Method for controlling a charging infrastructure

Abstract

The present invention relates to a method for controlling a charging infrastructure, which charging infrastructure includes a charging station for charging a vehicle having a vehicle-side charging interface, wherein the charging station includes a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, wherein the robot includes a main base and a compliance component, which compliance component is kinematically arranged between the main base and the robot-side charging interface for providing compliance, wherein the method sequentially includes a positioning phase in which the robot-side charging interface is moved to an initial connection position, and a connection phase in which the robot-side charging interface establishes a charging connection with the vehicle-side charging interface, wherein in the positioning phase, a compliance value is compared with a positioning intervention value, and the positioning instruction is changed when the compliance value exceeds the positioning intervention value, and in the connection phase, the compliance value is compared with a connection intervention value, and the connection instruction is changed when the compliance value exceeds the connection intervention value, wherein the positioning intervention value is different from the connection intervention value.

Description

Technical Field

[0001] The present invention relates to a method for controlling a charging infrastructure, which includes a charging station for charging a vehicle having a vehicle-side charging interface, and a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface.

[0002] Furthermore, the present invention relates to a charging infrastructure, which includes a charging station for charging a vehicle having a vehicle-side charging interface, and a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface. Background Art

[0003] Electric vehicles must be frequently charged by connecting them to a battery charger. In recent years, attempts have been made, for example, by implementing fast-moving and precise robots programmed to bring a robot-side charging interface into a vehicle-side interface. However, such complex peg-in-hole tasks require a high-precision and thus expensive robot implementation for each charging infrastructure, where the robot may still be unsuitable for safely handling abnormal situations such as deviations in the position of the vehicle-side charging interface or accidental physical contact with an object between the robot-side interface and the vehicle-side interface. Summary of the Invention

[0004] An object of the present invention is to provide a charging infrastructure with a robot and a method for controlling the charging infrastructure that can safely handle abnormal situations as described above.

[0005] According to a first aspect, the present invention provides a method for controlling a charging infrastructure, the charging infrastructure comprising a charging station for charging a vehicle having a vehicle-side charging interface, wherein the charging station comprises a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, wherein the robot comprises a main base, a displacement mechanism between the main base and the robot-side charging interface for moving the robot-side charging interface relative to the main base with at least three degrees of freedom, wherein the displacement mechanism comprises at least one actuator configured to apply a displacement between the main base and the robot-side charging interface over a displacement stroke when the actuator is actuated, wherein the robot comprises a compliance assembly arranged kinematically in series with the actuator between the main base and the robot-side charging interface, wherein the compliance assembly is configured to provide compliance by elastically absorbing or releasing a displacement between the base frame and the robot-side charging interface over a compliance stroke, wherein the method sequentially comprises: a positioning phase, wherein the robot-side charging interface is moved from a retracted position in which the vehicle can enter or leave the charging station to an initial connection position in which the robot-side charging interface is in front of the vehicle-side charging interface and preferably aligned with the vehicle-side charging interface; a connection phase, wherein the robot-side charging interface establishes a charging connection with the vehicle-side charging interface from the initial connection position; a charging phase, wherein the vehicle is charged by a charging current through the robot-side charging interface; and a disconnection phase, wherein the robot-side charging interface disengages from the vehicle-side charging interface and retracts towards the retracted position, wherein in the positioning phase, the actuator is powered according to a positioning command, the compliance is monitored, the compliance value is compared with a positioning intervention value, and the positioning command is changed when the compliance value exceeds the positioning intervention value, and wherein in the connection phase, the actuator is powered according to a connection command, the compliance is monitored, the compliance value is compared with a connection intervention value, and the connection command is changed when the compliance value exceeds the connection intervention value, wherein the positioning intervention value is different from the connection intervention value.

[0006] The charging infrastructure according to the present invention includes a robot having an actuator for moving a robot-side charging interface and a compliance component kinematically in series with the actuator to absorb a part of the movement of the actuator. The compliance can quickly absorb the collision of the robot-side interface with an unexpected object while still powering the actuator, which gives the control system time to respond, and the compliance can be used to allow the robot-side charging interface to establish a correct charging connection with the vehicle-side charging interface through passive compensation of the robot inaccuracy. During the positioning phase, the compliance value is compared with a positioning intervention value, and during the connection phase, the compliance value is compared with a connection intervention value different from the positioning intervention value. Thus, during the positioning phase, the robot may be highly sensitive to any unexpected collision, while during the connection phase, when there is an intentional physical contact, higher values may be allowed, for example, to overcome the friction between the robot-side charging interface and the vehicle-side charging interface that occurs along with the connection establishment, but prevent damage caused by clamping. This can provide a robot that can operate safely in public areas.

[0007] In an embodiment, the positioning intervention value is less than the connection intervention value.

[0008] In a practical embodiment, the positioning intervention value is less than 50% of the connection intervention value.

[0009] In a preferred practical embodiment, the positioning intervention value is less than 25% of the connection intervention value.

[0010] In an embodiment, when the compliance value exceeds the positioning intervention value, the positioning instruction is changed to stop the actuation of the actuator, whereby the compression force applied by the robot-side charging interface is kept limited to the amount absorbed by the compliance component.

[0011] In an embodiment, when the compliance value exceeds the positioning intervention value, the positioning instruction is aborted, and the actuator is powered according to a retraction instruction to retract the robot-side charging interface towards the retracted position.

[0012] In an embodiment, when the compliance value exceeds the connection intervention value, the connection instruction is changed to stop the actuation of the actuator, whereby a certain amount of compression force is allowed to be applied by the robot-side charging interface to overcome the friction between the robot-side charging interface and the vehicle-side charging interface that occurs along with the connection establishment, but prevent damage caused by clamping, which may occur when the compliance value exceeds the connection intervention value.

[0013] In an embodiment, when the compliance value exceeds the connection intervention value, the connection instruction is aborted, and the actuator is powered according to a retraction instruction to retract the robot-side charging interface towards the retracted position or back to the initial connection position.

[0014] In an embodiment, during the charging phase, the actuator is powered according to a charging instruction and the compliance is monitored, wherein the charging instruction defines that the compliance value is brought between a first charging intervention value and a lower second charging intervention value. Specifically, during the charging phase, the actuator is powered according to the charging instruction at the start of the charging phase, and when the compliance value is between the first charging intervention value and the lower second charging intervention value, the actuator preferably remains idle for the remainder of the charging phase. Then, the compliance assembly is balanced to a compliance value between the first charging intervention value and the second charging intervention value. An accidental movement of the vehicle-side charging interface can be passively followed by the robot-side charging interface without violating the intervention value. For example, such an accidental movement may be caused by a person stepping out of the vehicle.

[0015] In an embodiment thereof, when the compliance value exceeds the first charging intervention value or is lower than the second charging intervention value, the actuator is powered according to the charging instruction to bring the compliance value between the first charging intervention value and the second charging intervention value, whereby charging can continue in a safe manner.

