Induction or conduction charging device for an electric vehicle and charging method employing such a device

Abstract

The invention relates to a charging device (10) for an electric vehicle (V) by induction or conduction, the device comprising a fixed base (40), a motorized robot (20) capable of movement, and a charging cable (30) connecting the robot (20) to the base (40), the charging cable (30) comprising an outer sheath enclosing wires, the charging device (10) further comprising a means for heating the cable. Figure 1

Description

Title of the invention: DEVICE FOR CHARGING AN ELECTRIC VEHICLE BY INDUCTION OR CONDUCTION AND CHARGING METHOD USING SUCH A DEVICE

[0001] The invention relates to a device for recharging an electric vehicle by induction or conduction, the device comprising a mobile robot connected by a recharging cable to a stationary base.

[0002] Induction charging of an electric vehicle by means of a mobile robot is known in particular from application FR2211958.

[0003] In order to avoid having to equip the robot with a large battery, a remote-controlled robot is also known from the prior art, permanently connected by a charging cable to a stationary base.

[0004] The robot moving towards a target vehicle that it must recharge may, on its journey, encounter obstacles whether this journey is indoors, for example in a garage, or outdoors on more uneven terrain. The obstacles can be of different types: bumpy terrain, a tree, snow or a pole. The charging cable pulled along the ground may get stuck, under a stone, or remain stuck in a frozen puddle.

[0005] An objective of the present invention is to remedy the defects of the prior art by proposing an improved induction or conduction charging device for an electric vehicle.

[0006] To achieve this objective, the invention proposes a device for recharging by induction or conduction of an electric vehicle, the device comprising a fixed base, a motorized robot capable of moving and a charging cable connecting the robot to the base, the charging cable comprising an outer sheath enveloping wires, in particular power wires transmitting the electrical or control power, the charging device further comprising a means for heating the cable.

[0007] The heating means makes it possible to melt recently formed snow or ice which might jam the cable.

[0008] Preferably, the heating means of the cable is a heating wire arranged inside the sheath of the charging cable, in parallel with the wires.

[0009] This allows for easy implementation and ensures heating along the entire length of the cable.

[0010] Preferably, the charging device further comprises a cable organizer, a cable release means, a temperature sensor and an electronic controller. able to control the unblocking means.

[0011] Preferably, the outer sheath of the cable has roughness.

[0012] The roughness reduces the contact surface between the ground and the cable and makes it easier to handle and store the cable.

[0013] The invention also relates to a recharging method implemented during the recharging of an electric vehicle by an induction or conduction recharging device according to the invention, the induction or conduction recharging device further comprising a force sensor capable of measuring a force necessary to unwind or store the recharging cable, the recharging method comprising a sub-method for unjamming the recharging cable, the unjamming sub-method comprising a step of measuring the force necessary to unwind or store the recharging cable, a step during which the force is compared to a limit force, if said force is strictly greater than said limit force then a step of unjamming the cable is implemented,step during which a curative strategy for unjamming the cable is carried out, comprising a step of generating successive jolts in the cable by traction or by shaking in the direction transverse to the direction of said cable.

[0014] Preferably, the sub-method implements a preventive anti-jamming strategy comprising a step of measuring ambient temperature and a step of heating the charging cable.

[0015] The invention will be further detailed by the description of non-limiting embodiments and, on the basis of the appended figures illustrating variants of the invention, in which:

[0016] [Fig.lA] schematically illustrates a recharging device according to the invention, the device comprising a robot connected by a recharging cable to a stationary base;

[0017] [Fig.lB] schematically illustrates the recharging device of [Fig.lA] and further schematically shows an electronic controller and sensors;

[0018] [Fig.2] schematically illustrates, in top view, the recharging device of the [Fig.lA], and several vehicles to be recharged. The robot moves from one to the other;

[0019] [Fig.3A] schematically illustrates a first alternative of the recharging device of [Fig.1A] and the path that the robot must follow from its base to reach its objective.

