WO2022126568A1

WO2022126568A1 - Wireless charging apparatus, system and method

Info

Publication number: WO2022126568A1
Application number: PCT/CN2020/137470
Authority: WO
Inventors: Sudharsan Dhanachandran
Original assignee: Robert Bosch Gmbh
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2022-06-23
Also published as: CN117015918A

Abstract

A wireless charging apparatus (10) comprises one or more transmitters (11-13), and each transmitter (11-13) comprises a controllable variable output power supply (111); and a charging device configured to: wirelessly send a communication signal to IoT devices (21-26) over a wireless charging range of the transmitter (11-13) and then receive charging requirements from one or more IoT devices (21-26); control the controllable variable output power supply (111) to provide output powers each of which corresponding to one of the charging requirements; and transmit each output power to a corresponding IoT device (21-26) such that a rechargeable battery (211) of each of the IoT devices (21-26) is wirelessly charged with a required power.

Description

WIRELESS CHARGING APPARATUS, SYSTEM AND METHOD

TECHNICAL FIELD

The disclosure generally relates to an apparatus, a system and a method for wirelessly charging batteries of IoT devices.

BACKGROUND

During the last few years, Internet of Things (IoT) devices have started becoming more and more important in production and daily life, because IoT devices can connect wirelessly to a network and have the ability to transmit data. IoT devices have several advantages, such as encouraging an interaction between a machine to machine, providing good automation and control, and possessing strong monitoring feature.

Commonly, an IoT device is using a battery for functioning and transmitting data. The battery disposed in the IoT device is mostly a non-rechargeable battery. In the case of a non-rechargeable battery, if battery life is over, a replacement work is needed. It can be time consuming and costly. There may be a few IoT devices disposed with rechargeable batteries. However, in the case of a rechargeable battery, it needs a dedicated system for charging the battery because output energy of a typical charging system is specific or limited, which is not a cost effective solution.

SUMMARY OF THE INVENTION

This Summary is provided to introduce a group of concepts that are further described below in the Detailed Description. It is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to an embodiment, there provides a wireless charging apparatus comprising one or more transmitters, each transmitter comprising a controllable variable output power supply; and a charging device configured to: wirelessly send a communication signal to IoT devices over a wireless charging range of the transmitter and then receive charging requirements from the IoT devices; control the power supply to provide output powers corresponding to the charging requirements; and transmit each of the output powers to a corresponding IoT device such that rechargeable batteries of the IoT devices are wirelessly charged.

According to an embodiment, there provides a wireless charging system, comprising: a multiple of IoT devices, each IoT device comprising a rechargeable battery and a communication unit for sending a charging requirement; and a wireless charging apparatus as described above, the wireless charging apparatus comprising one or more transmitters, each transmitter being configured to transmit a required power based on the charging requirement to a corresponding IoT device over a wireless charging range of the transmitter.

According to an embodiment, there provides a wireless charging method, optionally performed by means of a wireless charging apparatus as described above, comprising the steps of: wirelessly send a communication signal to IoT devices over a wireless charging range of a transmitter of the wireless charging apparatus and receive charging requirements from the IoT devices; control a power supply of the wireless charging apparatus to provide output powers corresponding to the charging requirements; and transmit each of the output powers to a corresponding IoT device such that rechargeable batteries of the IoT devices are wirelessly charged.

According to an embodiment, there provides a machine readable medium in which instructions are stored, the instructions, when executed by at least one processor, being able to perform the wireless charging method as described above.

It is noted that the above one or more aspects include the following detailed description and features specifically pointed out in the claims. The following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are merely indicative of various ways, principles of various aspects can be practiced and the disclosure is intended to include all such aspects and corresponding transformations.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will here in after be described in connection with the appended drawings that are provided to illustrate and not to limit the disclosed aspects.

Figure 1 schematically illustrates a wireless charging system according to a possible embodiment of the disclosure.

Figures 2a to 2c schematically illustrate some possible constructions of a wireless charging apparatus of the wireless charging system illustrated in Figure 1.

Figure 3 schematically illustrates a working principle of the wireless charging between a transmitter of the wireless charging apparatus and an IoT device.

