FR3102953A1 - Ground power system and method for unguided electric vehicles - Google Patents

Abstract

Ground power system and method for unguided electric vehicles Ground power system (10) for unguided electric vehicles (1) adapted to connect a segment (11.i) of track ( 11) to a source (400)) of supply voltage only if an electric vehicle has been determined on said segment and to disconnect said segment from the voltage otherwise; said system being characterized in that it is suitable for, if an obstacle is detected: - near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and / or - to proximity to, or on a, portion of said segment located behind said vehicle located on said segment, then disconnecting said segment from the voltage source. Figure for abstract: Figure 1

Description

Ground powered system and method for unguided electric vehicles

The present invention relates to a ground power system for unguided electric vehicles.

An electric vehicle comprises a rechargeable battery and an electric motor, powered by the battery and making it possible to propel the vehicle.

For unguided electric vehicles (i.e. trucks, vans, passenger cars, etc., not constrained to travel along tracks, especially railway tracks), it is known to charge the vehicle battery when it is stationary, by connecting the battery to a charging station, using an electric cable.

It has also been proposed to recharge the battery of an unguided electric vehicle during its movement by conduction power systems.

Among conduction power systems, document FR 14 52525 discloses a road surface whose surface is provided with two grooves parallel to each other and extending longitudinally in the direction of the road. Inside each of the grooves one or more electric current supply rails circulate.

To capture the electric current, the unguided electric vehicle is equipped with a pole, the end of which is capable of penetrating into the grooves of the roadway so as to come into electrical contact with the supply rails, subdivided into longitudinal segments.

A segment is connected to a supply voltage source through a switch which is controlled according to a signal relating to the position of the vehicle to be supplied.

This position signal is for example generated during the detection, by a magnetic loop integrated into the roadway and circulating along the segment considered, of a signal generated by a transmission device placed on the vehicle, for example of a RFID type tag (for "Radio Frequency Identification" in English). Upon receipt of such a position signal, a control device closes the switch so that the segment in question is electrically connected to the voltage source, provided for example that the speed of the vehicle also verifies certain conditions. .

The segments may however be longer than the length of the unguided electric vehicles, which makes the situation dangerous when in particular pedestrians are in a position to come into contact with a segment brought to the potential of the voltage source and on which the vehicle.

The object of the invention is to provide an improved ground power system for unguided vehicles.

To this end, according to a first aspect, the invention proposes a ground power system for unguided electric vehicles, said system having a pair of power supply tracks comprising a so-called phase conductive track adapted to be brought to a supply voltage, and a so-called neutral conductive track for the return of the current, the phase track being made up of a plurality of segments n° i, i = 1 to N, arranged end to end, each segment being insulated electrically from its neighbors, in which the system comprises:

a voltage source capable of delivering a supply voltage;

a presence detection block to determine whether an unguided electric vehicle is present on or in the immediate vicinity of a segment or not;

a control block for selectively connecting a segment to the voltage source, selectively disconnecting said segment from the voltage source, said control block being adapted to only connect a segment to the voltage source if an unguided electric vehicle has been determined in close proximity to said segment or on said segment and to disconnect said segment from the voltage source if no unguided electric vehicle has been determined in close proximity to said segment or on said segment;

said system being characterized in that the control unit is suitable for, if an obstacle is detected:

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment or in the immediate vicinity of said segment, and/or

- near or on a portion of said segment located behind said vehicle located on said segment,

then disconnecting said segment from the voltage source.

The invention thus makes it possible to increase the safety of ground power systems for unguided electric vehicles.

In embodiments, the underfloor power system for unguided electric vehicles of the invention further includes one or more of the following features:

- a set of obstacle detector(s) is on board the unguided electric vehicle and comprises a sensor located at the front of said vehicle and/or a sensor located at the rear of said vehicle, said set being adapted to detect whether an obstacle is present on a portion of a segment within a sensor capture area based on data captured by the sensor;

- the unguided electric vehicle comprises a wireless telecommunications transmitter block adapted to emit a first presence signal, and in which the presence detection block is adapted to determine whether an unguided electric vehicle is present or in the immediate vicinity of a segment as a function of a second presence signal induced by said first presence signal in an antenna forming a loop around said segment;

- said system being suitable for, in the event of detection of an obstacle:

