Patent ID: 12214685

DETAILED DESCRIPTION

FIGS.1,2A and2Bshow a charging station1with a vehicle area2for electrically charging an electrically powered vehicle10, in this example a passenger car. The vehicle10may be fully electrically powered or it may have a hybrid drive in which an electric drive is combined with fuel combustion. The vehicle10has a vehicle body11on wheels12and a vehicle-side charging interface20carried by the vehicle body11, in this example on the right side of the vehicle body11above one of the rear wheels12.

The specific pinout of the vehicle-side charging interface20may be of any known type, such as the so called Mennekes, Yazaki, Schuko or Combo type. As shown inFIGS.2B and5A, the vehicle-side charging interface20is in this example a Combo CCS-2 inlet that accepts both normal charging and high speed charging. The vehicle-side charging interface20comprises a front surface21that merges inwardly into a circumferential inner surface22. The inner surface22merges into a bottom surface23from which a first socket24and a second socket31project. The first socket24comprises a socket body25of electrically isolating material having five first channels26in which five recessed normal charging connectors27extend, and two second channels28in which in two control connectors29extend. The second socket31comprises a socket body31of electrically insulating material having two third channels32in which two high speed charging connectors33extend. The inner surface21and the socket bodies26together define a slot30around the sockets24,31. The slot30, the first channels26, the second channels28and the third channels32have a receiving direction R parallel to the first channels26, the second channels28and the third channels32.

As shown inFIG.3, the charging station1comprises a robot50having a robot-side charging interface100for establishing a charging connection with the vehicle-side charging interface20. The robot-side charging interface100is electrically connected with a not shown battery charger. The robot50comprises a schematically illustrated main base51that is in this example supported by a console3aside the vehicle area2at the side close to the vehicle-side charging interface20. The robot50can be positioned at any side, or at the front side or at the back side of the vehicle10depending on the location of the vehicle-side charging interface20. Alternatively the robot50is positioned on or under the floor to reach a vehicle-side charging interface20at the bottom side of the vehicle10, or the robot50is suspended above the vehicle10to reach a vehicle-side charging interface20at the top side or on the roof of the vehicle10.

The main base51comprises a main frame52and two first leg supports53, two second leg supports54and two third leg support55on the main frame52that are in a same plane and that form pairs in a triangular configuration.

As best shown inFIGS.2B and3, the robot50comprises a moveable carrier60having a carrier frame61and two first leg supports62, two second leg supports63and two third leg supports64on the carrier frame61that are in a same plane and that form pairs in a triangular configuration, wherein the distances between the pairs are smaller than the distances between the pairs of leg supports53-55of the main base51. The carrier60carries the robot-side charging interface100.

As shown inFIGS.2B,3and5A, the robot-side charging interface100is in this example of the so called Mennekes type (type 2 connector under IEC 62196) for normal charging. The robot-side charging interface comprises a shield101that mates with and fits inside the slot30of the vehicle-side charging interface20, and multiple first bushes102and second bushes103that mate with and fit inside the respective first channels26and second channels28of the vehicle-side charging interface20. The robot-side charging interface100comprises charging connectors that are recessed inside the bushes102,103and that electrically connect with the connectors27,29of the vehicle-side charging interface20. The shield101, the first bushes102and the second bushes103have an insert direction P parallel therewith. The insert direction P is by default perfectly parallel to and aligned with the receiving direction R of the vehicle-side charging interface20.

The vehicle-side charging interface20and the robot-side charging interface100typically have a very precisely fitting geometry that allow at the initial mutual contact only a slight misalignment transverse to the receiving direction R of about maximal 3 millimeters, or a slight misalignment of maximal 10 degrees when manually plugged into each other. Due to the self-searching shape features of the charging interfaces20,100such misalignments are automatically corrected, whereby the charging interface20,100come into proper mutual engagement. The connectors27,29,33of the vehicle-side charging interfaces20and the connectors of the robot-side charging interface may have different lengths or positions in the insert direction P and receiving direction R to impose a default contact sequence between the mating connectors, even when they are misaligned. This ensures for example that a ground connection or a control connection is established before the power connections are made.