Figure 4 is an exemplary process of the wireless charging using the wireless charging apparatus according to a possible embodiment of the disclosure;

Figure 5 is another exemplary process for the wireless charging using the wireless charging apparatus according to a possible embodiment of the disclosure; and

Figure 6 is a schematic flow chart of a wireless charging method according to a possible embodiment of the disclosure.

DETAILED DESCRIPTION

The present disclosure will now be discussed with reference to various exemplary embodiments. It should be understood that the discussion of the embodiments is merely intended to enable a person skilled in the art to understand better and thus practice the embodiments of the present invention, but not to teach any limit to the scope of the disclosure.

The disclosure generally relates to a solution for wirelessly charging batteries of IoT devices. According to examples of the disclosure, a charging requirement (e.g., a required power, a desired charging speed and/or priority level) of an IoT device is detected and then the required power is wirelessly transmitted to the IoT device with the desired charging speed and/or priority level. Thus, the energy anxiety of IoT device users is solved without additional labor costs or special charging devices.

A frequent application of the technical solution of the disclosure is in a smart home IoT system. In an example of a smart home IoT system, transmitters are arranged on a ceiling of a room. IoT devices, which are disposed in or associated with home appliances such as an air conditioning, a refrigerator, a washing machine, and a television set, can be wirelessly charged by the transmitters.

The technical solution of the disclosure also can be applied in other scenarios using connected IoT devices. An example of the other scenarios may be a manufacturing environment, an office appliance, an intelligent transportation system (ITS) or a smart supermarket. It is seen that the technical solution of the disclosure may be used in either an indoor environment or an outdoor environment.

Some possible embodiments of the disclosure will be described now.

Figure 1 schematically illustrates a wireless charging system 100 according to a possible embodiment of the disclosure. The wireless charging system 100 mainly comprises a wireless charging apparatus 10 and a multiple of IoT devices 20 (e.g., IoT21～ IoT26) . The wireless charging apparatus 10 is configured to wirelessly charging batteries of the IoT devices based on requirements received from the IoT devices and further based on defined rules. The wireless charging may be implemented by means of beam-based signals such as a RF signal, a laser signal or a WiFi signal.

An application of the wireless charging system 100 illustrated in Figure 1 may be a manufacturing environment. The wireless charging apparatus 10 may be disposed at a given distance above the ground. For example, the wireless charging apparatus 10 is attached to a cantilever of a crane or an arm of a robot. The wireless charging apparatus 10 may be moved or rotated, for example, by means of an operation of the cantilever or the arm.

The wireless charging apparatus 10 may include one or more transmitters. Each transmitter has a wireless charging range, over which a battery of an IoT device can be wirelessly charged. For example, in the case that an IoT device is disposed within a wireless charging range of a transmitter, the IoT device can be wirelessly charged by the transmitter. In the case that the IoT device is moved out of the wireless charging range of the transmitter or the transmitter is moved such that the IoT device is out of the wireless charging range of the transmitter, the IoT device cannot be charged by the transmitter because the IoT device cannot receive energy signals from the transmitter.

Figures 2a to 2c schematically illustrate some possible constructions of the wireless charging apparatus 10.

With reference to Figure 2a, the wireless charging apparatus 10 comprises one transmitter, e.g., a transmitter 11. In the example illustrated in Figure 2a, the transmitter 11 is coupled with a rotating unit (not shown) to rotate the transmitter 11 such that the wireless charging range of the transmitter 11 is changed. In an example, a rotating frequency and/or a rotating angle of the rotating unit may be controlled by the transmitter 11 or an external device associated with the transmitter 11.

With reference to Figure 2b, the wireless charging apparatus 10 comprises one transmitter, e.g., the transmitter 11. In the example illustrated in Figure 2b, the transmitter 11 is coupled with a moving unit (not shown) to drive the transmitter 11 to move such that the wireless charging range of the transmitter 11 is changed. In an example, a moving direction and/or speed of the moving unit may be controlled by the transmitter 11 or an external device associated with the transmitter 11.

In an example, the moving unit may be configured to move based on a predetermined path. The predetermined path may include a multiple of charging stations, and the transmitter is moved from a charging station to a next charging station of the predetermined path. A moving curve of the moving unit may be adjusted by the coupled transmitter.