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment or in the immediate vicinity of said segment, and/or

- near, or on, a portion of said segment located behind said vehicle located on said segment,

controlling the cessation of transmission of said first presence signal;

- the power supply system is suitable for the detection of an obstacle:

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment or in the immediate vicinity of said segment, and/or

- near or on a portion of said segment located behind said vehicle located on said segment;

command a switch to a vehicle power mode other than via said segment;

- the control unit is suitable for, if an obstacle is detected:

- near or on a portion of a segment located in front of an unguided electric vehicle located on said segment or in the immediate vicinity of said segment, and/or

- near or on a portion of said segment located behind said vehicle located on said segment,

then disconnecting said segment from the voltage source for a timeout period, then reconnecting said segment from the voltage source at the end of said period;

- the power supply system is adapted to determine the delay time according to the type of obstacle currently present on said segment portion.

According to a second aspect, the present invention provides a ground power method for unguided electric vehicles in a ground power system having a pair of power tracks comprising a so-called phase conductive track brought to a supply voltage, and a so-called neutral conductive track for the return of the current, the phase track being made up of a plurality of segments n° i, i = 1 to N, arranged end to end, each segment being electrically insulated of its neighbors, whereby the following steps are implemented:

• determination, by an electronic presence detection unit, of whether an unguided electric vehicle is present on or in the immediate vicinity of a segment or not;
• by a control block, selectively implementing a connection of a segment to a voltage source delivering a supply voltage only if an unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment, and a disconnection of said segment from the voltage source if no unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment;

said method being characterized in that it comprises the following step implemented by the control block:

if an obstacle is detected:

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or

- near, or on a portion of said segment located behind said vehicle located on said segment,

then disconnecting said segment from the voltage source.

In embodiments, the method according to the invention further comprises one or more of the following features:

- a set of obstacle detector(s) is on board the unguided electric vehicle and comprises a sensor located at the front of said vehicle and/or a sensor located at the rear of said vehicle, said set detecting whether an obstacle is present on a portion of a segment within a sensor capture area based on data captured by the sensor;

- it includes the following steps

- emission by a wireless telecommunications transmitter unit on board the unguided electric vehicle of a first presence signal, and determination by the presence detection unit that an unguided electric vehicle is present or in the immediate vicinity of a segment as a function of a second presence signal induced by said first presence signal in an antenna forming a loop around said segment;

- control of the stopping of the emission of said first presence signal in the event of detection of an obstacle:

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or

- near or on a portion of a segment located behind said vehicle located on said segment;

- it includes a step for controlling a changeover to a vehicle power supply mode other than via said segment, in the event of the detection of an obstacle

- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or

- near or on a portion of a segment located behind said vehicle located on said segment.

The characteristics and advantages of the invention will appear on reading the following description, given solely by way of example, and made with reference to the appended drawings, in which:

FIG. 1 is a view schematically representing an unguided electric vehicle traveling on a roadway equipped with the underfloor supply system in one embodiment of the invention;

FIG. 2 is another view, with block diagrams, of the pavement of FIG. 1 equipped with the ground supply system in one embodiment of the invention;

Figure 3 illustrates a traffic situation on the roadway of Figure 1;

Figure 4 illustrates another traffic situation on the roadway of Figure 1;

Figure 5 is a schematic representation of a method of using the system of Figure 1.

Figures 1 and 2 represent an unguided electric vehicle 1, for example a truck 1, traveling on a roadway 2. Obviously, different types of unguided vehicles will be required to travel on the roadway 2 using the power supply system by floor. Thus, the term unguided electric vehicle includes freight trucks, passenger coaches, passenger cars, etc.

A trihedron XYZ is associated in a classic way with the truck 1: the axis X according to the longitudinal direction, directed towards the front; the Y axis in the transverse direction, oriented from left to right; and the Z axis in the vertical direction, oriented from bottom to top.

The truck 1 comprises a body and wheels, some of which are steering and steering means (not shown) allowing a driver to modify the angle of the steering wheels in the XY plane so as to steer the vehicle 1.

Truck 1 includes a rechargeable battery and an electric motor (not shown). In traction, these main electrical means require a power of around 150 kW.

The truck 1 is equipped with a capture means making it possible to collect electrical power during the movement of the truck 1. The capture means are generally referenced by the number 5 in Figures 1 and 2.