[0016] In an embodiment, during the positioning phase, during the connection phase, and during the charging phase, the actuator can be powered according to an intervention instruction and the compliance value is monitored, wherein the compliance value is compared with a warning intervention value, and when the warning intervention value is exceeded, the intervention instruction is initiated, and the intervention instruction is selected from the group comprising:

[0017] - Interrupt the charging current through the robot-side charging interface;

[0018] - Trigger an audible alarm;

[0019] - Trigger a visual alarm;

[0020] - Communicate the alarm status to the vehicle or a higher-level management system;

[0021] - Trigger a mechanical break release; and

[0022] - Retract the robot-side charging interface from the vehicle-side charging interface.

[0023] In an embodiment, during the positioning phase, the warning intervention value is higher than the positioning intervention value; during the connection phase, the warning intervention value is higher than the connection intervention value; and / or during the charging phase, the warning intervention value is higher than the first charging intervention value or lower than the second charging intervention value, or the warning intervention value has a first warning intervention value higher than the first charging intervention value and a second warning intervention value lower than the second charging intervention value.

[0024] In an embodiment, the positioning phase includes the following steps: determining the position of the vehicle-side charging interface, and determining an initial connection position by adding the cumulative system inaccuracy to the determined position of the vehicle-side charging interface or subtracting the cumulative system inaccuracy from the determined position of the vehicle-side charging interface. It is noted that the inventors have found that when the robot-side charging interface is at or near the initial connection position, it is advantageous when there is no physical contact between the robot-side charging interface and the vehicle-side charging interface. Thus, damage to the vehicle caused by the robot-side charging interface moving to the initial connection position can be prevented.

[0025] According to a second aspect, the present invention provides a method for controlling a charging infrastructure, the charging infrastructure including a charging station for charging a vehicle having a vehicle-side charging interface, wherein the charging station includes a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, wherein the robot includes a main base, a displacement mechanism between the main base and the robot-side charging interface for moving the robot-side charging interface relative to the main base with at least three degrees of freedom, wherein the displacement mechanism includes at least one actuator configured to apply a displacement between the main base and the robot-side charging interface over a displacement stroke when the actuator is actuated, wherein the robot includes a compliance component arranged kinematically in series with the actuator between the main base and the robot-side charging interface, wherein the compliance component is configured to provide compliance by elastically absorbing or releasing a displacement between the base frame and the robot-side charging interface over a compliance stroke, wherein the method sequentially includes: a positioning phase, wherein the robot-side charging interface moves from a retracted position in which the vehicle can enter or leave the charging station to an initial connection position in which the robot-side charging interface is in front of the vehicle-side charging interface and preferably aligned with the vehicle-side charging interface; a connection phase, wherein the robot-side charging interface establishes a charging connection with the vehicle-side charging interface from the initial connection position; a charging phase, wherein the vehicle is charged by a charging current through the robot-side charging interface; and a disconnection phase, wherein the robot-side charging interface disengages from the vehicle-side charging interface and retracts towards the retracted position, wherein in the charging phase, the actuator is powered according to a charging instruction and the compliance is monitored, wherein the charging instruction defines that the compliance value is brought between a first charging intervention value and a lower second charging intervention value.

[0026] In an embodiment thereof, in the charging phase, the actuator is powered according to a charging instruction at the start of the charging phase, and when the compliance value is between the first charging intervention value and the lower second charging intervention value, the actuator is preferably idle for the remainder of the charging phase.

[0027] In another embodiment thereof, when the compliance value exceeds a first charging intervention value or is lower than a second charging intervention value, the actuator is powered according to a charging instruction to bring the compliance value between the first charging intervention value and the second charging intervention value.

[0028] In an embodiment, during the positioning phase, during the connection phase, and during the charging phase, the actuator can be powered according to an intervention instruction, and the compliance value is monitored, wherein the compliance value is compared with a warning intervention value, and when the warning intervention value is exceeded, an intervention instruction is initiated, and the intervention instruction is selected from the group including the following:

[0029] - Interrupt the charging current through the robot-side charging interface;

[0030] - Trigger an audible alarm;

[0031] - Trigger a visual alarm;

[0032] - Communicate the alarm status to the vehicle or a higher-level management system;

[0033] - Trigger a mechanical break release; and

[0034] - Retract the robot-side charging interface from the vehicle-side charging interface.

[0035] In an embodiment, during the positioning phase, the warning intervention value is higher than the positioning intervention value; during the connection phase, the warning intervention value is higher than the connection intervention value; and / or during the charging phase, the warning intervention value is higher than the first charging intervention value or lower than the second charging intervention value, or the warning intervention value has a first warning intervention value higher than the first charging intervention value and a second warning intervention value lower than the second charging intervention value.

[0036] According to a third aspect, the present invention provides a charging infrastructure, the charging infrastructure comprising a charging station for charging a vehicle having a vehicle-side charging interface, wherein the charging station comprises a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, wherein the robot comprises a main base, a displacement mechanism between the main base and the robot-side charging interface for moving the robot-side charging interface relative to the main base with at least three degrees of freedom, wherein the displacement mechanism comprises at least one actuator configured to apply a displacement between the main base and the robot-side charging interface over a displacement stroke when the actuator is actuated, wherein the robot comprises a compliance assembly arranged kinematically in series with the actuator between the main base and the robot-side charging interface, wherein the compliance assembly is configured to provide compliance by elastically absorbing or releasing a displacement between the base frame and the robot-side charging interface over a compliance stroke, wherein the charging infrastructure further comprises a controller operatively connected to at least the robot and configured to execute the method according to the first aspect or the second aspect of the present invention.

[0037] According to a fourth aspect, the present invention provides a computer-readable medium having instructions thereon which, when executed by a controller or a processor, cause the charging infrastructure according to the third aspect of the present invention to execute the method according to the first aspect or the second aspect of the present invention.

[0038] The various aspects and features described and illustrated in the specification can be applied separately where possible. These separate aspects, in particular the aspects and features described in the appended dependent claims, can form the subject of a divisional patent application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be described based on exemplary embodiments shown in the drawings, in which:

[0040] Figure 1A , 1B, and 1C are respectively a side view, an isometric rear view, and an isometric front view of details of a charging station with a robot according to a first embodiment of the present invention, the robot having a robot-side charging interface for establishing a charging connection with a vehicle-side charging interface of an electric vehicle;

[0041] Figure 2A and 2B are respectively a side view and an isometric view of details of a charging station with a robot according to a second embodiment of the present invention, the robot having a robot-side charging interface for establishing a charging connection with a vehicle-side charging interface of an electric vehicle;

[0042] Figure 3A and 3BAre an isometric side view and an isometric rear view of the details of a charging station with a robot according to a third embodiment of the present invention, the robot having a robot-side charging interface for establishing a charging connection with a vehicle-side charging interface of an electric vehicle;

[0043] Figure 4 Is as Figure 1A 、 1B 、1C, the robot shown therein, or as Figure 2A And 2B The longitudinal section of the compliance component of the robot shown therein, or as Figure 3A And 3B The longitudinal section of the compliance component of the robot shown therein;

[0044] Figure 5A Is a partial longitudinal section of the robot-side charging interface and the vehicle-side charging interface that are correctly aligned just before the charging connection is to be established, as shown in Figure 1B 、 2B And 3B;