With reference to Figure 2c, the wireless charging apparatus 10 comprises a multiple of transmitters and the transmitters are arranged such that an area within which all the IoT devices are disposed is covered by the wireless charging ranges of the transmitters. In the example illustrated in Figure 2c, the wireless charging apparatus 10 comprises three transmitters, e.g., transmitters 11～13. The wireless charging ranges of the transmitters 11～13 cover an area within which all the IoT devices (for example, IoT devices 21～26) are disposed.

In an example, the wireless charging ranges of two transmitters may overlap with each other such that there are regions within which an IoT device may be wirelessly charged by two transmitters at the same time. For example, an IoT device disposed in the overlap region A can be wirelessly charged by the transmitters 11 and 12 at the same time. An IoT device disposed in the overlap region B can be wirelessly charged by the transmitters 11 and 13 at the same time. In the case that an IoT device may be wirelessly charged by two transmitters at the same time, a fast charging can be realized. For example, the IoT device 21 is charged by the transmitter 11 with a charging current per unit time, and the IoT device 21 is charged by the transmitters 11 and 12 with 2 times of the charging current per unit time.

It is noted that, in the case that a wireless charging apparatus comprises one transmitter, the transmitter may be coupled with both a rotating unit as described with reference to Figure 2a and a moving unit as described with reference to Figure 2b.

It is noted that, in the case that a wireless charging apparatus comprises a multiple of transmitters, a part the transmitters may be coupled with a rotating unit as described with reference to Figure 2a and another part of the transmitters may be coupled with a moving unit as described with reference to Figure 2b. Each of the rotating units and the moving units can be controlled independently.

For example, the transmitters 11 and 12 are coupled with a rotating unit respectively, and the transmitters 11 and 12 can be rotated synchronously or asynchronously. The transmitter 13 is coupled with a moving unit. The configurations of the transmitters are not limited thereto, and other embodiments of configurations may also be included.

It is noted that three transmitters are illustrated in Figure 2c; however, the apparatus may be implemented with lesser or more number of transmitters.

It is noted that six IoT devices are illustrated in Figure 1; however, the system may include lesser or more number of IoT devices.

It is noted that IoT devices which are in a wireless charging range will change as a rotating and/or moving operation. For example, if IoT devices 21～23 are in the wireless charging range of the transmitter 11, the IoT devices in the wireless charging range may be changed to IoT devices 23～25 after the transmitter 11 is rotated by a given angle.

Figure 3 is a schematic block diagram for illustrating the working principle of the wireless charging operation between a transmitter and an IoT device according to an embodiment of the disclosure.

With reference to Figure 3, in an example, the transmitter 11 comprises a controllable variable output power supply 111 and a charging device couple with the power supply 111. The charging device may comprise several function units each of which may be implemented as hardware, software, or a combination thereof. In an example, the charging device comprises a communication unit 112, a controlling unit 113 and a transmitting unit 114. The IoT device 21 comprises a rechargeable battery 211, a communication unit 212, a controlling unit 213 and a receiving unit 214.

The power supply 111 of the transmitter 11 is configured to be able to be controlled by the controlling unit 113 and provide a variable output power. For example, the controlling unit 113 may provide a first signal to increase an output power of the power supply 111 or provide a second signal to decrease an output power of the power supply 111. The controlling unit 113 may provide a third signal to the power supply 111 such that the power supply 111 outputs a power with a desired power level. In an example, the power supply 111 is a programmable power supply.

The communication unit 112 of the transmitter 11 is able to be connected via a wireless communication link to the communication unit 212 of the IoT device 21. The communication unit 112 of the transmitter 11 is able to send information to the communication unit 212 of the IoT device 21 and receive information from the communication unit 212 via the wireless communication link.

In an example, the communication unit 112 of the transmitter 11 is configured to be connected to a computer server (e.g., a cloud sever) and perform information interaction with the computer server via a wireless communication. For example, the communication unit 112 of the transmitter 11 may receive scheduling information for scheduling the transmitters from the computer server.