The capture means 5 comprises a pad capable of being brought into sliding contact on a pair of feed tracks of the ground feed system.

The electric truck 1 comprises one or more obstacle sensors, here a rear sensor 2 and a front sensor 3.

The electric truck 1 further comprises an electronic control unit 20, which comprises an electronic processing block 7, an electronic block 9 for controlling the skid and a transmitter block 4.

The electric truck 1 further comprises an electronic block 110 for energy management.

Each of the obstacle sensors 2, respectively 3, is suitable for detecting the presence of an obstacle in a detection zone associated with them, respectively Z2, Z1.

In one embodiment, the obstacle sensors 2, 3 comprise a video sensor (and/or an ultrasound sensor and/or a radar sensor and/or a lidar sensor and a processing unit adapted to perform processing on the data acquired by the video sensor, representative of the possible occupation by obstacles of the associated detection zone.The processings are for example algorithmic processings to identify from these data the presence of obstacles in the associated zone. giving rise to identification are for example of the type people, animals, two-wheelers.In one embodiment, the processing operations are further adapted to classify an obstacle identified in a category among several possible categories: pedestrians, animals, two-wheelers, etc.

The obstacle sensors 2, 3 are adapted to, as soon as they identify an obstacle in the zones Z1, Z2, deliver to the processing unit 7 an alert indicating that an obstacle has been identified (and if necessary its category) .

The processing block 7 is suitable for, upon receipt of an alert indicating an obstacle identified in the zone Z1 or Z2 coming from one of the obstacle sensors 2, 3, commanding the transmitter block 4 to stop the emission of the radio signal intended to make known the presence of the vehicle on a particular segment.

The energy management block 110 is adapted to obtain electrical energy selectively, from the segments of the supply track 11 or from other means, for example an on-board battery, a thermal source (in such case the engine is for example switched to a heat engine), then supply this electrical energy to the on-board equipment (engine, air conditioning, ventilation, battery, etc.); the selection is made for example according to commands which are sent to it, for example by the processing block 7 or by an on-board vehicle computer or on automatic detection of the loss of voltage on the ground power supply, .

The transmitter block 4 is arranged in whole or in part at the level of the pad 5 in one embodiment of the invention. This transmitter block 4 is suitable for transmitting, continuously, unless otherwise ordered by the processing block 7, a radio signal having for example a characteristic frequency of 500 kHz. Upon receipt of a stop transmission command from the processing block 7, the transmitter block 4 is adapted to stop the transmission of the radio signal.

This stoppage is maintained as long as the transmitter block 4 has not received a transmission resumption command from the processing block 7, which is adapted to send such a command at the end of a predetermined time delay T after the command. stopping (the duration of this time delay T is for example included in the range [5s, 60s]) or in another embodiment, as soon as there is no longer any obstacle detection alert transmitted by an obstacle sensor 2, 3 .

The roadway 2, represented schematically in Figures 1, 2 according to different viewing angles, comprises in a known manner a trench inside which is positioned the ground supply track, generally referenced by the number 10.

In position, the supply track 10 comprises, flush with the surface of the roadway 2:

- a phase conductor track 11, electrically connected either to an electric power source or to the reference potential, as will be described below;

- a conductive neutral track 12, electrically connected to the current return of the vehicle or to a reference potential Vref, for example 0 V;

- a conductive protection track 13, electrically connected to the current return of the vehicle or to a reference potential Vref, for example 0 V.

More precisely, the tracks 11 and 12 project slightly above the surface of the roadway 2, for example by a height of the order of a few millimeters, in particular equal to 2 mm. Runway 13 is at surface level 8 of carriageway 2.

The phase track 11 consists of a plurality of metallic segments (referenced 11.i in FIGS. 1 to 4, i=1 to N, with N for example included in a range [45;90]) which, in a embodiment, each have for example a width of 5 cm and a length of 11 m. The segments are therefore longer than at least some of the unguided electric vehicles that they power: generally during the circulation of a vehicle 1, there is a portion of the segment on which the vehicle is located, which extends in front of the vehicle and/or a portion of the segment which extends behind the vehicle.

The segments are arranged end to end to form the phase track 11.

The segments are electrically isolated from each other.