[0045] Figure 5B Is a partial longitudinal section of the robot-side charging interface and the vehicle-side charging interface that have been correctly established for charging, as shown in Figure 5A Therein;

[0046] Figure 5C And 5D Is a partial longitudinal section of the robot-side charging interface and the vehicle-side charging interface during the correction of an allowable misalignment (or misalignment) under the control of the robot, as shown in Figure 5A Therein;

[0047] Figures 6A - 6F Is a graph showing the monitoring of the establishment of a charging connection by means of the compliance component shown in Figure 4 Therein and different possible responses thereto; and

[0048] Figure 7 Is a flowchart of the steps performed during the operation of the robot according to the previous figures. Detailed Description

[0049] Figure 1A 、 1B And 1C show a charging station 1 according to a first embodiment of the present invention. The charging station 1 has a vehicle area 2 for charging an electric vehicle 10 (in this instance, a passenger car). The vehicle 10 can be fully electrically driven, or it can have a hybrid drive in which electric drive is combined with fuel combustion. The vehicle 10 has a body 11 on wheels 12 and a vehicle-side charging interface 20 carried by the body 11, which in this instance is on the right side of the body 11 above one of the rear wheels 12.

[0050] AsFigure 1A , 1B As shown in FIGS. 1B and 1C, the charging station 1 includes a robot 50 having a robot-side charging interface 100 for establishing a charging connection with a vehicle-side charging interface 20. The robot-side charging interface 100 is electrically connected to a battery charger (not shown).

[0051] The specific pin arrangements of the robot-side charging interface 100 and the vehicle-side charging interface 20 can be any known type described in official standards such as the IEC / SAE standard. The robot-side charging interface 100 and the vehicle-side charging interface 20 can belong to the so-called Mennekes, Yazaki, Schuko, or Combo types, or any other dedicated connectors for electric vehicle charging. As Figure 1B and 5A shown in FIGS. 2A and 2B, the vehicle-side charging interface 20 is in this instance a ComboCCS-2 socket that accepts normal charging and high-speed charging. The vehicle-side charging interface 20 includes a front surface 21 that merges inwardly into a circumferential inner surface 22. The inner surface 22 merges into a bottom surface 23, and a first socket 24 and a second socket 31 project from the bottom surface. The first socket 24 includes a socket body 25 of electrically insulating material having five first channels 26 in which five recessed normal charging connectors 27 extend, and two second channels 28 in which two control connectors 29 extend. The second socket 31 includes a socket body 32 of electrically insulating material having two third channels 33 in which two high-speed charging connectors 34 extend. The inner surface 22 and the socket bodies 25, 34 together define a groove 30 around the sockets 24, 31. The groove 30, the first channels 26, the second channels 28, and the third channels 33 have a receiving direction R designed to be parallel to the first channels 26, the second channels 28, and the third channels 33.

[0052] As Figure 1C and 5A shown in FIGS. 3A and 3B, the robot-side charging interface 100 is in this instance the so-called Mennekes type (type 2 connector under IEC 62196) for normal charging. The robot-side charging interface 100 includes a shroud 101 that mates with and fits inside the groove 30 of the vehicle-side charging interface 20, and a plurality of first bushings 102 and second bushings 103 that mate with and fit inside the corresponding first channels 26 and second channels 28 of the vehicle-side charging interface 20. The robot-side charging interface 100 includes charging connectors that are recessed inside the bushings 102, 103 and are electrically connected to the connectors 27, 29 of the vehicle-side charging interface 20 when a charging connection is established. The shroud 101, the first bushings 102, and the second bushings 103 have an insertion direction P designed to be parallel to the charging connectors. The insertion direction P is designed to be exactly parallel and aligned with the receiving direction R of the vehicle-side charging interface 20.

[0053] The vehicle-side charging interface 20 and the robot-side charging interface 100 usually have a very precise mating geometry, which allows only a slight misalignment of about 0.1 - 0.3 mm maximum transverse to the receiving direction R or a slight misalignment of 1 - 2 degrees maximum when manually inserted into each other at the initial mutual contact. Due to the self-searching shape features of the charging interfaces 20, 100, this minimal misalignment is automatically corrected, whereby the charging interfaces 20, 100 enter into the correct mutual engagement. The connectors 27, 29, 34 of the vehicle-side charging interface 20 and the connectors 102, 103 of the robot-side charging interface 100 may have different lengths or positions in the insertion direction P and the receiving direction R to impose a default mating sequence between the contacting connectors, even if they have the above-mentioned slight misalignment. This ensures, for example, the establishment of a ground connection or a control connection before making the power connection. The vehicle-side charging interface 20 is inserted into the robot-side charging interface 100 along the insertion direction P during an insertion stroke, which ends when the design depth of the correct insertion is reached. The vehicle-side charging interface 20 and the robot-side charging interface 100 are provided with a remote control lock for locking the vehicle-side charging interface 20 at its design depth. This is to physically prevent the correctly connected charging interfaces 20, 100 from disengaging during the application of a high charging current.

[0054] As Figure 1A shown, the robot 50 of the charging station 1 includes a schematically shown base or main base 51, which has a main frame 52, which in this instance is located on the ground next to the vehicle area 2 on the side close to the vehicle-side charging interface 20. The robot 50 can be located on any side, or at the front side or the rear side of the vehicle 10 depending on the position of the vehicle-side charging interface 20. Alternatively, the robot 50 is positioned on the floor or under the floor to reach the vehicle-side charging interface 20 at the bottom side of the vehicle 10, or the robot 50 is suspended above the vehicle 10 to reach the vehicle-side charging interface 20 located at the top side or on the roof of the vehicle 10.

[0055] As Figures 1A - 1C shown, the robot 50 includes a movable carrier 60 having a carrier frame 61 carrying the robot-side charging interface 100. The robot 50 can belong to any configuration that enables the movable carrier 60 and thus the robot-side charging interface 100 to move relative to the main base 51. A Cartesian coordinate system O is mathematically defined, which is coupled to the main base 51 and to which the position of the robot-side charging interface 100 is related. The robot-side charging interface 100 can be translated in any one of three orthogonal directions X, Y, Z (lateral, longitudinal, and vertical) and can rotate (pitch, roll, yaw) about these axes relative to the main base 51, for a total of six degrees of freedom (6-DOF) or less, depending on its specific transmission chain configuration.

[0056] In this example, the robot 50 includes a robot base 54 that rotates about a vertical first axis D corresponding to the Z-axis of the Cartesian coordinate system O via a first rotary actuator 53 connected to the main frame 52. The robot 50 includes a first robotic arm 56 that rotates about a horizontal second axis E relative to the main frame 52 via a second rotary actuator 55 connected to the robot base 54 at one end. The first robotic arm 56 rotates the second arm 58 about a third horizontal axis F relative to the first arm 56 via a third rotary actuator 57 connected to one end of the second robotic arm 58 at its opposite end. The opposite end of the second robotic arm 58 is connected to the movable carrier 60 via a fourth rotary actuator 59 to rotate the movable carrier 60 relative to the second arm 58 about a horizontal fourth axis G and about fifth and sixth axes H and J that are orthogonal to each other.