The controlling unit 113 is communicatively connected with the power supply 111, the communication unit 112 and the transmitting unit 114 respectively. The controlling unit 113 may include control logic for controlling the power supply 111 to generate a required power corresponding to the charging requirement received from the IoT device 21, and controlling the transmitting unit 114 to obtain the required power from the power supply 111 and to transmit the required power to the IoT device 21. The controlling unit 113 may also include control logic for determining a charging schedule for each of IoT devices, and the charging schedule including at least one of a charging speed and a priority level.

The controlling unit 113 may be implemented as hardware, software, or a combination thereof. In an example, the controlling unit 113 may comprise a processor, using any combination of one or more of a suitable central processing unit, CPU, multiprocessor, microcontroller, digital signal processor, DSP, application specific integrated circuit etc., capable of executing software instructions of a computer program stored in a memory. The memory can thus be considered to be or form part of a computer program product. The processor may be configured to execute a computer program stored therein to cause the controlling unit 113 to perform desired steps.

The controlling unit 213 of the IoT device 21 is communicatively connected with the rechargeable battery 211, the communication unit 212 and the receiving unit 214 respectively. In an example, the controlling unit 213 is configured to check a remaining level of the battery 211, generate a charging requirement signal including the remaining level, charging limitations of the battery 211, control the communication unit 212 to send the charging requirement to the transmitter 11, and control the receiving unit 214, when it receives a required power, to send the required power to the battery 211.

The wireless charging system 100 may further comprise a human machine interface (HMI) 30 wirelessly connected with the wireless charging apparatus 10. The HMI 30 may receive a user input including desired charging parameters and wirelessly send the desired charging parameters to corresponding transmitter (s) . In an example, the HMI comprises an APP operated by users of the IoT devices.

For the sake of clarity, a wireless charging process (e.g. the process 400 described below) between one transmitter (e.g., the transmitter 11) and one IoT device (e.g., the IoT device 21) and a wireless charging process (e.g. the process 500 described below) between one transmitter and several IoT devices will be described. Wireless charging processes between several transmitters and several IoT devices may include a combination of similar processes.

Figure 4 illustrates an exemplary wireless charging process 400 using a wireless charging apparatus according to a possible embodiment of the disclosure.

With reference to Figure 4, at block 402, the communication unit 112 of the transmitter 11 sends a communication signal to the IoT devices over the wireless charging range of the transmitter 11. The communication signal is sent for checking whether there is charging needs of IoT devices. In an example, the communication signal may be implemented as a handshake signal.

In the case that the communication unit 112 does not receive any charging needs from the IoT devices (for example, the communication unit 112 does not receive any charging request signals from the IoT devices) , the process 400 proceeds to block 404.

At block 404, the transmitter 11 is moved and/or rotated such that the wireless charging range of the transmitter 11 is changed, and then the communication unit 112 sends a communication signal to the IoT devices over the changed wireless charging range. This process may be executed one more times until the communication unit 112 receives a charging request signal from an IoT device.

At block 406, the communication unit 112 receives a charging request signal from an IoT device (for example, the IoT device 21) . The charging request signal includes a charging requirement such as specific charging limitation of the battery 211. In an example, the charging requirement includes at least one of a charging voltage requirement, a charging current requirement, a total charging power, a remaining level of a battery of an IoT device, a desired charging speed; and a desired charging priority level.

In an example, at block 408, the communication unit 112 receives a request signal including a user desired charging requirement from the HMI 30. For example, a user of the IoT device 21 desires a fast charging to the battery of the IoT device 21.

At block 410, the controlling unit 113 analyses charging requirements and determines a charging strategy based on analysis results. The charging strategy may include at least one of the following aspects (1) ～ (4) .

(1) The charging limitations of the battery 211 such as a charging voltage and/or a charging current will be determined so as to comply with the requirement from the IoT device 21. The charging limitations may be stored as inherent parameters in the IoT device 21.

(2) A charging speed is determined based on a remaining level of the battery 211. For example, the charging speed is increased with the decreasing in the remaining level of the battery 211. In an example, a table including a relationship between charging speed levels and battery remaining levels is predetermined. The controlling unit 113 may determine the charging speed by means of looking up a speed corresponding to the remaining level of the battery.

(3) In the case that a user request signal is received from the HMI 30, a charging strategy will be determined to meet the user needs. In this way, the wireless charging is quite user friendly.