Advantageously, the neutral track 12 is made using segments of the same type as those used for the phase track 11. Thus, the track 12 consists of a plurality of segments having a width of approximately 5 cm and a length about 11 m.

The insulation between the consecutive segments of the neutral track 12 is here of the same nature as that of the phase track 11. However, although segmentation is necessary for mechanical reasons (dilation), the dielectric strength level between segments is not necessarily as high as that between segments of phase track 11.

The neutral track 12 runs parallel to the phase track 11, on a first side of the latter. The lateral edge of the phase track 11 and the lateral edge of the neutral track 12, which face each other, are spaced apart by a first distance of approximately 15 cm.

The protection track 13 is made up of a plurality of interconnected metal segments.

The protection track 13 is arranged parallel to the phase track 11, on a second side of the latter opposite to the first side of the phase track 11 comprising the neutral track 12.

The lateral edge of the phase track 11 and the lateral edge of the protection track 13, which face each other, are spaced apart by a second distance of approximately 15 cm.

The function of the protection track 13 is to constitute, on the second side, a means of collecting the electrons of a leakage current coming from the phase conductor track 11.

Current leakage to the first side is collected by neutral track 12.

In the embodiment envisaged, the width of the protective track 13 is approximately 1 cm.

With this particular choice of values for the transverse dimensions of the various tracks and their mutual spacing, the part present on the ground, as presented above, of the ground supply system 10 has a total width on the roadway of about 50cm. This total width is chosen to remain less than the center distance of the smallest unguided electric vehicle likely to travel on roadway 2 and use system 10.

When the phase track 11 is connected to the power source, any current leakage, due for example to the presence of a puddle or a film of water on the surface of the roadway, is collected on the first side by the neutral track 12 and on the second side by the protection track 13. This prevents the portion of the road surface brought to such a high potential from extending laterally beyond the width of the system of floor supply 10. By choosing the total width of the floor supply system 10 less than the center distance of the smallest vehicle authorized to circulate on the roadway 2 and able to use the system 10, it is guaranteed that if a pedestrian is laterally on the first or second side of a segment of the phase track 11, but beyond either the neutral track 12 or the guard track 13, the pedestrian will not be electrocuted if this segment is raised to high potential.

To facilitate the installation of the system 10, the latter comprises a support assembly for the various tracks described for example in the application FR 14 52525.

The detection zone Z1 associated with the front obstacle sensor 3 comprises, in one embodiment, the portion of a segment 11.i located at the front of the truck 1 and not covered by the vehicle 1 when it is located on segment 11.i. The detection zone Z1 associated with the front obstacle sensor 3 comprises, in one embodiment, at least a portion of a segment 11.i located at the front of the vehicle and not covered by the vehicle 1 when the latter is located on segment 11.i.

Similarly, the detection zone Z2 associated with the rear obstacle sensor 2 comprises, in one embodiment, the (or at least one) portion of a segment 11.i located at the rear of the truck 1 and not covered by the vehicle 1 when the latter is located on segment 11.i

These arrangements are obtained by choosing the location for mounting the sensors 2, 3 on the truck 1 and adjusting the detection parameters of the sensors 2, 3. Each segment 11.i of the plurality of segments is electrically connected, via a feeder cable 15.i and a dedicated electronic control unit 31.i, alternatively either to a supply line 30.i connected to a source of electric power 400, or to the potential of the current return.

The control unit 31.i comprises an electronic presence detection block 520.i, an electronic speed determination block 521.i, an electronic control block 522.i and a switch block 523.i.

In one embodiment, the length of the detection zones Z1, Z2 is calculated as a function of the maximum speed of the vehicle powered by the ground (for example 90 km/h), and advantageously of the cumulative detection and analysis times of the obstacles by the sensors and/or processing by the processing block 7 and/or stop T of the emission and/or cut-off of the power supply by the ground by the control unit 31.i and the width of the detection zones Z1, Z2 correspond to that of the traffic lane on which vehicle 1 is traveling.

The electrical power source 400 is suitable for delivering a supply voltage V _S, for example 750 V DC. For example, the source 400 is an electrical substation converting a high voltage alternating current into a low voltage direct current (750V DC).