[0057] As Figure 4 best shown in, the robot 50 includes a first compliance assembly 90a that is connected in series between the movable carrier 60 and the robot-side charging interface 100 and is thus kinematically connected in series with at least one of the rotary actuators 53, 55, 57, 59 of the robot-side charging interface 100 and the transmission chain. A Cartesian coordinate system C coupled to the robot-side charging interface 100 and related to compliance is defined mathematically, where the Y-axis is preferably parallel to the insertion direction P. The compliance assembly 90a provides mechanical compliance between the transmission chain and the robot-side charging interface 100.

[0058] In this example, the compliance assembly 90a includes an outer tube 91 mounted to the carrier frame 61 and a link 92 linearly guided inside the outer tube 91 by means of a sliding bearing 93 in this example. The link 92 projects partially from the outer tube 91, and in this example, the first compliance assembly 90a includes an end stop 94 at the end of the link 92 that is held behind the sliding bearing 93 to define the outermost position of the link 92 relative to the carrier frame 61; and a reversible flexible element, in this example a spring, in particular a helical spring 95 between the end stop 94 and the carrier frame 61, which is biased to keep the end stop 94 adjacent to the sliding bearing 93. In this example, when a defined threshold force is exceeded (which overcomes the bias of the helical spring 95), the link 92 can elastically and reversibly slide back in the compliance stroke in the direction L towards the movable carrier 60 by means of the helical spring 95. Thus, the first compliance assembly 90a provides a first compliance in the direction L. The rotary actuators 53, 55, 57, 59 apply a displacement to the robot-side charging interface 100, and as long as the threshold force on the compliance assembly 90a is not exceeded, the robot-side charging interface 100 follows this displacement.

[0059] In the embodiment, the first compliance component 90a is biased to and against the sliding bearing 93. Alternatively, the helical spring 95 or any other elastic element provides elasticity in the opposite direction with or without the application of a threshold force, whereby the link 92 can be elastically and reversibly pushed towards and pulled away from the movable carrier 60. Both embodiments provide a compliance stroke of one degree of freedom.

[0060] As Figure 4 shown, the first compliance component 90a includes a distance sensor 110 schematically shown, which is positioned and configured to provide an electrical signal via a first cable 111. The electrical signal indicates the distance of the end stop 94 relative to the movable carrier frame 61 and thus indicates the length of the first compliance in the direction L and the external force applied in this direction L. The first compliance component 90a includes an end switch 115, which is positioned and configured to detect the abutment of the end stop 94, which indicates the situation of reaching the maximum length of the first compliance. Then, the end switch 115 provides a corresponding signal via a second cable 116.

[0061] Figure 2A and 2B A charging station 201 with a robot 250 according to a second embodiment of the present invention is shown. Parts corresponding to the first embodiment are provided with the same reference numerals. Only the deviating parts will be discussed below.

[0062] The robot 250 includes a plurality (six in this embodiment) of compliance components 90a - 90f between the movable carrier 60 and the robot - side charging interface 100. In the figure, only three of them are shown in detail. The movable carrier 60 includes a total of six leg supports 97a - 97f on the carrier frame 61, which are in the same plane and form pairs in a triangular configuration. The robot 250 includes a total of six leg supports 96a - 96f on the robot - side charging interface 100, which are in the same plane and form pairs in a triangular configuration. The outer tube 91 of the compliance components 90a - 90f has a first connector 98, which is embodied as a universal rotary joint with two degrees of freedom and is connected to the leg supports 97a - 97f of the movable carrier 60. The link 92 of the compliance components 90a - 90f has a second connector 99, which is embodied as a universal rotary joint with three degrees of freedom and is connected to the leg supports 96a - 96f on the charging interface 100. In this example, the six compliance components 90a - 90f form a hexapod mechanism between the robot - side charging interface 100 and the movable carrier 60 to provide compliance in six degrees of freedom. Alternatively conceived, the six compliance components 90a - 90f form a Stewart platform between the robot - side charging interface 100 and the movable carrier 60. The compliance components 90a - 90f are thus configured to be parallel to each other and in series with at least one of the robot - side charging interface 100 and the rotary actuators 53, 55, 57, 59 of the drive chain. The helical springs 95 in the individual compliance components 90a - 90f may have different impedances (different stiffnesses in this example) to ensure the default position of the robot - side charging interface 100 relative to the movable carrier 60 without sagging due to uneven weight distribution caused by, for example, the different individual weights of the various components present in the robot - side charging interface 100 and the compliance components 90a - 90f. Each compliance component 90a - 90f is provided with a distance sensor 110 and an end switch 115. The rotary actuators 53, 55, 57, 59 apply a displacement to the vehicle - side charging interface 100, and the vehicle - side charging interface 100 follows this displacement as long as the threshold force on any of the compliance components 90a - 90f is not exceeded.

[0063] Figure 3A and 3B Fig. shows a charging station 301 with a robot 350 according to a third embodiment of the present invention. Parts corresponding to the first embodiment are provided with the same reference numerals. Only the deviating parts will be discussed below.

[0064] The robot 350 includes a main base 51 supported by a console 3 beside a vehicle area 2 on a side close to a vehicle-side charging interface 20 in this instance. The main base 51 includes a main frame 52 and a total of six leg supports 353a - 353f on the main frame 52, which are in the same plane and form pairs in a triangular configuration. The robot 350 includes a movable carrier 60 having a carrier frame 61, and a total of six leg supports 364a - 364f on the carrier frame 61, which are in the same plane and form pairs in a triangular configuration, wherein the distance between the paired leg supports 353a - 353f of the main base 51 is less than the distance between the paired leg supports 353a - 353f of the main base 51. The carrier 60 carries a robot-side charging interface 100.

[0065] In this instance, the robot 350 includes a total of six parallel displacement components between the main base 51 and the movable carrier 60, which are embodied as six legs 371a - 371f extending between the leg supports 353a - 353f of the main base 51 and the leg supports 364a - 364f of the movable carrier 60. The legs 371a - 371f are structurally identical and will be described in detail below by referring to the first leg 371a.

[0066] The first leg 371a includes a linear motion actuator 380 having an outer tube 381, which is connected to the leg support 353a of the main base 51 at its bottom end via a first connector 388, and the first connector is embodied as a universal rotary joint having two degrees of freedom. In this instance, the linear motion actuator 380 has a motor 383 mounted to the outer tube 381. The linear motion actuator 380 has a drive rod 382, which is linearly guided inside the outer tube 81 and partially protrudes from the outer tube 381. The drive rod 382 is operably connected to the motor 383 via a main shaft, for example. As Figure 3A shown, the drive rod 382 thus reciprocates linearly in the displacement stroke relative to the first connector 388 in the direction M by correspondingly powering the motor 383. The linear motion actuator 380 has an internal sensor for measuring the position of the drive rod 382 relative to the outer tube 381, such as a revolution sensor or a revolution counter on the main shaft. Thus, each of the legs 371a - 371f has such a sensor.