The robot50comprises in this example in total six displacement assemblies between the main base51and the moveable carrier60that are embodied as six legs71-76that extend between the leg supports53-55of the main base51and the leg supports62-64of the moveable carrier60to form a hexapod mechanism70between the main base51and the moveable carrier60. The legs71-76are identical in construction and are hereafter described in detail by referring to the second leg72. Details thereof are also shown inFIG.4.

The second leg72comprises a rectilinear motion actuator80having an outer tube81that is at its bottom end connected to its leg support53-55of the main base51via a first coupling88that is embodied as a universal joint. The rectilinear motion actuator80has in this example an electric motor83that is mounted to the outer tube81. The rectilinear motion actuator80has a drive rod82that is rectilinearly guided inside the outer tube81and that partly projects from the outer tube81. The drive rod82is operatively connected with the electric motor83, for example via a spindle. The drive rod82is thereby reciprocally rectilinearly moveable in direction A with respect to the first coupling88over a displacement stroke by powering the electric motor83accordingly. The rectilinear motion actuator80has an internal first sensor to measure the position of the drive rod82with respect to the outer tube81, such as a revolution sensor or a revolution counter on the spindle. Thereby each leg71-76has such first sensor.

The second leg72comprises a compliance assembly90in series with the rectilinear motion actuator80. The compliance assembly90comprises in this example an outer tube91that is mounted to the end of the drive rod82of the rectilinear motion actuator80, and a connecting rod92that is rectilinearly guided inside the outer tube91, in this example by means of a slide bearing93. The connecting rod92partly projects from the outer tube91and the compliance assembly90comprises an end stop94at the end of the connecting rod92that remains behind the slide bearing93to determine a defined outermost position of the connecting rod92with respect to the drive rod82, and a reversible flexible element, in this example a spring, in particular a coil spring95between the end stop94and the drive rod82that is biased to keep the end stop94in abutment with the slide bearing93. By means of the coil spring95the connecting rod92can resiliently slide back in direction B towards the drive rod82over a compliance stroke when a defined threshold force is exceeded that overcomes the bias. The connecting rod92is at its distal end connected to its leg support61-63of the moveable carrier60via a second coupling89that is embodied as a universal joint.

The length of the compliance stroke is minimal 1 millimeter and maximal 100% of the maximum length of the displacement stroke of the drive rod82.

In de described embodiment the compliance assembly90is biased to and against the end stop94. Alternatively, the coil spring95or any other resilient element provides resilience in opposite directions with or without implementing a threshold force whereby the connecting rod92can resiliently be pushed towards and pulled away from the drive rod82. The coil springs95in the individual legs71-76may have different impedances, in this example different stiffness to ensure a default position of the robot-side charging interface100without hanging down due to for example an uneven weight distribution following from the different individual weights of the various components present in the robot50.

The six legs71-76form in this example a hexapod mechanism70between the main base51and the moveable carrier60. Alternatively formulated the six legs71-76form a Stewart-platform. The rectilinear motion actuators80impose displacements between the first couplings88and second couplings89which are directly followed by the moveable carrier60as long as the threshold forces on the compliance assemblies90are not exceeded. The moveable carrier60can thereby make translations in the three orthogonal directions X, Y, Z (lateral, longitudinal and vertical) and make rotations around these axes (pitch, roll, yaw), in total six degrees of freedom (6-DOF). A part of the imposed displacements between the first couplings88and the second couplings89can be reversibly absorbed by the compliance assemblies90when the threshold force is exceeded.

The compliance assembly90has an internal second sensor96to measure the position of the connecting rod92with respect to the drive rod82, such as a distance sensor, or a pressure sensor or force sensor to measure the pressure force that the connecting rod92exerts onto the drive rod82. Thereby each leg71-76has such second sensor96whereby compliance data can be obtained that is related to the compliance between the moveable carrier60and the drive rods75at the actual position of the moveable carrier60as obtained with the first sensors.

