Method and device for carrying out an inductive charging process of a battery in a vehicle

Abstract

The present invention relates to a method and devices for carrying out an inductive charging process of a battery in a vehicle. The method according to the invention comprises the following steps. First, a vehicle correctly positioned over a base plate for the inductive charging process is detected. Furthermore, an environmental detection system is used, designed to detect living objects within a defined area. If no living objects are detected within the defined area, the z-distance between the vehicle and the base plate is reduced until a predefined distance is reached. The charging process is then started.

Description

[0001] The present invention relates to a method and devices for carrying out an inductive charging process of a battery in a vehicle.

[0002] Charging vehicle batteries plays a central role in the attractiveness of electromobility. Therefore, more and more proposals are being made to simplify and improve the convenience of this process. Inductive charging of electric vehicles is one such innovative technology that enables wireless charging. This system is based on the principle of electromagnetic induction and uses two copper coils. An electric current is applied to a primary coil in a base plate embedded in the ground, generating a magnetic field that induces current in a secondary coil inside the vehicle. The induced alternating current is then converted into direct current to charge the vehicle battery. Advantages of this technology include more convenient charging without the need to handle cables, the ability to charge during short stops, such as at bus stops, easy integration into parking spaces, and the potential for dynamic charging while driving.Positioning the vehicle above the ground pad, also known as the "ground pad module," presents a challenge, as both the correct location and the correct distance between the vehicle unit with the secondary coil and the ground pad with the primary coil are crucial. Safety also poses a challenge, as it must be ensured that no persons or other living beings, referred to simply as "living objects" in the application, are within the area of ​​the coils.

[0003] Various systems and methods are known from the prior art. Documents DE 10 2017 211 373 A1, DE 10 2014 222 486 A1, DE 10 2012 105 615 A1 and US 2023 0 246 488 A1 disclose different methods for inductive charging in which the environment is monitored to exclude living objects from the danger zone and to guarantee the safe positioning of the vehicle unit with secondary coil above the primary coil.

[0004] Documents DE 10 2015 217 274 A1 and DE 10 2015 011 211 A1 further disclose a sensor system that measures the vertical distance between the secondary coil and the primary coil, and thus between the vehicle unit and the base plate. This distance is referred to as the z-distance in the application.

[0005] Document US 2021 / 0 268 922 A1 discloses a contactless charging system for vehicles with a floor-mounted lifting device for raising the charging coil and foreign object detection between the coils. It also discloses a system for aligning charging coils for wireless charging. Document US 2012 / 0 262 002 A1 describes systems and methods for antenna alignment and vehicle guidance for wireless charging of electric vehicles. It uses field strength sensors for position determination and includes safety sensors for detecting animals or children in the vicinity of the vehicle antennas. Document DE 10 2018 105 624 A1 discloses an inductive charging system with vehicle-mounted active suspension for height adjustment. The height is optimized based on charging information (crowd-sourced data) to maximize charging efficiency. Document DE 10 2014 222 486 A1 discloses a method for safety monitoring during inductive charging.Living objects are detected in a safety area around the charging zone and, if necessary, the transmission is switched off or the charging process is blocked.

[0006] Against the background of the prior art described above, the object of the present invention is to provide a method and devices for carrying out an inductive charging process of a battery in a vehicle, by means of which safety can be improved and optimal placement of the vehicle above the floor plate can be ensured.

[0007] This problem is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are disclosed in the dependent claims. It should be noted here that advantageous embodiments of the method according to the invention are also to be understood as disclosures of advantageous embodiments of the devices according to the invention, and vice versa.

[0008] The inventive method for carrying out an inductive charging process of a battery in a vehicle comprises the following steps. First, a vehicle correctly positioned over a base plate for the inductive charging process is detected. This is done by means of suitable sensors in the vehicle or in the base plate. The acquired sensor data is preferably transmitted both to the vehicle and to a control unit of a charging system to which the base plate belongs. Preferably, instructions for the correct positioning of the vehicle over the base plate are provided to the driver.