[0067] Each of the legs 371a - 371f includes a respective compliance component 90a - 90f in series with a linear actuator 380, where the outer tube 91 is fixed to the drive rod 382, and the link 92 has a respective second coupling 396 embodied as a three - degree - of - freedom universal rotary joint connected to the leg supports 364a - 364f on the carrier frame 61. The helical springs 95 of the compliance components 90a - 90f in each of the legs 371a - 371f may have mutually different impedances (different stiffnesses in this example) to ensure the default position of the robot - side charging interface 100 without sagging due to uneven weight distribution caused by the different individual weights of the various components present in the robot 50, for example.

[0068] In this example, the six legs 371a - 371f form a hexapod mechanism 70 between the main base 51 and the movable carrier 60. Alternatively conceived, the six legs 371a - 371f form a Stewart platform. The linear actuator 80 applies a displacement between the first coupling 388 and the second coupling 389, and as long as a threshold force on the compliance component 90 is not exceeded, the movable carrier 60 and thus the vehicle - side charging interface 100 follow this displacement. The movable carrier 60 can thus be translated in three orthogonal directions X, Y, Z (lateral, longitudinal, and vertical) and rotated about these axes (pitch, roll, yaw), a total of six degrees of freedom (6 - DOF). When the threshold force is exceeded, a part of the displacement applied between the first coupling 388 and the second coupling 389 can be reversibly absorbed by the compliance components 90a - 90f.

[0069] Alternatively or in addition, the movable carrier 60 includes sensors 366, such as a pressure sensor matrix, between the carrier frame 61 and the robot - side charging interface 100 as shown in Figure 3A to obtain or derive the above - mentioned compliance data in six degrees of freedom.

[0070] In the above - mentioned embodiments, the rotary actuators 53, 55, 57, 59 or the motors 383 form a positioning embodiment. The applied compliance components 90a - 90f in series therewith form a compliance embodiment.

[0071] The charging stations 1, 201, 301 include an electronic control system for controlling the operation of the charging station 1. The electronic control system may include one or more imaging detectors 130, such as cameras forming a stereo camera or multiple cameras, or distance sensors, such as LIDAR, radar, or LED-based sensors, to detect the position of the vehicle-side charging interface 20 of the vehicle in the charging station 1. Thus, the imaging detector 130 forms part of the vision system. The imaging detector 130 may be mounted on a base, such as mounted on the main base 51, or carried by a robot 50, such as on the robot-side charging interface 100 as shown in the figure.

[0072] The control system includes an electronic controller connected to the rotary actuators 53, 55, 57, 59 or motors 383 to power their rotation and control their rotation. The electronic controller is connected to the detector 130, connected to the (multiple) distance sensors 110 via the (multiple) first cables 111, and connected to the (multiple) end switches 115 via the (multiple) second cables 116. The charging stations 1, 201, 301 may also include a redundant electronic control system connected to the (multiple) end switches 115, where the above control system is the main control system. In certain extreme situations detected by the end switches 115, for example, the redundant control system may ultimately intervene or override the main control system. The control system may be connected to a battery charger for charging via bushings 102, 103 and receive feedback indicating that the robot-side charging interface 100 is correctly inserted into the vehicle-side charging interface 20, for example, by detecting the matching sequence of the contact connectors inside the vehicle-side charging interface 20 and the robot-side charging interface 20. The electronic controller may communicate with the remote control lock between the vehicle-side charging interface 100 and the robot-side charging interface 100 to determine the actual state of the lock, or lock the correctly inserted robot-side charging interface 100 during vehicle 10 charging, or detect a poor or incomplete insertion.

[0073] The electronic controller is configured to determine the spatial position and orientation of the vehicle-side charging interface 20 in the charging station 1. This may be performed with the aid of the above vision system, or it may be derived from a database including position data of the vehicle-side charging interface 100 of known vehicles (including specific position data of parked vehicles 10), or it may be derived from communication with the vehicle 10 or from an auxiliary control system. A coordinate system S is mathematically defined, which is coupled to the vehicle-side charging interface 20 to determine its position in three orthogonal directions X, Y, Z and any rotational direction about these axes, where the Y-axis is preferably parallel to the receiving direction R.

[0074] The electronic controller is configured to determine the resultant force and resultant moment acting on the robot-side charging interface 100 based on the compliance stroke in the direction L of the applied individual compliance components 90a - 90f. Mathematically, this is expressed with the following stiffness matrix and coordinate system C:

[0075] |F x | |k x 0 0 0 0 0| |Δx|

[0076] |F y | |0 k y 0 0 0 0| |Δy|

[0077] |F z | = |0 0 k z 0 0 0| |Δz|

[0078] |M x | |0 0 0 k rx 0 0| |Δφ|

[0079] |M y | |0 0 0 0 k ry 0| |Δθ|

[0080] |M z | |0 0 0 0 0 k rz | |Δψ|

[0081] In this matrix, F x 、F y 、F z are force components in newtons along the coordinate system axes, M x 、M y 、M z are torques about the coordinate system axes in newton meters, Δx, Δy, Δz are displacement components in meters, and Δφ, Δθ, Δψ are rotation components in radians, all expressed in the coordinate system C. The stiffness components k x 、k y 、k z 、k rx 、k ry 、k rz are related to the stiffness characteristics of the applied helical spring 95 in newtons per meter and newton meters per radian and depend on the current values of the specific construction and the compliance travel. When the compliance is constrained in a specific construction such that the applied compliance is less than the maximum six degrees of freedom, significantly higher stiffness components are applied.

[0082] The force components and torque components acting on the robot-side charging interface 100 or applied by the robots 50, 250, 350 to the charging interface 100 are quantitatively related to the compliance travel defined in the displacement and rotation directions of the coordinate system C. The following typical quantitative relationships apply.

[0083] The following quantization defines a possible range of stiffness and a possible range of compliance travel for each direction in coordinate system C, and the stiffness and compliance travel according to embodiments of the present invention will lie within said ranges. The compliance travel is expressed in meters or degrees respectively. The stiffness is expressed in kilonewtons per meter and kilonewton meters per radian respectively.

[0084] Direction Stiffness Travel

[0085] X [0.25, 40] [0.005, 0.1]

[0086] Y [0.25, 40] [0.005, 0.1]

[0087] Z [0.25, 40] [0.005, 0.1]

[0088] RX [0.005, 6] [0.5, 15]

[0089] RY [0.005, 6] [0.5, 15]

[0090] RZ [0.005, 6] [0.5, 15]

[0091] The following quantization defines a maximum range of stiffness and a maximum range of compliance travel for each direction in coordinate system C, and the stiffness and compliance travel according to embodiments of the present invention will lie within said ranges. The compliance travel is expressed in meters or degrees respectively. The stiffness is expressed in kilonewtons per meter and kilonewton meters per radian respectively.

[0092] Direction Stiffness Travel

[0093] X [0.1, 200] [0.002, 0.25]

[0094] Y [0.1, 200] [0.002, 0.25]

[0095] Z [0.1, 200] [0.002, 0.25]

[0096] RX [0.001, 24] [0.25, 30]

[0097] RY [0.001, 24] [0.25, 30]

[0098] RZ [0.001, 24] [0.25, 30]

[0099] The electronic controller is configured to determine the position and orientation of the robot-side charging interface 100 in the coordinate system O based on the feedback from the rotary actuators 53, 55, 57, 59 or the motor 383, the compliance components 90a - 90f, and by using a vision system.

