DE102020111332A1 - Charging robot for an electric vehicle - Google Patents

Abstract

A charging robot (10) for an electric vehicle (50) is described which has a manipulator (12, 13, 14, 15, 16, 17, 18) with an end effector (20), the end effector (20) having a charging connector (45 ) or means (20) for gripping a charging plug (45), a controller (30) which is set up to control movements of the manipulator (12, 13, 14, 15, 16, 17, 18), and means ( 25) for measuring instantaneous values of forces and / or moments which act on the charging plug (45) from outside, the controller (20) being set up to calculate a compensating movement as a function of the measured instantaneous values and to control the manipulator ( 12, 13, 14, 15, 16, 17, 18) according to the calculated compensation movement.

Description

TECHNICAL AREA

The present disclosure relates to a charging robot for an electric vehicle with which electric energy storage devices of electric vehicles can be charged with electricity.

BACKGROUND

More and more vehicle owners are switching from vehicles with internal combustion engines to electric vehicles. The number of charging stations for electric vehicles is increasing accordingly. In contrast to petrol pumps at gas stations, the charging stations are often located in the open air, which makes charging unattractive, especially in bad weather. To charge the vehicle, the driver has to get out of the electric vehicle, connect a charging cable to the charging station and plug the charging plug of the charging cable into the charging socket of the electric vehicle. At the end of the charging process, he has to pull the charging plug of the charging cable out of the charging socket of the vehicle and disconnect the charging cable from the charging station.

Charging robots can relieve the vehicle driver of such a manual charging process. The pamphlet WO 2016/096194 A1 discloses, for example, a device and a method for automatically charging an electrical energy storage device in a vehicle in which a charging robot drives on the floor near the charging socket of the vehicle and the charging robot then establishes an electrical connection between the charging station and the charging socket for charging the electrical energy storage device.

However, since the charging robots, like the charging station, are often set up in the open air, the electrical plug connections and plug contacts of the charging plugs and charging sockets are exposed to the weather and moisture. This is particularly disadvantageous because the electrical plug connections and plug contacts of the charging plugs and charging sockets are mechanically stressed during each insertion and removal process between the charging plug and the charging socket. The service life of charging plugs and charging sockets can be reduced by wear and tear if the charging plug is not inserted straight into the charging socket or if the charging plug is not pulled out of the charging socket with even force in the right direction.

SHORT SUMMARY

The present disclosure is based on the object of providing a charging robot for an electric vehicle which contributes to reducing the wear and tear on charging plugs of charging cables and charging sockets in electric vehicles.

According to a first aspect of the present disclosure, a charging robot for an electric vehicle is proposed, which has a manipulator with an end effector, the end effector comprising a charging plug or means for gripping a charging plug, a controller which is configured to control movements of the manipulator, and Means for measuring instantaneous values of forces and / or moments that act on the charging plug from the outside, wherein the controller is set up to calculate a compensation movement as a function of the measured momentary values and to control the manipulator according to the calculated compensation movement.

The loading robot can be, for example, an industrial robot with a manipulator with six degrees of freedom. The manipulator can include further elements such as a base, axes with drive units (motors, gears, angle encoders), connecting elements for a structural design and mechanical coupling of the axes, cables or lines for power supply, control and signal transmission, and a housing. The end effector is arranged at the distal end of the manipulator and is also referred to as a tool center point (TCP).

The charging plug can, for example, be a type 1 plug, type 2 plug, type 3 plug, Combined Charging System (CCS) plug, CHAdeMO plug or Tesla Supercharger plug (trademark). Correspondingly, the means for gripping a charging plug can be a gripper that can reliably grip a charging plug of a charging station and plug the charging plug into a charging socket of an electric vehicle and pull it out of it.

The control can be hardware and software, in particular a microprocessor with memory and control software running on it, which controls movements of the manipulator, for example according to a point-to-point control (PTP), a four-point control or a path control.

The means for measuring instantaneous values of forces and / or moments that act from the outside on the charging plug can include, for example, a direct force measurement, a six-axis force / moment sensor or a force estimation, and can be set up to measure any contact forces and / or or moments that act from the outside on the charging plug and / or the end effector to measure in real time and these measured values forward to the controller. In the case of a force estimation, the measured value here means the estimated value.

