Patent Description:
Electric vehicles, such as electric cars, are increasingly popular. The motor of the vehicle is typically powered by a battery when in use. Typically, the battery is charged when the vehicle is parked in for instance a parking lot or at home. A problem with this approach is that large and heavy batteries are needed in order to provide a long running time and the charging may be lengthy.

A solution to the above problem is to charge and/or power the electric vehicle while driving on a road. A common name for systems which provides such charging and/or powering is electric road systems.

<CIT> discloses a method for transferring electrical power inductively, in particular for charging a moving battery, wherein electrical power is transferrable between a primary coil and a secondary coil when said secondary coil is arranged relative to said primary coil in a way allowing inductive interaction between said secondary coil and said primary coil, wherein said electrical power is transferrable if said primary coil is switched to be connected to a power grid and wherein said electrical power is not transferrable if said primary coil is switched to be disconnected from said power grid, comprising the steps of - testing whether a condition for granting the transfer of power, in particular an authorization of an identification by a server, is met, and - switching at least two primary coils, depending on the result of a single test of said condition.

<CIT> discloses a system for driving an electric and by one or more batteries powered vehicle along a roadway, comprising "a" one or more vehicles, which may be driven by an individual electric motor or motors and where in the respective vehicles exhibit a power-controlling control circuit for creating the necessary power and/or speed control and wherein required power i.e. can be provided primarily by a chargeable can be provided primarily by a chargeable battery set associated with the vehicle and "b" a plurality of road sections road portions divisible for the roadway, each being allotted one or more vehicle external electric stations for charging the battery set thereby and/or for supplying necessary power and energy for driving the vehicle. The underneath side of the mentioned vehicle is provided with a contact means displaceably positioned up and down and sideways, counted in the direction of transportation. Said roadway and its road sections or portions exhibits an elongated track or groove, each road section is supporting two rails in the groove and disposed under the driving path of the road section or portion. The rails being supplied with current and voltage. Said contact means is coordinated with a control equipment for creating simple adaptation of the contact means for registering the contact means for mechanical and electrical contact against said two rails.

<CIT> discloses an inductive energization system for moving vehicles includes wayside inductors under the roadway and pickup inductor circuits in electrically powered vehicles. A pickup power controller has a switching circuit, including a zero-crossing trigger circuit, a current limiting inductor, and a bleed resistor. The controller provides for fast switching, desirable for closed loop control of the inductive energy transfer system, as well as low harmonic distortion of waveforms, low acoustic noise, and low maintenance requirements. The pickup inductor of the preferred embodiment has rigid metal conductors bonded together into a single member, allowing this element to serve as both a current carrying element as well as a primary structural member of the pickup inductor. The roadway inductor is split into many segments. Sensors in the roadway detect when vehicles requiring power are present, and a wayside inductor segment controller responds to the sensory signals by energizing only those wayside inductor segments needed to transfer power to such vehicles. This control methodology improves the energy efficiency of the system. In addition, the roadway sensors can be designed to detect identification signals broadcast by vehicle identification transmitters, thereby enabling the system to charge for energy usage by each vehicle.

<CIT> discloses a communication system for a vehicle on a section of a roadway, the system comprises a vehicle communication unit installed on the vehicle, the vehicle communication unit wirelessly communicates through a magnetic field signal; a plurality of roadway communication units disposed under a surface of the roadway within the section, each roadway communication unit wirelessly communicating with the vehicle communication unit through the magnetic field signal and outputting a first data including an information on a speed of the vehicle; and a gateway node disposed at the roadway, communicating with the roadway communication units and outputting a second data. The gateway node receives the first data from the roadway communicating units, estimates a location where the vehicle reaches at a preset moment by using the speed of the vehicle, and controls one or more of the roadway communication units near the estimated location such that said one or more of the roadway communication units wirelessly transmit the second data to the vehicle.

<CIT> discloses a method for controlling the charging of segments for an online electric vehicle. In some situations, the method comprises: (a) receiving, from segments, information on the speed and position of the vehicle entering the range of the power-supplying device; and (b) controlling the charging/discharging timing of the current segment from which the vehicle is leaving and the next segment into the range of which the vehicle is to enter, in accordance with the information on the speed and position of the vehicle. The charging/discharging response delay characteristics of the segments may be considered.

<CIT> discloses systems, methods, and apparatus for wirelessly charging an electric vehicle. In one aspect, a method of wirelessly charging an electric vehicle is disclosed. The method includes generating a wireless field at a power level sufficient to charge the electric vehicle by at least one charging circuit comprising at least on coil. The method further includes detecting an arrival of the electric vehicle at the at least one charging circuit, the detection of the arrival of the electric vehicle determined based on a level of current flowing through the at least one coil. The method further includes generating a proximity signal upon the detection of the arrival of the electric vehicle at the at least one charging circuit.