[0100] The charging station 1 forms part of a charging infrastructure that has a remote computer server for communicating with and configuring the electronic controller. The electronic control system is loaded with software executed by the processor of the electronic controller, whereby the charging station 1 performs the operations as explained below.

[0101] The explanation of the operation of the charging stations 1, 201, 301 starts with the robot 50, 250, 350 being in the fully retracted position, whereby the robot-side charging interface 100 is withdrawn from the vehicle area 2 in the standby position to allow the vehicle 10 to enter the charging stations 1, 201, 301. As Figure 1A schematically indicated, in this fully retracted position, the robot-side charging interface 100 is at a schematically indicated distance Q from the vehicle 10 that will stop in the vehicle area 2 (in particular from the vehicle-side charging interface 20). The operation will be explained below with reference to the charging station 1 according to the first embodiment, where the differences from the charging stations 201, 301 according to the second and third embodiments will be explained where applicable. Figure 6A is a graph showing the first compliance value C1, for example in millimeters, provided by the sole first compliance component 90a of the charging station 1 according to the first embodiment or by the plurality of compliance components 90a - 90f according to the second and third embodiments, where for illustrative purposes only the first compliance C1 and the second compliance C2 of the first compliance component 90a and the second compliance component 90b are plotted. The horizontal axis indicates the elapsed time in seconds.

[0102] In Figure 6A the graph, specific reference values of the compliance are plotted. In the figure, the noise threshold CN indicates the maximum value that is negligible for the first compliance C1 and the second compliance C2, as it does not affect the normal operation of the robots 50, 250, 350. These small values for the compliance C1, C2 may typically be caused by vibrations in the drive train of the robots 50, 250, 350 that act on the robot-side vehicle interface 100 via one or more of the compliance components 90a - 90f. As described below, the other values CP, CC, CH1, CH2 indicate the maximum or minimum values that trigger a specific intervention when exceeded.

[0103] Thereafter, first with reference to Figure 6A and 7 the ideal charging cycle is described, which is not disturbed by external influences or by obstacles between the engaging charging interfaces 20, 100.

[0104] In a first step 310, the presence of the particular vehicle 10 at the vehicle area 2 is notified by registration by means of the imaging detector 130, or by any other suitable sensor, or by any type of data communication between the vehicle 10 and the charging station 1, or by any type of remote trigger system, or by the driver of the vehicle 10 or an operator on site at the charging station 1.

[0105] When the presence or impending presence of the vehicle 10 is notified, then in a second step 320, the spatial position and orientation of the vehicle-side charging interface 20 in the charging station 1 are determined by means of the imaging sensor 130 or based on a database including position data of the vehicle-side charging interface 20 of the known vehicle 20, or derived from communication with the vehicle 20 or obtained from an auxiliary control system. This includes the position in three orthogonal directions X, Y, Z and any rotational orientation about these axes.

[0106] In a third step 330, a corresponding specific initial connection position of the robot-side charging interface 100 relative to the vehicle-side charging interface 20 is determined. The initial connection position is defined as the position where the robot-side charging interface 100 is in front of the vehicle-side charging interface 20 but has not yet contacted the vehicle-side charging interface. The initial connection position is determined by: determining the position of the vehicle-side charging interface 20 and then subtracting and / or adding the maximum cumulative system inaccuracies, such as sensor and actuator inaccuracies, from the determined spatial position and orientation of the vehicle-side charging interface 20. Mathematically, at this position, the Euclidean distance T between any physical part of the robot-side charging interface 100 and the vehicle-side charging interface 20 is at most 10 mm, and preferably at most 5 mm. In the initial connection position, the robot-side charging interface 100 and the vehicle-side charging interface 20 are aligned with a misalignment distance of at most 5 mm, preferably at most 3 mm, transverse to the receiving direction R. In the initial connection position, the robot-side charging interface 100 and the vehicle-side charging interface 20 are aligned with a deviation angle of at most 3 - 5 degrees, preferably 2 degrees, more preferably at most 1 degree. These deviations may be greater than the deviations allowed by the self-search shape features of the charging interfaces 20, 100, since these deviations can be corrected under the application compliance described below. In the initial connection position, it is practically impossible to encounter physical obstacles such as between human hands.

[0107] In a fourth step 340, the rotary actuators 53, 55, 57, 59 or the motor 383 are powered individually while controlling their rotational positions to bring the robot-side charging interface 100 into the determined initial connection position, taking into account the maximum cumulative system inaccuracies determined for the internal position of the transmission chain.

[0108] The second step 320, the third step 330, and the fourth step 340 form part of a positioning phase P1, in which these steps may be iterated to bring the charging interface 100 to an initial connection position. In this positioning phase P1, the robot-side charging interface 100 makes a relatively large linear travel towards the vehicle 10, ideally without any compliant travel of the compliant component 90a having a value above the noise threshold CN. The positioning phase P1 may consist of an imaging-supported positioning phase P1V and a subsequent blind positioning phase P1B. In the imaging-supported positioning phase P1V, the robot-side charging interface 100 moves from a fully retracted position to a position where the imaging detector 130 can no longer clearly identify the vehicle-side charging interface 20 due to the presence of the proximity part of the robot 50, 250, 350.

[0109] In the sixth step 360, the rotary actuator 53, 55, 57, 59 or the motor 383 is powered individually while its rotational position is controlled to bring the robot-side charging interface 100 from the initial connection position as Figure 5A shown to the correct final engagement position of the robot-side charging interface 100 relative to the vehicle-side charging interface 20 as Figure 5B shown. After the charging interfaces 20, 100 are correctly engaged, the remote lock is activated to lock the engagement. The sixth step 360 forms part of the connection phase P2. Mathematically, the coordinate system C of the robot-side charging interface 100 is collocated with the coordinate system S of the vehicle-side charging interface 20.

[0110] During the connection phase P2, some compliance is expected as a compressive force is required to overcome friction and correctly insert the robot-side charging interface 100 into the mating vehicle-side charging interface 20. During the connection phase P2, some difference may occur between the values of the first compliance CW1 and the second compliance CW2, from which a correctable misalignment results and its correction is caused or detected, which is determined by the connection instruction. For example, the first physical contact 200 as Figure 5C shown may force the robot-side charging interface 100 to tilt or slide relative to the vehicle-side charging interface 20 while transmitting a thrust force from the main base 51 via the biasing coil spring 95. When the defined threshold force is exceeded, the coil spring 95 may be compressed, which is monitored by sensors 66, 96, 110. The compliance provided by the separate coil spring 95 may cause the robot-side charging interface 100 to slip in the direction V along the vehicle-side charging interface 20 through its self-searching shape feature, and / or the corrective activation of the electric motor 83 is determined based on the signals of the sensors 66, 96, 110. In Figure 5CAmong them, the shown misalignment includes translation and rotation in the same plane. Obviously, misalignment in any of the six degrees of freedom may occur, and can be detected and corrected by corresponding correction actions of the rotary actuators 53, 54, 56, 59, 383. This is repeated until the proper final engagement position of the robot-side charging interface 100 relative to the vehicle-side charging interface 20 is reached. In this iteration, as Figure 5D the further physical contact 201 shown in can be detected and corrected by causing slippage in the direction W. Due to this iteration, deviations greater than those allowed by the self-searching shape features of the charging interfaces 20, 100 may be compensated. The end of the travel of the robot 50 causes the first compliance C1 and the second compliance C2 to have values corresponding to approximately half of the maximum length of the compliance travel. Thus, in the robots 50, 250 according to the first and second embodiments, the robot-side charging interface 100 can elastically move towards and away from the movable carrier 60, and in the robot 350 according to the third embodiment, the movable carrier 60 can follow the movement of the vehicle-side charging interface 20.