The control processes the received measured values and takes them into account when controlling the movement of the manipulator. In particular, the controller is set up to calculate a compensation movement as a function of the measured instantaneous values and to control the manipulator in accordance with the calculated compensation movement.

If the electric vehicle is charged or discharged, the height of the charging socket of the electric vehicle relative to the floor is increased or decreased. The difference in height between a loaded electric vehicle and an unloaded electric vehicle can be several centimeters. This can lead to damage to the charging robot or to the electrical contacts of the charging plug and the charging socket if the electric vehicle is lowered or raised while the charging plug is in the charging socket, as the manipulator is usually not moved while the electric vehicle is charging . To avoid such wear and tear, the controller can be set up to control the manipulator in accordance with the calculated compensating movement while the charging plug is fully inserted into a charging socket of an electric vehicle. Whether the charging plug is fully inserted into the charging socket can be determined by a test current flowing due to the electrical connection between the charging plug and the charging socket.

If, for example, the electric vehicle is loaded with a large number of heavy packages during an electricity charging process, this is recognized by the contact force measurements. The calculated compensatory movements then compensate for the lowering of the electric vehicle in real time. The end effector is lowered in real time in accordance with the lowering of the electric vehicle. Corresponding compensatory movements can be made for lifting the charging socket relative to the floor. Lateral movements or combinations of lateral and upward and downward movements of the charging socket (for example, if the electric vehicle swings slightly due to a package thrown into the trunk) can be compensated for by the calculated compensation movements. In particular, the compensatory movements can take place in all spatial directions. Mechanical stress on charging plugs and charging sockets and the electrical contact elements arranged therein can thus be reduced.

A critical moment for the mechanical stress on the charging plug and charging socket is the insertion of the charging plug into the charging socket, since during this process the electrical contacts of the charging plug and the charging socket slide against each other. The aim is to keep the mechanical resistance as low as possible when sliding, i.e. to insert the charging plug as straight as possible into the charging socket. However, problems can arise if the height of the charging socket changes with respect to the floor during the insertion process, for example due to loading or unloading of the electric vehicle. Similar problems can arise if the charging plug is pulled out of the charging socket while the electric vehicle is being charged or discharged. To avoid such problems, the controller can be set up to control the manipulator in accordance with the calculated compensating movement while the charging plug is plugged into and / or removed from a charging socket of an electric vehicle.

To reduce the wear and tear of the electrical contacts of the charging plug and charging socket, the manipulator can have a plurality of segments connected via joints, the joints comprising at least one elastic joint and / or the plurality of segments comprising at least one elastic segment. In particular, flexible mounting of the axes of the loading robot can be provided. The elastic joints or elastic segments prevent tilting between the charging plug and charging socket when plugging in and unplugging. In addition, excessive wear and tear on the electrical contact elements of the charging plug and charging socket in an assembled state is avoided. To avoid undesirable vibration behavior of the loading robot due to the flexible mounting, i.e. the elastic joints or elastic segments, the control can be based on a robot movement model with equations of motion for elastic robots, which includes, among other things, an inertia matrix.

In a preferred embodiment, the means for measuring instantaneous values of forces and / or moments which act on the charging plug from the outside comprise a force / moment sensor. A six-axis force / torque sensor is preferably used. To avoid vibrations in the manipulator, in particular when loading and unloading the electric vehicle, the force / torque sensor can be arranged in a joint of the manipulator.

Force / moment sensors are not only very sensitive to overload but also to moisture. Since charging robots are often set up in the open air and wind and Are exposed to weather, the charging robot can, in addition to a conventional housing, comprise a cover which surrounds the joint in which the force / moment sensor is arranged, seals the joint in a watertight manner and is made of a flexible material. The cover can for example be designed like a hose and consist of polyvinyl chloride (PVC). Shrink tubing can also be used for easy assembly.