This compliance comprises translations in the three orthogonal directions X, Y, Z (lateral, longitudinal and vertical) and rotations around these axes (pitch, roll, yaw), in total six degrees of freedom (6-DOF). Alternatively or in addition thereto, the moveable carrier60comprises a third sensor66between the carrier frame61and the robot-side charging interface100, such as a pressure sensor matrix, to obtain or derive abovementioned compliance data in the six degrees of freedom.

The charging station1comprises an electronic control system for controlling the operation of the charging station1. The control system comprises one or more imaging detectors130, such as a video camera or multiple cameras to form a stereo camera, or distance sensors such as a LIDAR, radar or led based sensors to detect the position of the vehicle-side charging interface20of the vehicle in the charging station1. The imaging detectors130form therefore part of a vision system. The imaging detectors130may be base-mounted, such as on the console3as shown, or be carried by the robot50, such as on the carrier frame61as shown. The control system comprises an electronic controller that is connected with the electric motors83to power their rotation. The electronic controller is connected with the detectors130, and with the first sensors of the linear actuators80and the second sensors96of the compliance assemblies90and/or with the third sensor66between the carrier frame61and the robot-side charging interface100.

The charging station forms part of a charging infrastructure having a remote computer server for communication with and for configuration of the electronic controller. The electronic controller is loaded with software that is executed by a processor of the electronic controller, whereby the charging station1performs the following operation as schematically indicated inFIG.6. The explanation starts with fully retracted drive rods82of the legs71-76whereby the robot-side charging interface100is withdrawn from the vehicle area2in a standby position to allow the vehicle10to enter the charging station1.

In a first step310the presence of a particular vehicle10at the vehicle area2is notified by means of the imaging detectors130, or by any other appropriate sensor, or by any type of data communication between the vehicle10and the charging station1, or by any type of remote trigger system, or by registration by the driver of the vehicle10, or by a human operator on site at the charging station1.

When the presence of the vehicle10is notified, then in a second step320the spatial position and orientation of the vehicle-side charging interface20in the charging station1are determined by means of the imaging sensors130. This comprises the position in the three orthogonal directions X, Y, Z and any rotational orientation around these axes.

In a third step330, the corresponding particular initial spatial position and orientation of the robot-side charging interface100are determined in which the robot-side charging interface100can be correctly inserted in direction R into the vehicle-side charging interface20as shown inFIG.5A.

In a fourth step340, the electric motors83are individually powered while controlling the individual positions of the drive rods82in direction A with the first sensors to bring the robot-side charging interface100in the particular initial spatial position and orientation. In this fourth step340the individual positions of the connecting rods92with respect to the drive rods82or any forces acting between the connecting rod92and the drive rod82are monitored by means of the second sensors96. Alternatively or in addition thereto this can be determined with the third sensor66. The movements are monitored with the vision system as formed with the imaging detectors130. When any one of the connecting rods92is displaced towards the driving rod75of the same leg71-76, it is assumed that an unexpected physical contact has occurred, for example a collision with a foreign object, such as a human, a vehicle or any other surrounding. Then in a fifth step350the electric motors83are stopped or reversed to retract the robot-side charging interface100.

When no collision has occurred, then in a sixth step360following the fourth step340, the electric motors83are powered while controlling the positions of the drive rods82in direction A with the first sensors to push the robot-side charging interface100into the vehicle-side charging interface20. In the sixth step360the positions of the connecting rods92with respect to the drive rods75are monitored by means of the second sensors96or determined by means of the third sensor66to execute three functions:

The first function is the determination of the proper final engagement position of the robot-side charging interface100with respect to the vehicle-side charging interface20as shown inFIG.5B. The final engagement is obtained by exercising a pushing force in the insert direction P. This pushing force is transferred from the main base51to the movable carrier60via the biased coil springs95. The coil springs95may be pushed in when their defined threshold force is exceeded, which is monitored by means of the second sensors96or the third sensor66. In the first function this compliance in the legs71-76is at least partly compensated by accordingly powering the electric motors83in order to be able to reach the proper final engagement position of the robot-side charging interface100with respect to the vehicle-side charging interface20. The proper final engagement may be confirmed by the battery charger that is connected to the robot-side charging interface100.