[0111] In the eighth step 380, charging is activated. The eighth step 380 forms part of the charging phase P3. During the charging phase P3, due to the slight movement of the vehicle 10 relative to the robot 50, some changes in the compliance values may occur. The slight movement of the vehicle 10 may be caused by a passenger stepping in or out or the wind acting on the vehicle 10.

[0112] In the tenth step 400, the remote lock is released to unlock the engagement of the charging interfaces 20, 100. The robot-side charging interface 100 is retracted by corresponding driving of the rotary actuators 53, 54, 56, 59 or the motor 383 and is disconnected from the vehicle-side charging interface 20. The tenth step 400 forms part of the disconnection phase P4.

[0113] During the charging phase P3, the first compliance C1 and the second compliance C2 are continuously measured and monitored by means of the (plural) distance sensors 110. During the charging phase P3, any compliance with a value lower than the noise threshold CN is ignored.

[0114] In the above ideal charging cycle, both the first compliance C1 and the second compliance C2 have values that remain below the positioning intervention value CP during the positioning phase PI. During the connection phase P2, both the first compliance C1 and the second compliance C2 have values that remain below the higher connection intervention value CC. During the charging phase P3, the first compliance C1 and the second compliance C2 have values that remain balanced within a first charging intervention value CH1, for example equal to the connection intervention value CC, and a second charging intervention value CH2, for example higher than the positioning intervention value CP and lower than the connection intervention value CC.

[0115] The following will refer toFigures 6A - 6E Discuss some deviation scenarios in which the electronic control system causes specific interventions to provide safe operation of the charging station 1.

[0116] Figure 6B A scenario is shown in which during the positioning phase P1, the first compliance C1 or the second compliance C2 has a value exceeding the positioning intervention value CP. Then it can be inferred that a collision with an unexpected object has occurred, such as a collision with a person standing between the robots 50, 250, 350 and the vehicle 10. Then in the fifth step 350, the rotary actuators 53, 54, 56, 59 or the motor 383 are stopped or actuated to retract the robot-side charging interface 100 to its fully retracted position.

[0117] Figure 6C A scenario is shown in which at the start of the connection phase P2, the first compliance C1 or the second compliance C2 has a value exceeding the connection intervention value CC. Then it is concluded that the robot-side charging interface 100 is accidentally misaligned with the vehicle-side charging interface 20 to the extent that they can no longer be properly connected. The applied compressive force exceeds the allowable insertion force. This can be caused, for example, by an unexpected movement of the vehicle 10 during the connection phase P2. Then in the seventh step 370, the rotary actuators 53, 54, 56, 59 or the motor 383 are actuated to retract the robot-side charging interface 100 towards its fully retracted position or retract it back to the initial connection position.

[0118] Figure 6D A scenario is shown in which there is a large mutual difference between the first compliance C1 and the second compliance C2 at the start of the connection phase P2. Then it is concluded that the robot-side charging interface 100 rotates unexpectedly relative to the vehicle-side charging interface 20. This can be caused, for example, by an unexpected movement of the vehicle 10 during the connection phase P2. Then in the seventh step 370, the rotary actuators 53, 55, 57, 59 or the motor 383 are actuated to retract the robot-side charging interface 100 towards its fully retracted position or retract it back to the initial connection position.

[0119] Figure 6E A scenario is shown in which during the connection phase P2, the first compliance C1 or the second compliance C2 has a value exceeding the connection intervention value CC. For example, this may be caused by a blockage of the connector during the insertion of the robot-side charging interface 100 into the vehicle-side 20. Then in the seventh step 370, the rotary actuators 53, 55, 57, 59 or the motor 383 are actuated to retract the robot-side charging interface 100 towards its fully retracted position or retract it back to the initial connection position.

[0120] Figure 6FShows a scenario during the charging phase P3 where the first compliance C1 or the second compliance C2 has a value exceeding the first charging intervention value CC1 or below the second charging intervention value CC2. This may be caused by a violent movement of the vehicle 10, for example, due to many passengers stepping into the vehicle 10, which pushes the vehicle-side charging interface 20 towards the movable platform 60 to such an extent that the safety absorption limit of the compliance components 90a - 90f is reached. Then in the ninth step 390, the rotary actuators 53, 55, 57, 59 of the robots 50, 250 according to the first embodiment or the second embodiment are actuated to reposition the movable platform 60 relative to the vehicle 10, whereby the first compliance C1 and the second compliance C2 have values that are rebalanced between the first charging intervention value CC1 and the second charging intervention value CC2, or the motor 383 of the robot 350 according to the third embodiment is actuated to rebalance the compliance components 90a - 90f with the same effect.

[0121] In all scenarios, the values of the first compliance C1 and the second compliance C2 are monitored for exceeding the first warning intervention value CW1 by means of the distance sensor 110. The first warning intervention value CW1 is higher than the positioning intervention value CP, the connection intervention value CC, and the first charging intervention value CC1. When the first compliance C1 or the second compliance C2 has a value exceeding the first intervention value CW1, the rotary actuators 53, 54, 56, 59 or the motor 383 immediately stop when active during the positioning phase P1 or the connection phase P2, and during the charging phase P3, the charging current is interrupted. When the first compliance C1 or the second compliance C2 has a value exceeding the first intervention value CW1, a sound alarm or a visual alarm is triggered.

[0122] In all scenarios, the values of the first compliance C1 and the second compliance C2 are monitored for exceeding the second warning intervention value CW2 by means of the end switch 115. The second warning intervention value CW2 is higher than the first warning intervention value CW1. When the first compliance C1 or the second compliance C2 has a value exceeding the first warning intervention value CW2, the rotary actuators 53, 54, 56, 59 or the motor 383 immediately stop when active during the positioning phase P1 or the connection phase P2, and during the charging phase P3, the charging current is interrupted. When the first compliance C1 or the second compliance C2 has a value exceeding the second warning intervention value CW2, a sound alarm or a visual alarm is triggered. When the first compliance C1 or the second compliance C2 has a value exceeding the second warning intervention value CW2, the remote control lock locking the robot-side charging interface 100 and the vehicle-side charging interface 20 is released to allow the charging interfaces 20, 100 to passively disengage from each other, or to actively disengage by correspondingly powering the rotary actuators 53, 54, 56, 59 or the motor.