The charging robot can further comprise means for determining whether the electric vehicle is a fleet vehicle. Fleet vehicles in the sense of this disclosure are the same electric vehicles with the same height of the charging socket above the ground with the same load. The means for determining whether the electric vehicle is a fleet vehicle can be, for example, a radio frequency identification (RFID) reader which is set up to read RFID tags attached to each electric vehicle in the fleet. The RFID tags store a unique identifier which enables the controller connected to the RFID reader to determine whether the electric vehicle is a fleet vehicle. Other wireless communication solutions such as Bluetooth are also conceivable.

A fleet of electric vehicles can, for example, consist of 50 Mercedes-Benz eVito Tourer Pro (trademark) from a parcel delivery service, in which all fleet vehicles are always completely unloaded from the freight and charged with electricity after one working day. In this case, the controller knows the height of the charging socket above the ground (for example, it has been programmed in beforehand) and the controller can accordingly calculate an approximate spatial starting position for a linear insertion movement of the charging plug into the charging socket depending on the known height. The exact position and orientation (six degrees of freedom) at the start of the movement must also be recorded, for example by sensors. Nevertheless, on the one hand, this saves time for determining the spatial insertion start position, which leads to a shortening of the loading time. On the other hand, the linear insertion movement reduces the mechanical resistance between the electrical contact elements of the charging socket and the charging plug, which reduces wear on the electrical contact elements. In particular, "shaking" the charging plug into the charging socket can be avoided. Thus, for the simplified and resource-saving insertion of the charging plug into the charging socket, the controller can be set up to control the manipulator as a function of the determination of whether it is a fleet vehicle. In particular, after determining that the electric vehicle to be charged is a fleet vehicle, the height of the charging socket above the ground or the position and orientation of the charging socket in relation to a spatially fixed coordinate system is used in the calculation of the approximate spatial starting position of a linear insertion movement of the Charging plug into the charging socket. Consequently, computing power can also be saved in this training. The known height of the charging socket above the ground can also be used for a verification of calculated spatial position data of the charging socket.

The charging robot can furthermore comprise means for determining a vehicle type of an electric vehicle to be charged. The means for determining a vehicle type of an electric vehicle to be charged can be, for example, a camera that records an image of the electric vehicle to be charged. The recorded image is then compared with vehicle images stored in a database and the vehicle type is determined. This determination can be made with the help of an artificial intelligence (AI) -based comparison algorithm. The comparison algorithm can be executed in the control of the loading robot. However, it is also conceivable that the charging robot sends the recorded image via the Internet to an external server, which executes the comparison algorithm and sends the specific vehicle type to the controller of the charging robot. Furthermore, the camera can record the license plate of the electric vehicle, which is then compared with license plates stored in a database.

The controller can also be set up to determine, with the aid of the determined vehicle type, a maximum payload of the electric vehicle to be charged and / or a height of the charging socket above the floor of the electric vehicle to be charged. In particular, it can be determined from the maximum load of the electric vehicle to be charged how the height of the charging socket above the ground differs between an unloaded electric vehicle and a fully charged electric vehicle. The determination of the maximum load of the electric vehicle to be charged, the height of the charging socket above the floor of the electric vehicle to be charged and the difference in height of the charging socket between non-load and full load of the electric vehicle to be charged can also be done in an external server, with the results being sent to the controller via the Internet of the loading robot.

The controller can also be set up to control the manipulator as a function of the maximum payload and / or the height of the charging socket above the floor of the electric vehicle to be charged. So can the controller For example, when controlling the manipulator, take into account maximum values of the compensatory movements of the manipulator, which correspond to the maximum height and the minimum height of the charging socket above the ground.

Figure list

• 1 zeigt eine schematische Ansicht eines Ausführungsbeispiels eines Laderoboters für ein Elektrofahrzeug mit einer Ladestation und einem zu ladenden Elektrofahrzeug; und
• 2 zeigt eine schematische Ansicht eines Ausführungsbeispiels einer Steuerung eines Laderoboters.

Further advantages, details and features of the devices and systems described here emerge from the following description of exemplary embodiments and from the figures.

• 1 shows a schematic view of an embodiment of a charging robot for an electric vehicle with a charging station and an electric vehicle to be charged; and
• 2 shows a schematic view of an embodiment of a control of a loading robot.