[0020] [Fig.3B] is similar to [Fig.3A], the robot having reached its objective;

[0021] [Fig.3C] is similar to Figures 3A and 3B, with the robot returning to its base while a obstacle prevents him from progressing;

[0022] [Fig.3D] schematically illustrates in a Cartesian diagram an evolution of the force necessary to store the charging cable in the event of the cable being blocked by an obstacle and the jolts given to release the cable;

[0023] [Fig.4A] schematically illustrates a second alternative of the recharging device of [Fig.1A] and the path that the robot must take from its base to reach its objective;

[0024] [Fig.4B] is similar to [Fig.4A], an obstacle preventing the robot from advancing towards its objective;

[0025] [Fig.4C] is similar to Figures 4A and 4B, the obstacle of [Fig.4B] having been overcome and the robot having reached its objective;

[0026] [Fig.4D] is similar to Figures 4A, 4B and 4C, the robot returning to its base, a new obstacle preventing it from progressing;

[0027] [Fig.4E] schematically illustrates two curative strategies for unjamming the cable;

[0028] [Fig.4F] schematically illustrates a third curative strategy for unjamming the cable;

[0029] [Fig.5A] schematically illustrates the sections of four alternatives of the charging cable;

[0030] [Fig.5B] schematically illustrates in three-dimensional representation two alternatives of the charging cable;

[0031] [Fig.6] schematically illustrates a block diagram of the electrical recharging process.

[0032] [Fig. 1A] represents a device 10 for inductively recharging an electric or rechargeable hybrid vehicle V. The device 10 comprises a mobile motorized robot 20, represented under the vehicle V, connected by a recharging cable 30 to a stationary base 40.

[0033] [Fig.lB] shows the main components of the charging device 10 and schematically adds the representation of a cable organizer 50, an electronic controller 80 connected to the robot 20, a force sensor 70 and a temperature sensor 140. The cable organizer 50 can, depending on the alternative chosen, be fixed to the robot 20 or to the base 40. The force sensor 70 is connected to the cable organizer 50. The temperature sensor 140 is fixed to the robot 20 and the electronic controller 80 can be fixed to the base 40 or to the robot 20.

[0034] The charging robot 20 comprises a motor and wheels, or any other means (tracks, air cushions, etc.) allowing it to move and an electronic induction charging circuit which cooperates with the charging circuit of the vehicle V.

[0035] The charging device 10 is intended to be used both indoors and outdoors. The motorized robot 20 is intended to move on bumpy terrain and the charging cable 30 is sufficiently flexible to conform to the unevenness (O) of the terrain.

[0036] [Fig. 2] schematically represents in top view the charging device 10 which has to move between several vehicles V to be recharged. The charging cable 30 is sufficiently long so that the robot 20 has a range of action allowing it to move between several vehicles V. move between all vehicles V.

[0037] The recharging device 10 further comprises the cable organizer 50 which stores the cable so that it does not drag on the ground unnecessarily, for example when the robot 20 is at its base 40 or is moving between two vehicles V, one being close to the base 40 and the other further away.

[0038] A cable reel is a known technology for storing a cable. Any other technology for delivering cable or, on the contrary, storing it can also be used. In [Fig. 2], the cable organizer 50 is attached to the robot 20 but, it can also be attached to the base 40.

[0039] The recharging device 10 further comprises a guidance system 60 of the robot 20, the force sensor 70 measuring the force F necessary to deliver or store the cable and the temperature sensor 140 fixed to the robot 20, the temperature sensor 140 measuring the ambient temperature around the robot 20. The guidance system 60 and the sensors (forces 70 and temperature 140) are connected to the electronic controller 80 which can be fixed to the robot 20 or to the base 40.

[0040] The guidance system 60 guides the robot in its journeys towards a vehicle V to be recharged or between two vehicles, and in its “return” journeys towards the base 40. The guidance system 60 can comprise a camera, a map of the area of ​​action of the robot 20 which can be memorized, ultrasound transmitters and receivers, terrain sensory sensors which permanently inform the electronic controller 80. Other guidance systems exist.

[0041] Figures 3A, 3B and 3C show, in the same environment, a first alternative of the recharging device 10 in which the cable organizer 50 is fixed to the robot 20.

[0042] In this environment, two obstacles O are located between the base 40 and the vehicle V that the robot 20 must recharge. These obstacles can, for example, be trees, stones, or poles.

[0043] [Fig.3A] shows the robot 20 having just left its base 40 according to the movement arrow D. The charging cable 30 has just been delivered and is placed on the ground according to the path of the robot 20. The path that the robot 20 will follow to arrive at the vehicle V is arrowed and the two obstacles O force the robot 20 to change direction.

[0044] [Fig.3B] shows the robot 20 once it has reached its objective under the vehicle V to be recharged. The charging cable 30 is on the ground along the route taken by the robot 20.

[0045] However, a new obstacle X has come to block the charging cable 30. This may be a stone that has been moved, a branch that has fallen, or something else. This new obstacle X has not prevented the robot 20 from progressing towards the vehicle V.