The second function is the determination of an unexpected physical contact between the robot-side charging interface100and the vehicle-side charging interface20.

The third function is the determination of an acceptable misalignment of the robot-side charging interface100with respect to the vehicle-side charging interface20, such as for example shown inFIG.5C, due to an expected or unexpected first physical contact200. This first physical contact200forces the robot-side charging interface100to tilt or slide with respect to the vehicle-side charging interface20while a pushing force is transferred from the main base51to the movable carrier60via the biased coil springs95. The coil springs95may be pushed in when their defined threshold force is exceeded, which is monitored by means of the second sensors96or the third sensor66. The compliance as provided by the individual coil springs95may induce a sliding movement of the robot-side charging interface100in direction V along the vehicle-side charging interface20by their self-searching shape features, and/or a corrective activation of the electric motors83is determined based on the signals of the second sensors96or third sensor66. InFIG.5Cthe illustrated misalignment contains a translation and a rotation in the same plane. It will be clear that any misalignment in all six degrees of freedom can occur, can be detected and corrected by corresponding corrective actions of the electric motors83. This is repeated until the proper final engagement position of the robot-side charging interface100with respect to the vehicle-side charging interface20is reached. In this iteration a further physical contact201as shown inFIG.5Dmay be detected and corrected by inducing a sliding movement in direction W. The electronic control system may monitor the electrical connections with theconnectors of the robot-side charging interface, for example via the battery charger, to determine a misalignment, for example by determining a contact sequence or by detecting any deviations from the default contact sequence.

In an seventh step370, the engaged robot-side charging interface100and vehicle-side charging interface20are locked to prevent disengagement, and the vehicle2is charged via the properly engaged charging interfaces20,100.

After charging, the charging interfaces20,100are unlocked and robot-side charging interface100is disengaged from the vehicle-side charging interface20in an eighth step380by retracting the drive rods82of the legs71-76. The drive rods82are fully retracted to retract the robot-side charging interface100to said standby position.

The specific compliance as provided by the parallel compliance assemblies90has the following advantages:

Firstly, the compliance enables safe detection of any expected or unexpected physical contact, for example a collision with a human, when the robot-side charging interface100is moved into its initial spatial position with respect to the vehicle-side charging interface20. The compliance provides softness or flexibility when hitting the robot-side charging interface100.

Secondly, the compliance allows the detection of any misalignment between the robot-side charging interface100and the vehicle-side charging interface20after the initial spatial position and orientation have been reached. The misalignment is derived from the detected physical contact. The compliance facilitates to rapidly obtain the proper final engagement position using the self searching shape features of the robot-side charging interface100and vehicle-side interface20. The compliance makes the physical contact itself safer as damaging peak forces are prevented by the provided resilience or compliance.

Thirdly, the compliance facilitates the disengagement of the robot-side charging interface100from the vehicle-side charging interface20, in particular when the position of the vehicle10has changed during the charging process.

Fourthly, the compliance absorbs any rigid motion as imposed by the rectilinear motion actuators80or by small movements of the vehicle10. These small movements may be caused for example by passengers that step in or out of the vehicle2, or by wind acting against the vehicle2.

The compliance assemblies90therefore provide tactile feedback in the six degrees of freedom of movement of the moveable carrier60and therefore from the vehicle-side charging interface100. This tactile feedback is derived from the third sensor66or the second sensor96and it is used by the electronic controller in controlling the rectilinear movement actuators80. The vision system provides visual feedback.

It is to 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. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.