DETAILED DESCRIPTION

the 1 shows a schematic view of an embodiment of a charging robot for an electric vehicle with a charging station and an electric vehicle to be charged.

In the embodiment of 1 is the loading robot 10 for example designed as an industrial robot with a manipulator. Other types of robots are also conceivable. The manipulator comprises a kinematic chain consisting of joints 12th , 14th , 16 and 18th and segments arranged therebetween 13th , 15th and 17th . At the distal end of the manipulator is an end effector 20th arranged, which in the embodiment of 1 as a gripper 20th is trained. For the sake of clarity, the 1 additional elements of the loading robot 10 , such as motors, gears, angle encoders, sensors, etc., not shown.

The loading robot 10 has several axes of rotation or thrust (rotary or translational axes), which can be superimposed by combining the individual movements to form an overall movement. On the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th of the loading robot 10 arrows are shown, which possible directions of rotation of the joints 12th , 14th , 16 and 18th illustrate.

The loading robot 10 includes a controller 30th that have a cable 31 with the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th connected is. The control 30th is set up for movements of the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th to control.

Furthermore, the charging robot includes 10 a six-axis force / torque sensor 25th for measuring instantaneous values of an externally applied contact force and / or an acting moment. The six-axis force / torque sensor 25th is between gripper 20th and joint 18th arranged. The control 30th is set up to calculate a compensation movement as a function of the measured instantaneous values and the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th to be controlled according to the calculated compensation movement.

the 1 also shows a charging station 40 with a charging cable 43 and a charging plug 45 . The charging plug 45 has electrical contact pins 47 on.

Furthermore, in the embodiment of the 1 an electric vehicle 50 shown which a charging socket 52 and a flap 57 to close the charging socket 52 having. The flap 57 can, for example, open automatically as soon as the charging plug is inserted 45 comes near them. The charging socket 52 has electrical contacts 55 on which to the electrical contact pins 47 of the charging plug 45 fit. Furthermore is on the electric vehicle 50 an RFID tag 60 appropriate.

The gripper 20th is set up to use the charging plug 45 to grab it and put it in the charging socket 52 to plug that in the contact pins 47 galvanically with the contacts 55 be coupled. This process is described as the plug-in process in the present disclosure. Accordingly, there is a state in which the electric vehicle 50 is charged with electricity when the charging plug 45 into the charging socket 52 was plugged. After the charging process is finished, the charging plug 45 from the charging socket 52 pulled, which happens after the end of the charging process.

In the embodiment of 1 is the gripper 20th designed in such a way that it has the charging plug 45 can grab. Other recording techniques, such as magnets, can also be used. Alternatively, it is conceivable that the charging plug 45 integral with the loading robot 10 as an end effector 20th is trained.

The following is a control of the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th through the controller 30th described during the charging plug 45 into the charging socket 52 of the electric vehicle 50 is plugged.

The control 30th controls the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th such that the gripper 20th the plug 45 grips and then moved to a spatial position from which the connector 45 in a linear motion into the charging socket 52 can be plugged. When inserting the charging plug 45 into the charging socket 52 the six-axis force / torque sensor measures 25th in real time through the Insertion process on the charging plug 45 acting contact forces. These measurement results are taken from the control 30th processed in real time. The control 30th calculates corresponding compensatory movements, so that the charging plug 45 into the charging socket with the lowest possible mechanical resistance 52 can be plugged. In particular, compensatory movements of this kind are calculated and implemented, even when the electric vehicle is being charged 50 while the charging plug is being inserted 45 into the charging socket 52 Lowering or raising of the charging plug 45 above the ground 90 be balanced. Corresponding compensatory movements can also be made when the charging socket is displaced to the side 52 take place. The control is accordingly 30th set up the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th according to the calculated compensation movement to be controlled during the charging plug 45 into the charging socket 52 of the electric vehicle 50 is plugged.