[0046] Figures 3C and 3D show the return path of the robot 20 (travel arrow D) from the vehicle V to its base 40. As it travels, the charging cable 30 is stored by the cable organizer 50 attached to the robot 20. However, when it reaches the proximity of the new obstacle X, the cable organizer 50 can no longer store any cable.

[0047] In order to unblock or unjam the charging cable 30, the charging device 10 executes a specifically designed unjamming device 130 which can implement different curative unjamming strategies.

[0048] A first curative SI strategy consists of pulling the cable in small repeated jolts in the direction of the cable 30. This first SI strategy is symbolized in [Fig.3C] by the double arrow S1-F2. These small jolts do not damage the charging cable 30 but can loosen it.

[0049] A second curative strategy S2 aims to shake the cable 30 transversely to its direction so as to create and send into the recharging cable 30 a train of waves transverse to the direction of the cable 30. These waves form waves which propagate along the cable 30 from the robot 20 to the new obstacle X, trying to unjam the cable 30. These transverse waves are shown in [Fig.3C].

[0050] [Fig.3D] represents, in a Cartesian diagram, the force F necessary to store the cable 30, the force F is low at the start of the path, which indicated to the electronic controller 80 that no obstacle was preventing the robot 20 from moving forward. When the new obstacle X prevents the cable tidy 50 from storing the cable 30, the force F measured by the force sensor 70 increases rapidly beyond a predefined limit force LF stored by the electronic controller 80. This sudden overshoot is interpreted as being characteristic of a blockage of the cable 30, following which, the electronic controller 80 implements the curative unblocking strategies.

[0051] These successive jolts, represented in the number of three, a larger or smaller number is of course possible, are symbolized in [Fig.3D] by three peaks of force FD, successive and short peaks. At the end of these jolts FD, the cable is unstuck and the force F necessary to take up and continue to store the cable 30 becomes low again and lower than the limit force LF.

[0052] In the context of this first alternative to the invention in which the cable organizer 50 is attached to the robot 20, the unblocking device 130 is also attached to the robot 20 and it implements the curative unblocking strategies.

[0053] According to a simple alternative of this invention, the cable tidy 50 is a motorized reel capable of unwinding the cable 20 or conversely rewinding it as needed. This motorized reel can integrate the unjamming device 130. Indeed, the first curative strategy SI (pulling the cable in jerks successive) is carried out by operating the reel motor several times consecutively in the winding direction. The second curative strategy S2 (transverse wave trains in the cable) requires, to be implemented, an additional device of the oscillating arm type generating the transverse waves in the cable 30.

[0054] Figures 4A, 4B, 4C, 4D, 4E and 4F show, in the same environment as previously, a second alternative of the recharging device 10 in which the cable organizer 50 is fixed to the base 40. In this case, the cable organizer 50 delivers the cable 30 according to the demand and the distance from the robot 20.

[0055] [Fig.4A] shows the robot 20 having just left its base 40 along the movement arrow D. The two obstacles O force the robot 20 to change direction and the charging cable 30 is barely delivered. The cable 30 traces a path on the ground which may be different from the route followed by the robot 20.

[0056] [Fig.4B] shows that during the progression of the robot 20, a new obstacle X has jammed the cable 30 while the robot 20 has not yet reached its goal. The jamming of the cable 30 prevents the robot 20 from progressing and, to continue its journey, the curative unblocking strategies S1, S2, previously explained, must be implemented.

[0057] [Fig.4B] represents the first curative unjamming strategy SI (arrow S1-F2; pull the cable in successive jerks) or the second curative strategy S2 (wave trains transverse to the cable) generated from the base 40. In this case the cable tidy 50 can be a reel in which the unjamming device 130 is integrated.

[0058] [Fig.4C] represents the situation of [Fig.4B] once the cable 30 is unstuck, the robot 20 having reached the vehicle V to be recharged. The cable 30 placed on the ground marks a path different from the route taken by the robot.

[0059] [Fig.4D] shows the return path of the robot 20 to its base 40. A new obstacle X then jams the cable 30 and, once again, the curative unblocking strategies, using SI pulses and S2 wave trains, must be implemented.

[0060] [Fig.4E] illustrates the implementation of the curative unjamming strategies SI, S2, from the robot and no longer from the base 40. In this case, the unjamming means 130 is distinct from the organizer 50 and is fixed to the robot 20.

[0061] [Fig.4F] presents a third curative unjamming strategy S3 in which the robot 20, held by the cable 30 jammed by the obstacle X, changes directions (curved arrow) and tries to move forward in the direction opposite to the obstacle X. The robot 20 pulls on the cable 30 in jerks in several directions.

