pack or replenishing the fuel cell of the vehicle.

In step612the amount of kWh required to reach the destination, by the electric carrier carrying the electric vehicle, is estimated according to route, weight and distance data, preferably including a safety factor. In step616the available amount of step608is compared to the required amount of step612. If the available amount is sufficient, then in step632the electric vehicle commits to provide the available amount during the travel to the destination, and in step636the electric vehicle is mounted on the electric carrier.

If step616finds that the available amount is insufficient, yet the remaining amount of kWh in the main power source of the electric vehicle is sufficient, then step620negotiates with the electric vehicle driver providing the required amount, which may oblige the driver to change travel plans, turn off climate control, or recharge earlier than originally planned. If in step624the negotiation is successful, then steps632and636are executed. Otherwise, the transport is declined in step628for insufficient kWh supply for reaching the designated destination.

CONCLUSION

The present disclosure teaches transporting electric vehicles by electric carriers that are powered by the main power sources—rechargeable batteries or fuel cells—of the carried vehicles. This paradigm enables:A. Highly simplifying and reducing the costs of electric carriers, by eliminating onboard power sources for the carriers. For example, a small ferry that transports an electric car across a river on demand, does not require a sizeable battery pack of its own.B. Highly simplifying infrastructures and reducing their costs and daily service. For example, the ferry system above does not require a dedicated charging infrastructure, connection to the grid, and routine charging at off-peak hours overnight. Even more dramatically, carriers that are railcars require just plain light-duty rails, with no need for a fail-safe heavy-duty electricity supply system which is extremely expensive to acquire, install, service, and operate.C. Eliminating major additional peak-hour loads on the grid, which could be required for operating a new fleet of electric railcars powered conventionally.

Advantage A-C accumulate into enabling a new, practical breed of autonomous cars, as well as other new transportation instruments implemented as electric vehicles transported by electric carriers that are powered by the carried vehicles.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein. Rather the scope of the present invention includes both combinations and sub-combinations of the various features described herein, as well as variations and modifications which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.