<CIT> discloses a transportation system for use with a roadway including conductive sections along the roadway so that electric vehicles having a motor and two or three contact members which contact the conductive sections to provide power. The conductive sections have spaces therebetween to prevent short circuiting by the contact members. Alternate sections are connected continuously to a reference voltage and the remaining sections are either directly connected to a source of D. power or through a switching device operable to connect them to any suitable power source when the vehicle is proximate thereto. When three contact members are used, the spacing therebetween is such that two of the three conductors always contact oppositely poled sections and no two conductors can contact a space between sections simultaneously. motor is used, unidirectional current flow means may be also employed to assure that the current flows to the motor always in the same direction.

A problem for electric road systems is to provide electrical safety, especially in urban areas. Electrically chocking people interacting with the electric road system shall be avoided.

Another problem for electrical road systems is the billing of users using the system. It must be safeguarded that it is the right user that is billed for his outtake of electricity from the system.

Thus, there is an evident need for improving known electric road systems.

It is an object of the present invention to at least partly address the challenges discussed above.

According to a first aspect a method for activating a segment for enabling electrical power delivery to vehicles is provided. The segment being one of a plurality of segments consecutively arranged along a single track line of an electric road system that further comprises a base station. The method comprises receiving, at the base station, identification data transmitted from a vehicle, the identification data identifying the vehicle; associating an activation key with the identification data; transmitting the activation key from the base station to the segment; receiving, at the segment and via short range radio communication, an activation request sent from the vehicle, wherein the activation request comprises an identification key associated with the identification data; confirming, at the segment, that the received identification key is associated with the received activation key; upon positive confirmation, activating the segment for enabling power delivery to the vehicle.

By providing the vehicle and the segments with the identification key and the activation key respective provide for quick activation of the segments upon the vehicle approaching. The segments are already prepared and warned that the vehicle will arrive soon. Moreover, the method provides for separating power outtake for different vehicles. This since each vehicle identifies itself in order to activate segments of the electric road system. Moreover, the segments of the electric road system may be individually activated and monitored. Providing for that segments that are not in use may be switched off. The method also provides for individual measurement of power out take from the electric road system, hence, each vehicle's power consumption may be monitored providing an individual payment solution.

The method further comprise, upon positive confirmation, transmitting a deactivation request from the segment to a previously activated segment of the plurality of segments. The previously activated segment may be a nearby segment. The term "nearby" shall in this context be construed as a segment being located at maximum four segments away from the present segment. This provide for a deactivation of previously powered segments. Hence, an increased safety of the electric road system is achieved.

The method may further comprise determining a speed of the vehicle; determining an activation time period based on the determined speed of the vehicle and a length of the segment; wherein the segment is set to be active during a time period corresponding to the activation time period. This provide for a deactivation of powered segments in an alternative manner. Hence, an increased safety of the electric road system is achieved.

The method may further comprise storing the, with each other associated, identification key, activation key and identification data in a database.

The method further comprise measuring power delivered by the powering segment while activated; and storing the measured delivered power in the database in association with the identification data. This provide for that the vehicle itself does not have to keep track of how much power it draws from the electric road system but the electric road system itself monitors and stores the consumption of each vehicle. This allow for the electric road system to keep track of payment schedule for the vehicles. Moreover, an electric road system that does not rely on the vehicle's log systems for consumed energy avoids the problem of "energy thieves". Moreover, in this manner the system may e.g. deny power outtake if for example a previous bill is not paid.

One or more of the acts of receiving identification data, and transmitting the activation key is performed via a mid-range radio communication, wherein the mid-range radio communication is a radio communication having a range of at least <NUM> meters, preferably a range of at least <NUM> meters.

In this context the terms "active" shall be construed as that a segment of the first set of segments is in a state wherein it may deliver electric power to the vehicle. Hence, a segment of the first set of segments is active as long as the segment is set to have a potential being different from ground. Moreover, in this context the terms "activate or activating" shall be construed as to the action of setting a segment of the first set of segments to a potential different from ground. Furthermore, in this context the terms "deactivate or deactivating" shall be construed as to the action of setting an active segment into a non-active state. Hence, the active segment is controlled such that the potential is set to ground.

According to a second aspect an electric road system for enabling electrical powering of vehicles is provided. The electric road system comprises a plurality of segments consecutively arranged along a single track line, wherein every second of the plurality of segments belong to a first set of segments; and a base station. The base station comprises a receiver configured to receive an identification message, the identification message comprising identification data identifying a vehicle; an association module configured to associate the identification data with an activation key; and a transmitter module configured to transmit the activation key to the segments in the first set of segments. Each segment in the first set of segments comprises a receiver configured to receive the activation key; a memory configured to store the received activation key; a short range radio communication receiver configured to receive an activation request from the vehicle, the activation request comprising an identification key associated with the identification data; an authorization module configured to confirm that the received identification key is associated with the received activation key; and an activation module configured to, upon positive confirmation, activate the segment for enabling power delivery to the vehicle.

The above-mentioned features of the method according to the first aspect, when applicable, apply to this second aspect as well. In order to avoid undue repetition, reference is made to the above.