The following is a control of the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th through the controller 30th described when the charging plug 45 in the charging socket 52 of the electric vehicle 50 is located. Corresponding to the compensatory movements described above when inserting the charging plug 45 into the charging socket 52 will also be in the state in which the charging plug is 45 in the charging socket 52 is located by the six-axis force / torque sensor 25th determines in real time whether contact forces are exerted on the charging plug 45 works. In particular, it is determined whether the position and orientation of the charging socket 52 based on a spatially fixed coordinate system (above the ground 90 ) changes. In this case, appropriate compensatory movements are made by the control 30th calculated and the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th controlled accordingly. The control 30th is thus set up to use the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th according to the calculated compensation movement to be controlled during the charging plug 45 completely into the charging socket 52 of the electric vehicle 50 is plugged in.

The following is a control of the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th through the controller 30th described when the charging plug 45 from the charging socket 52 of the electric vehicle 50 is pulled. Similar to the insertion process, the six-axis force / torque sensor measures 25th when unplugging in real time on the charging plug 45 acting contact forces. These are controlled by the controller 30th processed and corresponding compensatory movements calculated. So is the control 30th set up the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th according to the calculated compensation movement to be controlled during the charging plug 45 from the charging socket 52 of the electric vehicle 50 is pulled.

To change the position and orientation of the charging socket 52 in relation to a spatially fixed coordinate system (in relation to the ground 90 ) it is also possible to balance the joints 12th , 14th , 16 , 18th comprise at least one elastic joint and / or the segments 13th , 15th , 17th comprise at least one elastic segment. Additional compensatory movements can take place through the elastic joints or elastic segments. A flexible mounting of the axes of the loading robot is also possible. The control 30th takes this flexibility into account in the robot control model.

About vibrations in the charging robot 10 to avoid that due to different loads of the electric vehicle 50 and the contact between the charging plug and the electric vehicle 50 result, the six-axis force / torque sensor 25th in a joint 12th , 14th , 16 , 18th of the manipulator 12th , 13th , 14th , 15th , 16 , 17th , 18th be arranged.

In the 1 is also an example of a cover 28 at the joint 16 shown. The cover 28 is provided in addition to a standard robot housing and provides protection against external moisture. In the 1 is the six-axis force / torque sensor 25th for example at the end effector 20th arranged. In a further embodiment, the six-axis force / torque sensor 25th also in the joint 16 be arranged. In this case the cover has 28 a particularly beneficial effect because it uses the six-axis force / torque sensor 25th protects against external weather-related influences such as moisture and wind.

the 2 shows a schematic view of an embodiment of a controller 30th a loading robot 10 . In particular, it is in the 2 control shown 30th around the in the 1 control shown 30th .

The control 30th includes an RFID reader 32 , a camera 34 and a communication device 36 .

The RFID reader 32 is set up to receive data from an RFID tag 60 to recieve. The RFID tag 60 is on an electric vehicle 50 attached (see 1 ) and saves a unique identifier, which it controls 30th allows you to see whether it is in the electric vehicle 50 is an electric vehicle of a certain vehicle fleet.

It is found that it is the electric vehicle 50 If it is an electric vehicle of a certain vehicle fleet, the control recognizes or can the control 30th determine the height of the charging socket 52 in an unloaded state of the electric vehicle 50 above the ground 90 has or which relative position (six degrees of freedom) the charging socket 52 based on the position of the electric vehicle 50 having. With the help of this data, the controller 30th determine from which spatial starting position the charging plug 45 in a linear movement into the charging socket 52 must be plugged in, so that the lowest possible mechanical stress on the electrical contacts 47 and 55 of the charging plug 45 and the charging socket 52 he follows.

The camera 34 is set up to take a digital photo of the electric vehicle 50 to record. Using the photo of the electric vehicle 50 it can be determined what type of vehicle it is and what maximum load of the electric vehicle is 50 is possible. This can be used to determine the minimum height (full load) and the maximum height (no load) of the charging socket 52 above the ground 90 to be determined.