[0009] Furthermore, environmental detection is performed using sensors, preferably integrated into the base, designed to detect living objects within a defined area, and thus also within a defined area of ​​the vehicle. If no living objects are detected within the defined area, the z-distance between the vehicle and the base plate is reduced until a predefined distance is reached. For this purpose, the z-distance is continuously determined and monitored using suitable sensors, such as ultrasonic sensors, radar sensors, light barriers, or similar devices. Subsequently, the inductive charging process is initiated and carried out, particularly while continuously monitoring for living objects within the environment.The charging process involves energizing the primary coil in the base plate, thereby inducing a current in the secondary coil in the vehicle, which then charges the battery. Upon detection of a living object within the defined area, the charging process is preferably terminated immediately. The predefined distance between the vehicle and the base plate, i.e., between the vehicle's secondary coil and the base plate's primary coil, is specifically determined by an optimal distance for inductive charging, ensuring the most efficient possible current induction in the secondary coil.

[0010] The method according to the invention ensures, firstly, that the charging process poses no danger to persons or animals that may approach the vehicle. Secondly, it ensures an efficient and therefore time-saving charging process.

[0011] In an advantageous embodiment of the method according to the invention, the defined area of ​​the vehicle, within which living objects are detected by the environmental sensing system, comprises the vehicle interior and / or a defined distance from the vehicle. This defined distance can be, for example, a value of 1.5 m or similar around the vehicle. If a person is detected within this area, the charging process is not started.

[0012] In a further advantageous embodiment of the method according to the invention, the reduction of the z-distance is achieved by lowering the vehicle. For this purpose, sensor data regarding the z-distance and / or environmental perception data are preferably transmitted to the vehicle. This is preferably done via WLAN or other wireless communication interfaces. The environmental perception sensors can also be used to determine the z-distance. The lowering of the vehicle is then preferably achieved by a level control system of the vehicle's suspension. Level control is understood to be a system in motor vehicles that maintains, raises, or lowers the vehicle height, i.e., the ground clearance above the ground. Its main purpose is to ensure optimal ground clearance and a level position of the vehicle under changing load and stress conditions.Since modern vehicles sometimes have self-leveling suspension, the vehicle can be lowered for charging using the existing hardware. This can result in significant cost savings.

[0013] According to the invention, the areas in the floor where the vehicle's wheels are positioned correctly for inductive charging are lowered independently of the base plate. For this purpose, appropriate actuators are provided in the floor of the charging system, which, for example, can hydraulically lower or raise the vehicle relative to the base plate. While this requires the installation of additional hardware in the floor of the charging system, it allows the method to be applied to all vehicles, regardless of whether they have level control or not. In this embodiment, the entire vehicle is thus lowered by means of the areas in the floor that are lowered and brought closer to the base plate.

[0014] In a further embodiment of the method according to the invention, the base plate can alternatively or additionally be raised relative to the vehicle. Thus, the vehicle remains unchanged, and only the base plate is moved vertically towards the underbody of the vehicle to reduce the z-distance and enable the most efficient charging process possible. Therefore, the method can also be carried out independently of the vehicle's equipment; however, an actuator for the base plate must be provided to adjust its height.

[0015] For all designs with actuators in the floor to adjust the z-distance, hydraulic actuators are a suitable option. However, other types of actuators can also be used.

[0016] A device not according to the invention for carrying out an inductive charging process of a battery in a vehicle, also referred to as a charging system within the scope of the application, comprises a base plate, in particular one embedded in the ground, which includes a primary coil for the inductive charging process. Furthermore, it comprises sensors for performing environmental detection in the area of ​​the base plate and for determining a z-distance, configured to detect living objects within a defined area. A device according to the invention also comprises a communication device configured to transmit data acquired by the sensors to a vehicle with an interface appropriately configured to receive such data. This is accomplished via common communication media such as WLAN or other wireless communication interfaces.The sensors whose data are transmitted include sensors for environmental detection and / or for determining the z-distance. The inventive method can be carried out using the device designed in this way.