Each segment in the first set of segments further comprise a transceiver configured to, upon positive confirmation, transmit a deactivation request from the segment to a nearby segment in the first set of segments; and a deactivation module configured to, upon receipt of a deactivation message, deactivate the segment for disabling power delivery to the vehicle.

The electric road system may further comprise a database configured to store the associated identification key, activation key and identification data.

Each segment in the first set of segments further comprise a measuring module configured to measure power delivered by the segment while the segment is active; and a transmitter configured to transmit the measured delivered power to the database for storing the measured delivered power therein in association with the identification data.

According to a third aspect, not forming part of the present invention, a method for electrically powering a vehicle by an electric road system that comprises a plurality of segments consecutively arranged along a single track line and a base station is provided. The method comprises transmitting, from the vehicle to the base station, identification data identifying the vehicle; setting, at the vehicle, an identification associated with the identification data; transmitting, from the vehicle to at least one of the plurality of segments and via short range radio communication, the identification key; and collecting, at the vehicle, power from said at least one of the plurality of segments.

The above-mentioned features of the method according to the first aspect or the system according to the second aspect, when applicable, apply to this third aspect as well. In order to avoid undue repetition, reference is made to the above.

According to a fourth aspect, not forming part of the present invention, a vehicle configured to receive electric power from an electric road system that comprises a plurality of segments consecutively arranged along a single track line and a base station is provided. The vehicle comprises a transmitter configured to transmit identification data identifying the vehicle to the base station; a memory configured to store an identification key associated with the identification data; a short range radio communication transmitter configured to transmit the identification key to at least one of the plurality of segments; and an electrical power collector configured to collect electrical power from said at least one of the plurality of segments.

The above-mentioned features of the methods according to the first or third aspects or the system according to the second aspect, when applicable, apply to this second aspect as well. In order to avoid undue repetition, reference is made to the above.

Hence, it is to be understood that this invention is not limited to the particular component parts of the device described or steps of the methods described as such device and method may vary.

The above and other aspects of the present invention will now be described in more detail, with reference to appended drawings showing embodiments of the invention. The figures should not be considered limiting the invention to the specific embodiment; instead they are used for explaining and understanding the invention.

An electric road system is illustrated in <FIG>. The electric road system is mounted on a road surface <NUM>. In <FIG> an electric vehicle <NUM>, here in the form of an electric car, is travelling on the road in the direction indicated by <NUM>. The electric road system comprises an electric road track <NUM> which extends along the intended travelling path of the road.

The general function of the electric road system is that it provides electrical power to electric vehicles travelling along the road. Thus, a battery of the electric vehicle can be charged while the electric vehicle is travelling on the road. Alternatively, or in combination, the motors of the electric vehicles can be continuously powered by electricity. For powering and/or charging the electric vehicle <NUM> the electric road system is according to this embodiment arranged to provide power through the electrical road track <NUM> to which power collectors 14a, 14b, 14c of the car <NUM> can connect. Hence, according to this embodiment the electrical power is conducted from the electrical road track <NUM> to the electric vehicle <NUM>.

The electrical road track <NUM> forms a single track line comprising a plurality of segments 30a, 30b. The segments 30a, 30b are separated along the track line by electrically isolating members <NUM>. The segments 30a, 30b and the isolating members <NUM> may be arranged in a housing <NUM>. Every second segment 30a is configured to be powered by a power station <NUM>. The segments 30a configured to be powered by a power station <NUM> form a first set of segments 30a. The power station <NUM> may e.g. be located at the side of the road. The power station <NUM> is connected to the electrical road track <NUM> via conductors 15a, 15b. Upon being powered by a positive potential segment from the first set of segments 30a forms a positive pole. The other segments 30b form a second set of non-powered segments 30b. The non-powered segments 30b may be set to have the same potential as ground. Alternatively, a segment of the first set of segments 30a may be powered by a negative potential and thus form a negative pole. Upon powering one of the segments 30a of the first set of segments, a voltage difference is created between the powered segment 30a and the non-powered segments 30b. Hence, the single track line is segmented into a plurality of segments arranged to provide alternating potentials.

The power collectors 14a, 14b, 14c are arranged such that, at any moment during travelling, at least one of the power collectors 14a, 14b, 14c is in connection with a segment 30a of the first set of segments 30a and at least one other of the power collectors 14a, 14b, 14c is in connection with a segment 30b of the second set of segments 30b. Thus, continuous collection of power from the electrical road track <NUM> may be achieved upon the segments 30a of the first set of segments 30a are being powered.

The electrical road track <NUM> extends <NUM>-<NUM> along the road. The segments 30a, 30b have a length, along an extension in the traveling direction <NUM> of the vehicle, being shorter than a length of the vehicle <NUM>. According to a non-limiting example the length of the segments 30a, 30b are around <NUM> long. The electrically isolating member <NUM> may be about <NUM>-<NUM> long. A plurality of electrical road tracks <NUM> can be arranged after each other. As can be seen in <FIG>, two electric road tracks <NUM> are arranged after each other.