In a known manner, an antenna 52.i, called the detection antenna, is arranged at the level of each segment 11.i. The detection antenna 52.i circulates in the roadway 2, to form a loop, called detection loop, around the segment 11.i (exclusively around the segment 11.i, i.e. without encompassing part of the segments which are adjacent to it ), so as to detect the presence of a vehicle above the segment 11.i. More specifically, it circulates in longitudinal channels provided in each of the side edges of the phase track support profile.

Each antenna 52.i is capable of picking up the signal emitted by the transmitter unit 4, when the shoe 5 passes close by, for example less than approximately 15 cm from the antenna 52.i, and of generating a corresponding induced signal. The corresponding signal generated within the detection antenna 52.i is applied via an antenna cable 16.i at the input of the presence detection block 520.i of the control unit 31.i.

The signal s generated by the antenna 52.i corresponds to the signal emitted by the transmitter unit 4 of the vehicle 1, convoluted with a function corresponding to the shape of the antenna and to the instantaneous speed of the vehicle. In the present case, the signal s comprises a rising edge corresponding to the arrival of the vehicle within 15 cm of the antenna, a plateau as long as the vehicle is still above the antenna, then a falling edge indicating let him get away.

The presence detection block 520.i is suitable for determining at any time whether or not a vehicle is present above the segment 11.i, depending on the current signal provided by the detection antenna 52.i. The presence detection block 520.i is adapted to transmit to the control block 522.i information (PRES) indicating the presence of a signal in the antenna 52.i as induced by the signal emitted by the block transmitter 4, and indicating information (NOT NEAR) indicating the absence of such a signal in the antenna 52.i, as soon as it detects it.

The speed determination block 521.i is suitable for determining the speed V of a vehicle 1 located on the segment 11.i: different methods can be implemented to do this, using or not the signal emitted by the transmitter block 4, for example using a speed antenna loop located at segment 11.i-1 or another type of speed sensor.

The control block 522.i is adapted to verify a set of conditions and to, depending on these conditions, control the switch block 523.i to connect the segment 11.i selectively either to the electric power source 30 at the voltage V _s , that is to the current return.

Among these conditions, it is suitable for checking that a speed V transmitted by the speed determination block 521.i is well within an authorized range of values, ie well between a predetermined value V ₁ and a predetermined value V ₂ , with V ₁ <V ₂ , for example V ₁ equal to 30 km/hour, and V ₂ = 90 km/hour.

The command block 522.i is also suitable for, as soon as it receives information of the PRES type from the presence detection block 520.i (thus indicating, given the above, the presence of a vehicle 1 on segment 11.i combined with the absence of identified obstacles) and after having checked that the current speed V of the vehicle is indeed between V ₁ and V ₂ , control the switch block 523.i so as to connect the segment 11 .i to the electrical power source 400 and inform the energy management unit 110 of said connection.

The command block 522.i is also suitable for, as soon as it receives information of the NOT NEAR type from the presence detection block 520.i (indicating that no vehicle is present on the segment 11.i or when an obstacle has been detected by the sensors 2, 3 of a vehicle present on the segment 11.i), order the switch block 523.i to connect the segment 11.i to the current return and thus inform the block of energy management 110 of disconnection.

In one embodiment, the control unit 31.i comprises a memory and a processor. Said memory comprises software instructions which, when executed by the processor, implement at least some of the steps of the set 100 of steps indicated below with reference to FIG. 5. Thus, in such a mode of embodiment, the electronic presence detection block 520.i, the electronic speed determination block 521.i and/or the electronic control block 522.i comprise software bricks.

All the switch blocks 523.i, i=1 to N, of roadway 2 are controlled by default so that the segments 11.i are connected to the non-dangerous potential of the traction current return, and this as long as no vehicle is not detected on any of these segments.

Let us consider that a vehicle 1, for example truck 1, moves in the direction of increasing i on roadway 2 and that it then arrives on segment 11.i.

In a step 101, the following operations take place.

Obstacle sensors 2 and 3 of vehicle 1 monitor zones Z1 and Z2 and check that no obstacle arises in these zones. The transmitter block 4 of the vehicle 1 transmits its continuous signal. The detection antenna 52.i at the level of the segment 11.i generates a signal s under the effect of the proximity of the transmitter block 4 of the truck 1. The presence detection block 520.i, depending on the signal s received , transmits information PRES to the command block 522.i. The speed determination block 521.i determines the value V of the speed of vehicle 1. The value of the determined speed V is transmitted to the control block 522.i by the speed determination block 521.i.