[0062] This third curative strategy S3 can be implemented by means of the unjamming device 130 responsible for pulling the cable 30 while the change of direction is the work of robot 20.

[0063] This third curative strategy S3 can also be implemented by the robot alone which, after having changed direction, tries to move in the opposite direction of the obstacle so as to pull on the cable 30.

[0064] The curative unblocking strategies presented separately can of course, for greater effectiveness, be implemented jointly.

[0065] In addition to the curative unjamming strategies, the recharging device 10 implements a preventive anti-jamming strategy S0 and a permanent anti-jamming strategy SP.

[0066] Figures 5A and 5B schematically illustrate different alternatives of cables 30. [Fig.5A] presents four alternatives of cable section and, [Fig.5B] presents two three-dimensional alternatives of the cable 30.

[0067] The charging cable 30 comprises an outer sheath 90, electrically insulating, and surrounding power wires 100 (shown as three in number) making it possible to conduct the electrical power necessary for recharging a vehicle and a heating wire 110. Three power wires 100 are shown although the invention applies to other cables having a different number of power wires.

[0068] The preventive anti-jamming strategy S0 used by the charging device 10 is the heating of the cable 30 by means of this heating wire 110. The temperature sensor 140 attached to the robot 20 indicates whether there is a risk of snow or ice. Also, to anticipate a possible jamming of the cable 30 by snow or ice that forms quickly, the preventive anti-jamming strategy S0 consists of heating the cable 30 to a temperature of approximately 20 or 30 Celsius, without damaging the cable by too high a temperature or making it hot. The heating is done using the heating wire 110 which is a “low voltage” wire, for example 12 or 24 Volts, with a smaller cross-section than the power wires 100.

[0069] The S0 anti-jamming preventive strategy triggers the heating of the cable 30 depending on the outside temperature measured by the temperature sensor 140. If the temperature is close to zero Celsius, the heating is activated.

[0070] Alternatively, the heating may be activated continuously, regardless of the ambient temperature, and in this case, the temperature sensor 140 is not useful.

[0071] The permanent anti-jamming strategy SP consists of proposing a cable 30 whose sheath 90 has asperities 120. The outer sheath 90 can be smooth but, it has appeared that a sheath having asperities makes it possible to reduce the force F necessary to deliver the cable or to store it. This is due to the fact that the contact surface between the cable 30 and the ground is less if the sheath has asperities.

[0072] Figures 5A and 5B show diagrammatically examples of sections of charging cable 30 having asperities 120. Whether they are numerous, regular, or re have grooves along the charging cable 30 or individual spikes, the roughnesses 120 make it possible to reduce the surface area of ​​the cable in contact with the ground and therefore to reduce the effort required to deliver or store the charging cable 30.

[0073] [Fig.6] illustrates a recharging method 160 stored and executed by the electronic controller 80. The recharging method 160 comprises:

[0074] - a sub-process 200 for unjamming the cable 30; the sub-process for unjamming 200 itself comprising the following steps:

[0075] - a temperature measurement step 180 carried out before any movement of the robot 20. During this temperature measurement step 180 the ambient temperature around the robot 20 is measured by the temperature sensor 140. Knowing this ambient temperature is important because, if it is close to zero Celsius, or even below, it indicates a risk of snow, ice or other atmospheric conditions and difficult terrain.

[0076] If a temperature close to or below zero Celsius is measured, then the unjamming sub-process 200 activates the anti-jamming preventive strategy S0 by engaging a heating step 190 of the cable 30 to approximately 20 or 30 Celsius. The progression of the temperature of the cable during this heating step 190 is variable.

[0077] At the end of this heating step 190, or if a temperature is measured which does not indicate a risk of snow or ice, the recharging method 160 initiates a movement step 170 during which the robot 20 follows a path towards a vehicle V to be electrically recharged, or a return path towards the base 40.

[0078] The sub-process 200 for unjamming the cable 30 also comprises the following steps:

[0079] - a force measurement step 210, a step during which the force F required to the cable tidy 50 for delivering or storing cable is measured by the force sensor 70. The measured force F is then compared to the predefined force limit LF and stored in the electronic controller 80. If this force F is less than the force limit LF, then the cable is not stuck and the robot 20 continues its path according to the movement step 170. If, on the other hand, the force F is greater than the force limit LF then it is concluded that the cable 30 is stuck by an obstacle X.

[0080] - a dejamming step 220 engaged if it is concluded at the force measurement step 210 that the cable 30 is stuck. During the unjamming step 220 the method implements curative unjamming strategies S1, S2, S3. These curative strategies can be implemented jointly or separately.