In <FIG> a portion of the electric road system of <FIG> is seen from the side. In addition to what is disclosed in connection with <FIG> the electric road system further comprises a base station <NUM>. The base station <NUM> may be arranged in the power station <NUM>. Alternatively, the base station <NUM> may be arranged as a standalone station separate from the power station. Yet alternatively, the base station <NUM> may be arranged in an aggregate together with other infrastructure related to a road, non-limiting examples of such other infrastructure are road signs, information displays, red lights and lamp-posts. The electric road system may further comprise one or more base stations <NUM>. Each base station <NUM> may be associated with one or several power stations <NUM>.

The base station <NUM> is in a segment communication connection with each segment 30a of the first set of segments 30a. The base station <NUM> may transmit data to the segments 30a over the segment communication connections. Each of the segments 30a may transmit data to the base station <NUM> over the respective segment communication connection. The segment communication connections may be wired connections. Alternatively or in combination, the segment communication connections may be wireless connections.

The base station <NUM> may also establish vehicle communication connections with vehicles. The base station <NUM> may transmit data to the vehicles over the vehicle communication connections. A vehicle may transmit data to the base station <NUM> over a vehicle communication connection. The vehicle communication connections are wireless connections.

In <FIG> the base station <NUM> is illustrated in more detail. The base station <NUM> comprises a receiver <NUM>, an association module <NUM> and a transmitter <NUM>. The base station <NUM> may further comprise a base station processor <NUM>. The base station <NUM> may further comprise a computer memory <NUM>. The base station <NUM> may further comprise a database <NUM>.

The base station processor <NUM> may be arranged to process data of the base station receiver <NUM>, the association module <NUM>, the base station transmitter <NUM> and/or the database <NUM>. Further, the base station processor <NUM> may be arranged to control flow of data between the receiver <NUM>, the association module <NUM>, the transmitter <NUM> and/or the database <NUM>.

The receiver <NUM> is configured to receive data sent over a vehicle communication connection. Especially, the receiver <NUM> is configured to receive an identification message from a vehicle over a vehicle communication connection. The identification message comprises identification data identifying a vehicle. The identification data may be in the form of an identification key. Alternatively, the identification data may be data from which the identification key may be derived. Still alternatively, the identification key may be generated by the base station and associated with the identification data and transmitted to the vehicle. The vehicle communication connection is preferably a mid-range radio communication. Hence, the receiver <NUM> is configured to receive data sent over a mid-range radio communication. Preferably, the mid-range radio communication has a range being at least <NUM> meters. Non-limiting examples of mid-range radio communication protocols is one of the group of protocols comprising IEEE <NUM> p, ITSG5, <NUM>, <NUM>, and <NUM>.

The association module <NUM> is configured to associate the identification data and/or the identification key with an activation key. In case the identification data is data from which the identification key may be derived, the association module <NUM> may be configured to derive the identification key from the identification data. As a non-limiting example, the identification key and the activation key are the same key. However, the identification key and the activation key may as well be different keys as long as they are associated with each other. The identification data and the activation key associated with each other are stored in the database <NUM>. The association module <NUM> may be implemented as a hardware module, a software module being executed by a processor or a combination of both hardware and software.

The database <NUM> may be comprised in the base station <NUM>. Alternatively, the database <NUM> may be partly comprised in the base station. In case the database <NUM> is partly comprised in the base station <NUM>, the database <NUM> is a distributed database <NUM> distributed over a plurality of devices. The plurality of devices may comprise base stations and/or other suitable devices. The database <NUM> or the part of the database <NUM> may be stored in the computer memory <NUM>.

The transmitter <NUM> may comprise first and second transmitter modules 43a, 43b. The first and second transmitter modules 43a, 43b may be the same transmitter module. The first and second transmitter modules 43a, 43b may be different transmitter modules. The first transmitter module 43a is configured to transmit the, from the identification data derived, identification key to the vehicle. Alternatively, or in combination, the first transmitter module 43a may be configured to transmit a confirmation that the identification data is associated with the activation key. Preferably, the first transmitter module 43a is configured to transmit the identification key to the vehicle over the vehicle communication connection. Hence, preferably the transmitter module 43a is configured to be a mid-range radio communication transmitter module. The second transmitter module 43b is configured to transmit the activation key to the segments 30a in the first set of segments 30a. The second transmitter module 43b is configured to transmit the activation key to the segments 30a in the first set of segments 30a over the segment communication connections. As mentioned above the segment communication connections may be wired connections or wireless connections. In case of wireless connections, the segment communication connections are preferably mid-range radio communications. Hence, the second transmitter module 43b may be configured to transmit data over mid-range radio communications.

In <FIG> a segment 30a of the first set of segments 30a is illustrated in more detail. Each segment 30a in the first set of segments 30a comprises a receiver <NUM>, a memory <NUM>, a segment processor <NUM>, a short range radio communication receiver <NUM>, an authorization module <NUM> and an activation module <NUM>.