The command block 522.i then checks that the value of the speed V is indeed between V ₁ and V ₂ . In the positive case, and given that PRES information has been received (which means that no obstacle has been signaled as currently present on the segment 11.i by the obstacle sensors 2 and 3 and that the vehicle 1 is located on segment 11.i), switch block 523.i is controlled by control block 522.i to connect segment 11.i to electrical power source 400 at voltage V _s , thus bringing the segment 11.i at the supply voltage V _S .. The collection means 5 of the truck 1, rubbing simultaneously on the phase 11 and neutral 12 tracks, picks up the supply current and sends the return current traction .

The energy management block 110 then controls the supply of the on-board elements by distributing this captured supply current.

It will be noted that if one of these conditions had not been fulfilled, the switch block 523.i would have remained controlled so as to connect the segment 11.i to the traction current return potential.

Consider that an obstacle then arises in zone Z1 or Z2. In a step 102, the sensor 2 or 3 associated with the zone in which the obstacle has arisen detects this obstacle (and determines its category if applicable), then delivers an alert indicating that an obstacle has been identified (and the case its category) to the processing block 7, which then controls the stopping of the transmission of the radio signal by the transmitter block 4.

The detection antenna 52.i at the level of the segment 11.i then no longer generates signal s under the effect of the proximity of the transmitter unit 4 of the truck 1 since the latter no longer transmits. The presence detection block 520.i consequently transmits information NON PRES to the control block 522.i, which then controls the switch block 523.i to disconnect the segment from the voltage source V _s and to connect the segment 11 .i at ground potential. The command block 522.i informs the energy management block 110 of said disconnection. The energy management block 110 controls for example the supply of power by an on-board AC system, for example a battery system and controls the power supply of the on-board elements according to this system. In one embodiment, it can also control the pad control unit 9 to raise the pad if necessary (which must then be lowered as soon as the segment on which the vehicle 1 is located is again supplied by V _s ).

In a step 103, which begins at the end of a predetermined time delay T (or else in another embodiment, which begins as soon as the obstacle detection alert disappears, the processing block 7 re-authorizes the transmission by the transmitter block 4), the transmitter block 4 proceeds again to the transmission of its signal and as indicated in step 101, subject to a current speed value present in the authorized range and the presence of the vehicle 1 on the segment 11.i, the latter is resupplied with the voltage V _s following the switching command of the switch block 523.i by the control block 522.i.

In one embodiment, the obstacle presence alert and its category are transmitted by the processing block 7, for example by radio communication, to a remote control station.

Thus as the vehicle 1 moves, as long as there are no obstacles and the speed complies with the authorized range, the various segments of the phase track 11 are thus successively activated in synchronization with the movement of the car 1 along the roadway 2. It should be noted that the segments 11.i are supplied successively, so that a single segment or possibly two segments are at the potential of 750 V at a given instant .

As indicated above, the potential to which the segments are carried is selected as a function of the speed of vehicle 1 and its position. If an obstacle is detected in one of the zones Z1, Z2, the supply voltage to a segment on which the vehicle 1 is located is stopped.

The presence of the vehicle on a segment is constantly monitored and the powering of a segment is terminated as soon as an absence of a vehicle on the segment is detected.

If the unguided electric vehicle 1 is caught in a traffic jam and is traveling at low speed (speed lower than V ₁ ) or traveling too quickly (speed higher than V ₂ ), the electrical potential to which the segment of the phase track 11 is brought on which it is located is zero, with no risk for a pedestrian of being electrocuted.

If the unguided electric vehicle 1 normally travels at a speed between V ₁ and V ₂ and which is associated with the section of the roadway on which the vehicle 1 is engaged, the electrical potential to which the segment of the phase track is brought on which the unguided electric vehicle is located is high and corresponds to the supply voltage V _S . This high electrical potential makes it possible to transfer significant power to the unguided electric vehicle, compatible with the operation of its main electrical means. As soon as an obstacle presenting a risk is detected, the segment is brought back to zero potential.

In a variant, the zero potential is replaced by a low potential, i.e. presenting no risk of electrocution, typically less than 60V.