The communication device 36 is on the internet 70 with a server 80 tied together. Data of the loading robot 10 , for example that from the camera 34 captured photo, can be accessed through the Internet 70 to the server 80 be sent. The server 80 can be set up to process received data. For example, the vehicle type of the electric vehicle can be in the server 50 , the maximum load on the electric vehicle 50 and / or the maximum and minimum height of the charging socket 52 above the ground 90 determined and on the internet 70 to the communication device 36 be sent. In the control 30th this data can then flow into the calculation of the compensation movement. Alternatively, it is conceivable that all data processing and calculations in the control 30th take place.

Thus, advantageous techniques for a charging robot are disclosed in this disclosure 10 suggested which a heavy wear and tear of charging plug 45 and charging socket 52 avoid.

In the examples presented, different features and functions of the present disclosure have been described separately from one another and in certain combinations. It goes without saying, however, that many of these features and functions can be freely combined with one another where this is not explicitly excluded.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2016/096194 A1 [0003]

Claims (11)

A charging robot (10) for an electric vehicle (50), comprising a manipulator (12, 13, 14, 15, 16, 17, 18) with an end effector (20), the end effector (20) comprising a charging plug (45) or means (20) for gripping a charging plug (45); a controller (30) which is set up to control movements of the manipulator (12, 13, 14, 15, 16, 17, 18); and Means (25) for measuring instantaneous values of forces and / or moments which act on the charging plug (45) from the outside, wherein the controller (30) is set up to calculate a compensation movement as a function of the measured instantaneous values and to control the manipulator (12, 13, 14, 15, 16, 17, 18) in accordance with the calculated compensation movement. Charging robot (10) for an electric vehicle (50) according to Claim 1 , the controller (30) being set up to control the manipulator (12, 13, 14, 15, 16, 17, 18) in accordance with the calculated compensation movement while the charging plug (45) is completely inserted into a charging socket (52) of an electric vehicle ( 50) is plugged in. The charging robot (10) for an electric vehicle (50) according to any one of the preceding claims, wherein the controller (30) is set up to control the manipulator (12, 13, 14, 15, 16, 17, 18) according to the calculated compensation movement during the charging plug (45) is plugged into a charging socket (52) of an electric vehicle (50) and / or pulled out of it. The charging robot (10) for an electric vehicle (50) according to any one of the preceding claims, wherein the manipulator (12, 13, 14, 15, 16, 17, 18) has a plurality of segments (13, 15, 17) connected via joints (12, 14, 16, 18), and the joints (12, 14, 16, 18) comprise at least one elastic joint and / or the plurality of segments (13, 15, 17) comprises at least one elastic segment. The charging robot (10) for an electric vehicle (50) according to any one of the preceding claims, wherein the means (25) for measuring instantaneous values of forces and / or moments which act from the outside on the charging plug (45) comprise a force / moment sensor, wherein the force / torque sensor is arranged in a joint (12, 14, 16, 18) of the manipulator (12, 13, 14, 15, 16, 17, 18). Charging robot (10) for an electric vehicle (50) according to Claim 5 , further comprising a cover (28) which surrounds the joint (12, 14, 16, 18) in which the force / torque sensor is arranged, the joint (12, 14, 16, 18) seals watertight and consists of a flexible material. The charging robot (10) for an electric vehicle (50) according to any one of the preceding claims, further comprising means (32) for determining whether the electric vehicle (50) is a fleet vehicle. Charging robot (10) for an electric vehicle (50) according to Claim 7 , the controller (30) being set up to control the manipulator (12, 13, 14, 15, 16, 17, 18) depending on the determination of whether the electric vehicle (50) is a fleet vehicle. The charging robot (10) for an electric vehicle (50) according to one of the preceding claims, further comprising means (34) for determining a vehicle type of an electric vehicle (50) to be charged. Charging robot (10) for an electric vehicle (50) according to Claim 9 wherein the controller (30) is set up to use the specific vehicle type to assign a maximum load of the electric vehicle (50) to be charged and / or a height of the charging socket (52) above the floor (90) of the electric vehicle (50) to be charged determine. Charging robot (10) for an electric vehicle (50) according to Claim 10 , the controller (30) being set up to control the manipulator (12, 13, 14, 15, 16, 17, 18) depending on the maximum load and / or the height of the charging socket (52) above the floor (90) to control the electric vehicle to be charged (50).

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