The receiver <NUM> is configured to receive the activation key. Especially, the receiver <NUM> is configured to receive the activation key from the base station <NUM> over one of the segment communication connections. Hence, the receiver <NUM> is either configured to receive the activation key over a wired connection or over a wireless connection.

The memory <NUM> is configured to store the received activation key. A memory <NUM> of a single segment 30a of the first set of segments 30a may be configured to store more than one activation key.

The short range radio communication receiver <NUM> is configured to establish a short range radio communication connection with a vehicle. Preferably, the short range radio communication connection has a range being substantially the same as a length of the segment 30a. The short range radio communication may have a range of <NUM> to <NUM> meters. The short range radio communication is preferably one radio communication from the group of radio communications comprising: IrDA, Wireless USB, Bluetooth, Radio Frequency Identification (RFID), Z-Wave, and ZigBee. The short range radio communication receiver <NUM> is configured to receive an activation request. The activation request comprises the identification key.

The authorization module <NUM> is configured to confirm that the received identification key is associated with the received activation key. According to a non-limiting example the identification key and the activation key are the same key and hence the authorization module <NUM> is configured to compare identification key and the activation key to see if they are the same key. Other implementations known to a person skilled in the art on how to confirm that a key is associated with another key may as well be used. The identification key and the activation key may for example be complementary keys together forming a check sum. The authorization module <NUM> may be implemented as a hardware module, a software module being executed by a processor or a combination of both hardware and software.

The activation module <NUM> is configured to, upon positive confirmation by the authorization module <NUM>, activate the segment for enabling power delivery to the vehicle. The activation module <NUM> may be implemented as a hardware module, a software module being executed by a processor or a combination of both hardware and software.

Each segment 30a in the first set of segments 30a may further comprise a segment-to-segment transceiver <NUM> and a deactivation module <NUM>. The segment-to-segment transceiver <NUM> is configured to establish a segment-to-segment connection with another segment 30a in the first set of segments 30a. The segment-to-segment connection may be a wired connection or alternatively a wireless connection. The segment-to-segment transceiver <NUM> is configured to, upon positive confirmation by the authorization module <NUM>, transmit a deactivation request from the segment 30a to a nearby segment 30a in the first set of segments 30a. The segment-to-segment transceiver <NUM> is further configured to receive deactivation requests from nearby segments 30a of the first set of segments 30a. The deactivation module <NUM> is configured to, upon receipt of the deactivation message, deactivate the segment 30a for disabling power delivery. The deactivation module <NUM> may be implemented as a hardware module, a software module being executed by a processor or a combination of both hardware and software.

Each segment 30a in the first set of segments 30a may further comprise a measuring module 39a and a transmitter 39b. The measuring module 39a is configured to measure power delivered by the segment 30a while activated for power delivery. The measuring module 39a may be implemented as a hardware module, a software module being executed by a processor or a combination of both hardware and software. The transmitter 39b is configured to, via a database communication connection, transmit the measured delivered power to the database <NUM>. The database communication connection may be a wired connection. Alternatively, the database communication connection may be a wireless connection. The database <NUM> is further configured to store the measured delivered power in association with the identification data.

The segment processor <NUM> may be arranged to process data of the receiver <NUM>, the memory <NUM>, the short range radio communication receiver <NUM>, the authorization module <NUM>, the activation module <NUM>, the segment-to-segment transceiver <NUM>, deactivation module <NUM>, the measuring module 39a and/or the transmitter 39b. Further, the segment processor <NUM> may be arranged to control flow of data between the receiver <NUM>, the memory <NUM>, the short range radio communication receiver <NUM>, the authorization module <NUM> and the activation module <NUM>, the segment-to-segment transceiver <NUM>, deactivation module <NUM>, the measuring module 39a and/or the transmitter 39b. Of course the receiver <NUM>, the memory <NUM>, the short range radio communication receiver <NUM>, the authorization module <NUM> and the activation module <NUM>, the segment-to-segment transceiver <NUM>, deactivation module <NUM>, the measuring module 39a and/or the transmitter 39b may send data to each other without going via the segment processor <NUM>.

Data between two segments 30a, 30b may be sent to each other via the base station <NUM>.

In <FIG> a vehicle <NUM> configured to interact within the electrical road system is shown. The vehicle <NUM> is configured to receive electric power from the electric road system. The vehicle <NUM> comprises a transmitter 16a, a receiver 16b, a short range radio communication transmitter <NUM> an electrical power collector <NUM>, and a memory <NUM>.

The transmitter 16a is configured to transmit an identification message. The identification message comprises the identification data identifying the vehicle. As discussed above, the identification data may be in the form of the identification key. Alternatively, the identification data may be data from which the identification key may be derived. The transmitter 16a is configured to transmit the identification message to a base station <NUM>. The transmitter 16a is preferably configured to send data over the vehicle communication connection.