FIG. 3 illustrates a traffic situation on the roadway of FIG. 1 with a supply system according to the invention: truck 1 travels on segment 11.i at an authorized speed, other vehicles 44 and 45 travel in a traffic lane parallel to that of the truck 1 and no obstacle appears in the zones Z1, Z2: the segment 11.i is therefore supplied with the voltage V _s (the portions of the segment 11.i thus supplied located in front and behind the truck 1 are shown hatched).

FIG. 4 illustrates another traffic situation on the roadway of FIG. 1 with a supply system according to the invention: truck 1 travels on segment 11.i at an authorized speed, other vehicles 47 and 49 travel at proximity of truck 1, as well as pedestrians 48, 46. Pedestrian 48 being detected as an obstacle in zone Z2, segment 11.i is not supplied with voltage V _s .

In one embodiment, the front sensor 3 (and/or in one embodiment the rear sensor 2) also monitors a zone Z beyond the zone associated with it, here Z1, covering the parallel tracks in front of the truck 1 and identifies as the only obstacles giving rise to an alert a subset of the categories, for example only pedestrians. In such a case, with reference to FIG. 4, the pedestrians 46 would also have been detected as obstacles giving rise to the interruption of the power supply V _s .

In another embodiment, the electronic speed determination block 521.i and/or the electronic control block 522.i is produced in the form of a programmable logic component, such as an FPGA (from English Field Programmable Gate Array ), or even in the form of a dedicated integrated circuit, such as an ASIC (from English Applications Specific Integrated Circuit ).

Many variant embodiments of the method of using the floor supply system are possible. In some embodiments, the underfloor supply system comprises, instead of or in addition to the on-board sensors, a set of obstacle detectors outside the vehicle, for example based on a system of cameras arranged along the roads , to detect if an obstacle is present on a segment.

In the current embodiment, as soon as an obstacle is identified, the transmission of the presence signal is stopped by the on-board transmitter unit. In another alternative embodiment, the information on the presence of obstacles does not cause the transmission to be stopped by the on-board transmitter block, but instead is supplied, for example, by wireless telecommunication to the control unit 31.i. And the latter then controls the switch block 523.i so as to connect the segment 11.i to the electric power source 400 that if both V is in the required range, the PRES information is received and no presence information obstacles is received by the control unit 31.i.

In the embodiment described above, the presence detection block 520.i detects whether an unguided electric vehicle 1 is present on a segment.

In another embodiment, it detects whether or not an unguided electric vehicle 1 is present on a segment or in close proximity to a segment or not (e.g., "in close proximity" means within a distance of less than 3 meters of the segment, preferably less than 1 m, preferably of the order of ten cm, depending on the direction of traffic on the lane, i.e. the vehicle is heading towards the segment and is at a distance of less than 3 meters from the segment, preferably less than 1 m, preferably of the order of ten cm), said segment then being disconnected from the voltage source when no unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment, the segment then being connected in the event of vehicle detection provided that no obstacle is detected.

And in one embodiment, the control unit is suitable for, as soon as an obstacle is detected close to - or on - a portion of a segment located in front of an unguided electric vehicle located on said segment, and/ or close to - or on - a portion of said segment located behind said vehicle located on said segment, then disconnecting said segment from the voltage source.

The meaning of the expression “nearby” depends here on the length of the detection zone of the sensors 2, 3 which depends on the maximum speed of the vehicle powered by the ground (90 km/h), and advantageously on the cumulative detection times and analysis of obstacles by the sensors. Advantageously, in one embodiment, "nearby" means at a distance of less than 11 meters, preferably less than 3 meters, while the length of the detection zone is for example less than 21 m, preferably less than 14 meters .