[0017] The device according to the invention thus makes it possible to transmit necessary information to the vehicle, which enables the vehicle to be lowered safely, for example by means of the level control of the chassis.

[0018] Another device according to the invention, which enables the implementation of the method according to the invention, also has a base plate which includes a primary coil for the inductive charging process, and sensors for performing environmental detection in the area of ​​the base plate and for determining a z-distance, designed to detect living objects in a defined area. Furthermore, it has an actuator provided in the base, designed to reduce the z-distance between the vehicle and the base plate and to lower areas in the base where the vehicle's wheels are in the correct position for the inductive charging process, independently of the base plate. The actuator is controlled by a control unit depending on the z-distance.

[0019] In an advantageous embodiment of the invention, the sensor, particularly for environmental detection, is designed as a capacitive sensor. It is further arranged in a circumferential area of ​​the base plate, particularly in the corners of the base plate, and preferably has a detection range of 260 degrees. Sensors for environmental detection, especially for the detection of living objects, are already known from the prior art and therefore do not need to be explained further here.

[0020] With reference to the accompanying figure, the invention is explained in more detail below. The figure shows an exemplary flowchart of an embodiment of the method according to the invention.

[0021] Step S0 marks the start of the process. A driver approaches an inductive charging station and parks the vehicle over the charging pad. In step S1, the system first detects whether the vehicle is parked and positioned over the pad in such a way that inductive charging is possible. If not, step S11 provides the driver with instructions on how to reposition the vehicle. Position detection can be performed by the vehicle itself, using sensors such as a camera to determine if it is correctly positioned. Alternatively, this information can be acquired by sensors embedded in the charging system's base and transmitted to the vehicle via an interface. Fixed displays on the ground or in front of the vehicle are also conceivable, providing the driver with the relevant information.

[0022] Once the correct vehicle position is detected, process step S2 checks whether the inductive charging functionality is activated in the vehicle. If not, the process is terminated in step S21 until the functionality is activated. A corresponding notification can also be displayed to the driver at this stage. Similarly, embodiments are conceivable in which the function is activated automatically, for example, after the correct charging position is detected, or in which activation of the function is unnecessary or permanent activation is preset.

[0023] In a further process step S3, an environmental assessment is then carried out to determine whether a person or other living being is located in a defined area in or around the vehicle. If this is the case, no further action is authorized, as indicated by step S31. The environmental assessment continues continuously throughout this process.

[0024] If no living object is detected within the defined area, the process is released and continues with step S4, in which the release is communicated to the vehicle. This communication preferably takes place via WLAN or other wireless interface technologies for data exchange.

[0025] Subsequently, in step S5, a z-distance from the vehicle floor at the location of the secondary coil to the base plate is determined in the vertical direction. This is done either via appropriate sensors in the base plate or in the vehicle.

[0026] In step S6, this distance is checked and compared against a defined limit. If the limit is already undershot, the charging process can be started directly in step S61. If not, the vehicle is lowered to a target value for the z-distance. This is preferably done via the vehicle's level control in step S7.

[0027] In alternative embodiments, the z-distance between the vehicle and the base plate can also be reduced in other ways, such as by suitable actuators in the floor that raise the base plate or lower the vehicle relative to the base plate.

[0028] Once the defined target value of the z-distance is reached, the primary coil is energized in step S8, thus starting the charging process.

[0029] The optimal z-distance is determined in advance. Factors such as the desired charging speed, external conditions like weather, and a desired standby time can be taken into account.

[0030] The charging process itself, as well as the lowering of the vehicle, preferably takes place under continuous environmental monitoring by sensors. If, for example, a person enters the defined area detected by the environmental monitoring system, the charging process is automatically stopped.

[0031] The sensor system for environmental detection is preferably designed using capacitive sensors located at the edges, particularly at the corners of the base plate. These sensors have a wide detection angle and can reliably detect living objects within their detection range.

[0032] By initiating the charging process and lowering the vehicle based on environmental detection, it can be ensured that the inductive charging process can be carried out safely, even without a person having to remain permanently in or near the vehicle.

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