The receiver 16b may be configured to receive an identification key sent from the base station <NUM>. Alternatively, or in combination, the receiver 16b may be configured to receive a confirmation message from the base station <NUM>. The confirmation message comprising information confirming that the identification data is associated with the activation key. The receiver 16b is preferably configured to receive data sent over the vehicle communication connection.

The memory <NUM> is configured to store the identification data and the identification key. As mentioned above for some embodiments the identification data is in the form of the identification key and for some embodiments the identification data and the identification keys are different data stored in the memory.

The short range radio communication transmitter <NUM> is configured to transmit an activation request, comprising the identification key, to at least one of the plurality of segments 30a of the first set of segments 30a. The short range radio communication transmitter <NUM> may be arranged on an underside of the vehicle. The short range radio communication transmitter <NUM> may be arranged on the electrical power collector <NUM>. Preferably, the short range radio communication transmitter <NUM> is configured to transmit the activation request to a single one of the segments 30a of the first set of segments 30a at a time. The identification key is sent to the segment 30a for activation of the segment 30a to deliver electrical power to the vehicle.

The electrical power collector <NUM> is configured to collect electrical power from an activated segment. The electrical power collector <NUM> may be arranged as discussed in connection with <FIG>; hence, being configured to conductively pick up electrical power from the electrical road track <NUM>. If so the, electrical power collector <NUM> preferably comprises a plurality of electrical power collectors 14a, 14b, 14c, as illustrated in <FIG>. The smallest distance between two of the plurality of electrical power collectors 14a, 14b, 14c is preferably shorter than the length of the segments 30a, 30b. Alternatively, the electrical power collector <NUM> may be configured to inductively pick up electrical power from the electrical road track <NUM> (for this embodiment the electrical road track <NUM> is set up to transfer electrical power via induction, see below).

In connection with <FIG> a method for activating a segment 30a of the first set of segments 30a for enabling electrical power delivery to vehicles is illustrated. The method comprises the following acts. The act does not necessarily need to be performed in the order listed below. Receiving S600, at the base station <NUM>, identification data transmitted from a vehicle, the identification data identifying the vehicle. Associating S602 an identification key, an activation key and the identification data with each other. Transmitting S606 the activation key from the base station to the segment 30a to be activated. Preferably, the activation key is transmitted S606 to all the segments 30a of the first set of segments 30a. Receiving S608, at the segment 30a to be activated and via short range radio communication, an activation request sent from the vehicle. The activation request comprises the identification key. Confirming S610, at the segment 30a to be activated, that the received identification key is associated with the received activation key. Upon positive confirmation, activating S612 the segment 30a to be activated for enabling power delivery to the vehicle. Preferably, only a single one of the set of segments 30a may be activated at a single point in time under the influence of the identification key. More preferably, only a single one of the set of segments 30a being located underneath the vehicle is activated at the single point in time. However, more than one segment 30a of the first set of segments 30a may be active at the same point in time.

The identification key may only be used ones for activating a specific segment 30a of the first set of segments 30a. In this way it is made harder for another vehicle to listen for identification keys and reuse them on the expense of the vehicle being the true receiver of the activation key. Only the vehicle that first activates a segment may receive power from the electric road system. However, it is still possible to activate downstream, in the traveling direction of the vehicle, segments <NUM> of the first set of segments 30a using the same identification key.

The method may further comprise transmitting S604 the identification key from the base station to the vehicle. Is so, the identification key may be derived, at the base station, from the identification data.

The method may further comprise transmitting a confirmation message to the vehicle that the identification data is associated with the activation key. If so, the identification data is preferably the identification data is in the form of the identification key.

The method may further comprise, upon positive confirmation, transmitting S614 a deactivation request from the activated segment 30a to a nearby active segment 30a of the first set of segments 30a. The nearby active segment 30a has been previously activated for enabling power delivery to the vehicle. Hence, two, or even more, adjacent segments 30a of the first set of segments 30a may be simultaneously active. Upon activation of a downstream, in the traveling direction <NUM> of the vehicle, segment 30a, the deactivation request is sent to an upstream, in the traveling direction <NUM> of the vehicle, segment 30a. However, only a single segment 30a of the first set of segments 30a is activated by the identification key at the same point in time.

The method may further comprise determining S611A a speed of the vehicle; and determining S611B an activation time period based on the determined speed of the vehicle and a length of the segment. Wherein the act of activating S612 is performed during a time period corresponding to the activation time period.

The method may further comprise, deactivating the activated segment upon detecting that power is collected from the segment and thereafter detecting that power no longer is collected from the segment. That power first is collected from the segment 30a and that thereafter power is no longer collected from the segment 30a is indicating that the vehicle has passed the segment 30a. Hence the segment shall be deactivated.

The method may further comprise storing S603 the with each other associated identification key, activation key and identification data in a database.

The method may further comprise measuring S616 power delivered by the segment while activated. Storing S618 the measured delivered power in the database in association with the identification data.