[0081] The first curative SI unjamming strategy aims to pull on the cable 30 in successive jerks along the main direction of the cable 30. This first SI strategy curative strategy is implemented by the unjamming device 130 which pulls on the cable trying to store it or by the robot 20 which tries, by pulling on the cable, to move away from the obstacle X which jams the cable 30. Insofar as the cable tidy 50 is a motorized reel, this first curative strategy SI can be implemented directly by the reel whose motor is actuated in jerks so as to pull on the cable 30.

[0082] The second curative unjamming strategy S2 aims to shake the cable 30 in a direction perpendicular to the main direction of the cable 30 so as to create in the cable 30 a train of waves forming waves which propagate along the cable 30 in the direction of the obstacle X. This second curative strategy S2 is implemented by the unjamming device 130. Insofar as the cable tidy 50 is a motorized reel, the reel is provided, for example, with a specific oscillating arm or rotating index (not shown) acting on the cable 30. The waves sent into the cable 30 can be created parallel or perpendicular to the ground or in any intermediate direction.

[0083] The third curative unjamming strategy S3 has the aim, similarly to the first curative strategy SI, of pulling on the cable 30 in successive jerks along the main direction of the cable 30 but these pulls are combined with changes in position of the motorized robot 20. Thus, this third curative strategy S3 is implemented jointly by the unjamming device 130 which pulls on the cable 30 trying to store it and by the robot 20 which changes position so that the pulling carried out by the unjamming device 130 is done in different directions. This third curative strategy S3 can also be implemented by the robot 20 alone which changes position and tries to move away from the obstacle X so that it pulls on the cable 30.

[0084] The unblocking method 200 also comprises a timing step 230 during which the duration of execution of the unblocking step 220 is measured. As long as this duration is less than a predefined time limit, the method continues in a loop between the measurement 210, unblocking 220 and timing steps continuing to execute the curative unblocking strategies.

[0085] This loop is carried out several times until the force F measured by the force sensor 70 has become lower than the force limit LF, then the unjamming method 200 is interrupted and returns to the movement step 170, the robot 20 continuing its journey.

[0086] If, on the other hand, the force F measured for pulling the cable is still greater than the limit force LF when the cumulative time of the unjamming step 220 (time measured during the timing step 230) reaches the time limit LT then the unjamming method 200 interrupts the unjamming step 220 and initiates an alert step 240. during which the robot 20 stops and the charging device 10 signals a fault. This alert can be of any nature such as a flashing red light, an audible signal, a message sent to a mobile phone.

Claims

Claims

1. Device (10) for recharging by induction or conduction an electric vehicle (V), the device comprising a fixed base (40), a motorized robot (20) capable of moving and a recharging cable (30) connecting the robot (20) to the base (40), the recharging cable (30) comprising an outer sheath (90) enveloping wires (100), in particular power wires transmitting the electrical or control power, characterized in that the recharging device (10) further comprises a means for heating the cable (30).

2. Charging device (10) according to claim 1 characterized in that the heating means of the cable (30) is a heating wire (110) arranged inside the sheath (90) of the charging cable (30) in parallel with the wires (100).

3. Charging device (10) according to any one of claims 1 to 2 characterized in that the charging device (10) further comprises a cable organizer (50), a means (130) for unjamming the cable (30), a temperature sensor (140) and an electronic controller (80) capable of controlling the unjamming means (130).

4. Charging device (10) according to any one of claims 1 to 3, characterized in that the outer sheath (90) of the cable (30) has roughnesses (120).

5. A charging method (160) implemented during the charging of an electric vehicle by an induction or conduction charging device (10) according to any one of claims 1 to 4, the induction or conduction charging device (10) further comprising a force sensor (70) capable of measuring a force (F) necessary to unwind or store the charging cable (30), the charging method (160) comprising a sub-method (200) of unjamming the charging cable (30), the unjamming sub-method (200) comprising a step of measuring (210) the force (F) necessary to unwind or store the charging cable (30), a step during which the force (F) is compared to a limit force (LF), if said force (F) is strictly greater than said limit force (LF) then a step of unjamming (220) the cable is implemented, a step during which a curative strategy (SI, S2,S3) of unjamming the cable (30) comprising a step of generating successive jolts in the cable (30) by traction or by shaking in the direction transverse to the direction of said cable (30).,

6. Recharging method (160) according to claim 5 characterized in that the sub-method (200) implements a preventive anti-jamming strategy (S0) comprising a step of measuring ambient temperature (180) and a step of heating (190) the recharging cable.

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