[0123] In practice, the first positioning intervention value is 50% or less of the first connection intervention value, preferably 25% or less. In the said embodiment, the first charging intervention value CH1 is equal to the charging intervention value CC.

[0124] It should be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. Many variations will be obvious to those skilled in the art from the above discussion, and these variations will still be within the scope of the invention.

Claims

1. A method for controlling a charging infrastructure, the charging infrastructure comprising a charging station for charging a vehicle having a vehicle-side charging interface, - wherein the charging station comprises a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, - wherein the robot comprises a main base, and a displacement mechanism between the main base and the robot-side charging interface for moving the robot-side charging interface relative to the main base with at least three degrees of freedom, - wherein the displacement mechanism comprises at least one actuator configured to apply a displacement between the main base and the robot-side charging interface over a displacement stroke when the actuator is actuated, - wherein the robot comprises a compliance assembly arranged kinematically in series with the actuator between the main base and the robot-side charging interface, - wherein the compliance assembly is configured to provide compliance by elastically absorbing or releasing a displacement between the base frame and the robot-side charging interface over a compliance stroke, - wherein the method sequentially comprises - a positioning phase in which the robot-side charging interface is moved from a retracted position in which the vehicle can enter or leave the charging station to an initial connection position in which the robot-side charging interface is in front of the vehicle-side charging interface, - a connection phase in which the robot-side charging interface establishes a charging connection with the vehicle-side charging interface from the initial connection position, - a charging phase in which the vehicle is charged by a charging current through the robot-side charging interface, and - a disconnection phase in which the robot-side charging interface disengages from the vehicle-side charging interface and retracts towards the retracted position, - wherein in the positioning phase, the actuator is powered according to a positioning command, the compliance is monitored, the compliance value is compared with a positioning intervention value, and the positioning command is changed when the compliance value exceeds the positioning intervention value, and - wherein in the connection phase, the actuator is powered according to a connection command, the compliance is monitored, the compliance value is compared with a connection intervention value, and the connection command is changed when the compliance value exceeds the connection intervention value, - wherein the positioning intervention value is different from the connection intervention value, and the positioning intervention value is less than the connection intervention value.

2. The method according to claim 1, wherein The positioning intervention value is less than 50% of the connection intervention value.

3. The method according to claim 1 or 2, wherein The positioning intervention value is less than 25% of the connection intervention value.

4. The method according to claim 1 or 2, wherein When the compliance value exceeds the positioning intervention value, the positioning command is changed to stop the actuation of the actuator.

5. The method according to claim 1 or 2, wherein When the compliance value exceeds the positioning intervention value, the positioning command is aborted, and the actuator is powered according to a retraction command to retract the robot-side charging interface towards the retracted position.

6. The method according to claim 1 or 2, wherein When the compliance value exceeds the connection intervention value, the connection command is changed to stop the actuation of the actuator.

7. The method according to claim 1 or 2, wherein When the compliance value exceeds the connection intervention value, the connection instruction is aborted, and the actuator is powered according to a retraction instruction to retract the robot-side charging interface towards the retracted position or back to the initial connection position.

8. The method according to claim 1 or 2, wherein, During the charging phase, the actuator is powered according to a charging instruction and the compliance is monitored, wherein the charging instruction defines that the compliance value is brought between a first charging intervention value and a lower second charging intervention value.

9. The method according to claim 8, wherein During the charging phase, the actuator is powered according to the charging instruction at the start of the charging phase, and when the compliance value is between the first charging intervention value and the lower second charging intervention value, the actuator is idle for the remainder of the charging phase.

10. The method according to claim 8, wherein, When the compliance value exceeds the first charging intervention value or is lower than the second charging intervention value, the actuator is powered according to the charging instruction to bring the compliance value between the first charging intervention value and the second charging intervention value.

11. The method according to claim 8, wherein During the positioning phase, during the connection phase and during the charging phase, the actuator can be powered according to an intervention instruction and the compliance value is monitored, wherein the compliance value is compared with a warning intervention value, and when the warning intervention value is exceeded, an intervention instruction is initiated, the intervention instruction being selected from the group comprising: - Interrupting the charging current through the robot-side charging interface; - Triggering an audible alarm; - Triggering a visual alarm; - Communicating the alarm status to the vehicle or a higher-level management system; - Triggering a mechanical break release; and - Retracting the robot-side charging interface from the vehicle-side charging interface.

12. The method according to claim 11, wherein - during the positioning phase, the warning intervention value is higher than the positioning intervention value; - during the connection phase, the warning intervention value is higher than the connection intervention value; and / or - during the charging phase, the warning intervention value is higher than the first charging intervention value or lower than the second charging intervention value, or the warning intervention value has a first warning intervention value higher than the first charging intervention value and a second warning intervention value lower than the second charging intervention value.

13. The method according to claim 1 or 2, wherein The positioning phase comprises the steps of determining the position of the vehicle-side charging interface and determining the initial connection position by adding the cumulative system inaccuracy to the determined position of the vehicle-side charging interface or subtracting the cumulative system inaccuracy from the determined position of the vehicle-side charging interface.

14. The method according to claim 3, wherein, During the charging phase, the actuator is powered according to a charging instruction and the compliance is monitored, wherein the charging instruction defines that the compliance value is brought between a first charging intervention value and a lower second charging intervention value.

15. The method according to claim 1, wherein, During the positioning phase, the robot-side charging interface is aligned with the vehicle-side charging interface.

16. A charging infrastructure, the charging infrastructure comprising a charging station for charging a vehicle having a vehicle-side charging interface, wherein the charging station comprises a robot carrying a robot-side charging interface for establishing a charging connection with the vehicle-side charging interface, wherein the robot comprises a main base, a displacement mechanism between the main base and the robot-side charging interface for moving the robot-side charging interface relative to the main base with at least three degrees of freedom, wherein the displacement mechanism comprises at least one actuator configured to apply a displacement between the main base and the robot-side charging interface over a displacement stroke when the actuator is actuated, wherein the robot comprises a compliance assembly arranged kinematically in series with the actuator between the main base and the robot-side charging interface, wherein the compliance assembly is configured to provide compliance by elastically absorbing or releasing a displacement between the base frame and the robot-side charging interface over a compliance stroke, wherein the charging infrastructure further comprises a controller operatively connected to at least the robot and configured to perform the method according to any one of claims 1 to 15.

17. The charging infrastructure according to claim 16, wherein, The controller is an electronic controller configured to determine a resultant force and / or resultant moment acting on the robot-side charging interface based on the compliance stroke and / or the compliance stroke in one direction (L) of the applied individual or combined compliance assemblies.

18. The charging infrastructure according to claim 16 or 17, the charging infrastructure comprising a sensor between a carrier and the charging interface to obtain or derive compliance data in six degrees of freedom, the sensor being a distance sensor and / or a force or pressure sensor with respect to the compliance stroke.

19. The charging infrastructure according to claim 16 or 17, the charging infrastructure comprising a switch, the switch being an end switch positioned and configured to detect the abutment of an end stop, and / or positioned and configured to serve as part of a redundant control system to ultimately intervene or override the main control system in an extreme situation detected by the end switch.

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