In connection with <FIG> a method for electrically powering a vehicle by the electric road system is illustrated. The method comprises the following acts. The act does not necessarily need to be performed in the order listed below. Transmitting S700, from the vehicle <NUM> to the base station <NUM>, identification data identifying the vehicle <NUM>. Setting S702, at the vehicle <NUM>, an identification key associated with the identification data. The act of setting may comprise receiving the identification key from the base station, wherein the identification key is derived at the base station from the identification data. The act of setting may comprise setting the identification data as the identification key, wherein the identification data forms the identification key. Transmitting S704, from the vehicle <NUM> to at least one of the plurality of segments 30a of the first set of segments 30a and via short range radio communication, the identification key. Collecting S706, at the vehicle, power from said at least one of the plurality of segments 30a.

For example, instead of or in combination with providing the electrical power to the electric vehicle conductively, the electrical road track <NUM> may be set up to transfer electrical power to the electrical vehicle via induction (not shown). For this set up of the electrical road system the segments 30a 30b are arranged as inductive powering segments.

Moreover, as illustrated in <FIG> the electric road system may comprise a plurality of base stations <NUM>. The plurality of base stations <NUM> are controlled by a control server <NUM>. Each of the plurality of base stations <NUM> may be connected to the control server by wire of wirelessly. The database, or portions of the database, may be arranged in a control server <NUM>. Instead of being comprised in a base station <NUM> the association module may be comprised in the control server <NUM>.

<FIG> shows an exemplifying embodiment of current switchover between three vehicle collectors 14a, 14b, 14c. The inner distance between the collectors is <NUM> and the width of the collector is <NUM>. The segments are each <NUM> long and an insulator <NUM> is arranged between the segments and is <NUM> long.

Each second segment 30b is always grounded. The intermediate segment 30a is also grounded, unless activated.

Each segment 30a of an electric road track <NUM> powered by a specific power station <NUM> is provided by the base station <NUM> with an activation key associated with an identification key of the vehicle. Thus, each segment 30a is activatable by receiving an activation request from the vehicle comprising the identification key. If no activation key is stored by the segment, it cannot be activated. If several activation keys associated with several vehicle identification keys are stored, each vehicle can activate the segment comprising the corresponding activation key.

In <FIG>, a first segment 30a has been activated and delivers electric current to a battery in the vehicle, via first collector 14c, while current is returned via collectors 14a and 14b, both being connected to a grounded segment 30b. All other segments 30a and 30b are grounded.

In <FIG>, the mid-collector 14b has passed beyond the insulator <NUM>. When the collector 14b passes up on the insulator, the current is broken via collector 14b, but taken over by the last collector 14a. Thus, no induction voltages are generated when the current via mid-connector 14b is ended, which means that substantially no sparks are generated. When the mid-collector 14b enters the conducting segment 30a, as shown in <FIG>, current is already running to the battery via first collector 14c, which again means that no sparks are generated. The current to the battery is gently divided via the two collectors 14c and 14b. The conduction of the current from the collectors to the battery is controlled by the charging system, so that the current passes in the correct direction, for example by means of switch transistors and/or diodes.

In <FIG>, the first collector 14c has passed the insulator <NUM> and entered the next segment 30b, which is grounded. When, the first collector 14c enters the insulator, the mid-collector 14b takes over the current and no sparks are formed. When the first collector 14c contacts the grounded segment after the insulator, it shares the conduction of current to ground with the last collector 14a in a gentle manner. Again, no sparks are formed.

In <FIG>, the last collector 14a has passed the insulator <NUM>, whereby the ground current is taken over by first collector 14a. When the last collector 14a receives contact with the active segment 30a, it shares the current with the mid-collector 14b, which already has contact with the active segment.

In <FIG>, the mid-connector passes an insulator <NUM>, whereby the last collector 14a takes over the current to the battery. When the mid-connector 14b passes to the grounded segment 30b, it shares the ground current with the first collector 14c.

In <FIG>, the first collector 14c passes an insulator <NUM>. The first collector 14c is associated with the short range transmitter <NUM> of the vehicle and each insulator <NUM> is provided with a receiver <NUM>, which receives the activation request and identification key from the vehicle. Upon positive confirmation, the new activatable segment 30a' is activated and switched from a grounded state to an active state. If the vehicle has a high speed, such activation may be in the position shown in <FIG>. The system is arranged so that the activation takes place before the last collector 14a has left the contact with the previous active segment 30a. Alternatively, at slow speed the active state of segment 30a' may be reached during the time the first collector 14c is passing the insulator <NUM>, which means that the segment 30a' is already active when the first collector 14c contacts the new segment 30a' or shortly thereafter. In this case, a deactivation request is sent by the new segment 30a' as soon as it is activated and as soon as current is drawn from the new segment 30a' by the first collector 14c. The deactivation request is sent to the previous segment 30a, which is deactivated and connected to ground.

In this manner, a smooth delivery of current to the battery, or electric motor, is assured. The current is continuous, which means that maximum energy is transferred during a specific time period.