Claims (10)

An underfloor power system (10) for unguided electric vehicles (1), said system having a pair of power tracks comprising a so-called phase conductor track (11) adapted to be brought to a supply voltage , and a so-called neutral conductive track (12) for the return of the current, the phase track being made up of a plurality of segments (11.i) n° i, i = 1 to N, arranged end to end, each segment being electrically isolated from its neighbors, in which the system comprises:
a voltage source (400) capable of delivering a supply voltage (V _S );
a presence detection block (520.i) for determining whether an unguided electric vehicle (1) is present on or in the immediate vicinity of a segment or not;
a control block (31.i) for selectively connecting a segment to the voltage source, selectively disconnecting said segment from the voltage source, said control block being adapted to connect a segment to the voltage source only if a vehicle unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment and for disconnecting said segment from the voltage source if no unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment;
said system being characterized in that the control unit is suitable for, if an obstacle is detected:
- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- near, or on, a portion of a segment located behind said vehicle located on said segment,
then disconnecting said segment from the voltage source. Power supply system according to claim 1, comprising a set of obstacle detector(s) on board the unguided electric vehicle (1) and comprising a sensor located at the front of said vehicle (1) and/or a sensor located at the rear of said vehicle, said assembly being suitable for detecting whether an obstacle is present on a portion of a segment appearing in a capture zone of the sensor as a function of the data captured by the sensor. A power system according to claim 1 or 2, wherein the unguided electric vehicle (1) comprises a wireless telecommunications transmitter unit adapted to transmit a first presence signal, and wherein the presence detection unit (52. i) is adapted to determine whether an unguided electric vehicle (1) is present on or in the immediate vicinity of a segment according to a second presence signal induced by said first presence signal in an antenna forming a loop around said segment;
said system being suitable for, in the event of detection of an obstacle:
- close to, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- near, or on, a portion of a segment located behind said vehicle located on said segment,
controlling the stopping of the transmission of said first presence signal. Supply system according to any one of the preceding claims, adapted for, in the event of detection of an obstacle:
- close to, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- near or on a portion of a segment located behind said vehicle located on said segment,
order a changeover to a power supply mode of the vehicle other than via said segment. A power system according to any preceding claim, wherein the control block is adapted to, if an obstacle is detected:
- near or on a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- near, or on, a portion of a segment located behind said vehicle located on said segment,
then disconnecting said segment from the voltage source for a delay period, then reconnecting said segment from the voltage source at the end of said period. Power supply system according to claim 5, adapted to determine the delay time according to the type of obstacle currently present on said segment portion. A ground power method for unguided electric vehicles (1), in a ground power system (10) having a pair of power tracks comprising a so-called phase conductive track (11) brought to a supply voltage, and a so-called neutral conductive track (12) for the return of the current, the phase track being made up of a plurality of segments (11.i) n° i, i = 1 to N, arranged end end, each segment being electrically isolated from its neighbors, according to which the following steps are implemented:
determination, by an electronic presence detection unit (520.i), of whether an unguided electric vehicle (1) is present on or in the immediate vicinity of a segment or not;
selective implementation, by a control unit (31.i), of a connection of a segment to a voltage source (400) delivering a supply voltage (V _s ) only if an unguided electric vehicle has has been determined in the immediate vicinity of said segment or on said segment, and a disconnection of said segment from the voltage source if no unguided electric vehicle has been determined in the immediate vicinity of said segment or on said segment;
said method being characterized in that it comprises the following step implemented by the command block:
if an obstacle is detected:
- close to, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- close to, or on a, portion of a segment located behind said vehicle located on said segment,
then disconnecting said segment from the voltage source. Supply method according to claim 7, according to which a set of obstacle detector(s) is on board the unguided electric vehicle (1) and comprises a sensor located at the front of said vehicle (1) and/or a sensor located at the rear of said vehicle, said assembly detecting whether an obstacle is present on a segment portion appearing in a capture zone of the sensor as a function of the data captured by the sensor. Feeding method according to claim 7 or 8, comprising the following steps:
- emission by a wireless telecommunications transmitter unit on board the unguided electric vehicle (1) of a first presence signal, and determination by the presence detection unit (52.i) that an unguided electric vehicle ( 1) is present or in the immediate vicinity of a segment depending on a second presence signal induced by said first presence signal in an antenna forming a loop around said segment;
- control of the stopping of the emission of said first presence signal in the event of detection of an obstacle:
- near, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- close to, or on, a portion of a segment located behind said vehicle located on said segment. Supply method according to any one of Claims 7 to 9, comprising a step of controlling a changeover to a supply mode of the vehicle other than via said segment, in the event of detection of an obstacle
- close to, or on, a portion of a segment located in front of an unguided electric vehicle located on said segment, and/or
- near or on a portion of a segment located behind said vehicle located on said segment.