Each active segment is deactivated when receiving a deactivation request, as mentioned above, or when a specific time period has elapsed determined based on the speed of the vehicle, or when the segment senses that current has been drawn from the system, but has ceased. Other criteria may be used, such as the fact that fraud on the system is detected.

As soon as a segment has been activated, the segment may be arranged to send a deactivation request to all other segments in the electric road track, except the next segment in the electric road system. This means that no other segment can be activated, except the following segment.

There may be more than three collectors arranged.

A similar action is performed when the vehicle passes from one electric road track <NUM> to the next electric road track.

The short range transmitter <NUM> of the vehicle and the receiver <NUM> may be arranged to operate by different technologies, such as radio waves, including RFID technology, or Hall-sensors detecting magnetic fields, or inductive technology, or sound or vibration based technology, or conductive pick-up, or any combination of such technologies. If radio (or sound) waves are used, Doppler effect may be used for detecting that the transmitter has passed the receiver, due to the decrease in frequency. In an embodiment, one transmitter <NUM> is arranged close to the front of the vehicle and another transmitter <NUM>' is arranged close to the end of the vehicle. A receiver <NUM> is arranged adjacent the insulator <NUM>. The signals from transmitters <NUM> and <NUM>' may be discriminated by the receiver. When the receiver determines that the signal strength from both transmitters <NUM> and <NUM>' are equal, it is an indication that the vehicle is positioned directly above the receiver. The signals from one or both transmitters may be modulated to transmit the identification key to the receiver.

The transmitter <NUM> may be arranged as a rectangular coil, the symmetry axis being substantially vertical. The coil has a distance between the coil sides which are perpendicular to the driving direction, the distance being about <NUM> - <NUM>, such as <NUM>. The receiver <NUM> comprises a coil being arranged with the symmetry axis horizontal. The system may operate at a frequency of about <NUM>. The receiver <NUM> will first sense a signal from the leading side of the transmitter coil and then a signal from the trailing side of the transmitter coil, which signals have opposite phases. The phase shift and the amplitude of the field can be used for accurately determine when the transmitter coil passes the receiver coil. The used frequency of about <NUM> is used because the disturbances in this frequency range are small. Frequency or amplitude modulation may be used for transmitting the desired information, the identification key. It is desired to transmit about <NUM> bits of data, for example three times for redundancy.

Furthermore, the vehicle communication connection may be a connection being based on light as the data carrying medium. For example, the vehicle communication connection may be embodied as modulations of an IR-light beam. Alternatively, or in combination, the vehicle communication connection may be a connection being based on sound, especially ultrasound.

Moreover, the identification message sent from the vehicle to the base station, the transmission of the identification key from the base station to the vehicle, the transmission of the activation key from the base station to the segments of the first set of segments and/or the activation request sent from the vehicle to the segment to be activated may be encrypted.

Furthermore, the identification message may additionally comprise other data pertaining to the vehicle, such as speed of the vehicle, power outtake needed for the vehicle, the type of vehicle, the position of the vehicle, or other data indicating status of the vehicle. This other data may be transmitted from the base station to the segments of the first set of segments. This provide for an efficient way of providing the segments of the first set of segments with additional data pertaining to the approaching vehicle without the vehicle being required to send this additional data directly to the segments of the first set of segments. Hence, the amount of data being transmitted from the vehicle directly to the segments of the first set of segments may be minimized. The data pertaining to the vehicle may be transferred from a base station <NUM> to the control server <NUM>.

Moreover, the segments 30a may be arranged to collect additional data, such as voltage, temperature, sound data, shake sensor data, acceleration, humidity and controller reports of errors. The segments 30a may transmit this additional data to the base station <NUM> via the segment communication connection. Further, this additional data may be transferred from a base station <NUM> to the control server <NUM>.

Claim 1:
A method for enabling electrical power delivery to vehicles during traveling, the method comprising:
receiving, at a base station (<NUM>), identification data transmitted from a vehicle, the identification data identifying the vehicle;
associating an activation key with the identification data;
transmitting the activation key from the base station (<NUM>) to a segment of a plurality of segments (30a, 30b) consecutively arranged along a single track line to provide alternating potentials, wherein every second of the plurality of segments, including the segment, belong to a first set of segments (30a) to be powered, and wherein other segments form a second set of non-powered segments (30b);
receiving, at the segment and via short range radio communication having a range of <NUM> to <NUM> meters, an activation request sent from the vehicle, wherein the activation request comprises an identification key associated with the identification data;
confirming, at the segment, that the received identification key is associated with the received activation key;
upon positive confirmation, activating the segment for enabling power delivery to the vehicle and transmitting a deactivation request from the segment to a previously activated segment of the first set of segments (30a) of the plurality of segments (30a, 30b);
powering the segment and creating a voltage difference between the powered segment and the non-powered segments to provide alternating potentials;
measuring power delivered by the powering segment while activated through a measuring module (39a) comprised therein; and
storing the measured delivered power in a database in association with the identification data.