(4) In the case that a fast charging is determined and thus two or more transmitters are needed to charge the battery at the same time, the controlling unit 113 may control the transmitters to be moved and/or rotated such that the IoT is positioned in an overlap of two charging ranges of two transmitters. The controlling unit 113 may also communicate with transmitters in the vicinity of the transmitter 21 such that some possible transmitters will be moved to charge the battery 211 together. The controlling unit 113 may also communicate with a cloud server and the server will schedule some possible transmitters to charge the battery 211 together.

At block 412, the controlling unit 113 controls the power supply 111 to provide an output power (e.g. a required power) which meets the charging requirement.

At block 414, the controlling unit 113 controls the transmitting unit 114 to transmit the required power to the IoT device 21 based on the determined charging strategy.

Figure 5 illustrates another exemplary wireless charging process 500 using a wireless charging apparatus according to a possible embodiment of the disclosure.

With reference to Figure 5, at block 502, the communication unit 112 of the transmitter 11 sends a communication signal to the IoT devices over the wireless charging range of the transmitter 11. The communication signal is sent for checking whether there is charging needs of IoT devices. In an example, the communication signal may be implemented as a handshake signal.

In the case that the communication unit 112 does not receive any charging needs from the IoT devices (for example, the communication unit 112 does not receive any charging request signals from the IoT devices) , the process 500 proceeds to block 504.

At block 504, the transmitter 11 is moved and/or rotated such that the wireless charging range of the transmitter 11 is changed, and then the communication unit 112 sends a communication signal to the IoT devices over the changed wireless charging range. This process may be executed one more times until the communication unit 112 receives a charging request signal from an IoT device.

At block 506, the communication unit 112 receives charging request signals from two or more IoT devices. Each charging request signal is sent by an IoT device. A charging request signal includes a charging requirement such as specific charging limitation of a battery of an IOT device. In an example, the charging requirement includes at least one of a charging voltage requirement, a charging current requirement, a total charging power, a remaining level of a battery of an IoT device, a desired charging speed; and a desired charging priority level.

In an example, at block 508, the communication unit 112 receives a request signal including a user desired charging requirement from the HMI 30. For example, a user of the IoT devices desires a fast charging to a battery of an IoT device and a slow charging to a battery of another IoT device.

At block 510, the controlling unit 113 analyses charging requirements and determines a charging strategy based on analysis results. The charging strategy may include at least one of the following aspects (1) ～ (6) .

(1) The charging limitations (e.g., a charging voltage and/or a charging current) of a battery of each IoT devices will be determined so as to comply with the requirements from the IoT devices. The charging limitations of a battery may be stored as inherent parameters in an IoT device.

(2) A charging speed for each IoT devices is determined based on a remaining level of a battery of each IoT device. For example, the charging speed is increased with the decreasing in the remaining level. In an example, a table including a relationship between charging speed levels and battery remaining levels is predetermined. The controlling unit 113 may determine the charging speed by means of looking up a speed corresponding to the remaining level of the battery.

(4) A charging priority level for each of the IoT devices is determine based on a remaining level of a battery of each IoT devices. In an example, the priority level is increased with the decreasing in the remaining level. For example, if the remaining level is below 25%, those batteries will have a highest priority. If the remaining level is over 60%, those batteries will have a secondary priority.

(5) A charging priority level for each of the IoT devices is determined based on the distance between the transmitter and each IoT device. In an example, the priority level is increased with the decreasing in the distance.

In an example, the parameter of Packet Reception Rate (PRR) is used to indicate the distance. The Packet Reception Rate is a parameter associated with the proximity of a transmitter and an IoT device. For example, the controlling unit 113 calculates the PRR and determines a charging priority level for each of the IoT devices based on the calculated PRR.

(6) In the case that a fast charging is determined and thus two or more transmitters are needed to charge the battery at the same time, the controlling unit 113 may control the transmitters to be moved and/or rotated such that the IoT is positioned in an overlap of two charging ranges of two transmitters. The controlling unit 113 may also communicate with transmitters in the vicinity of the transmitter 21 such that some possible transmitters will be moved to charge the battery 211 together. The controlling unit 113 may also communicate with a cloud server and the server will schedule some possible transmitters to charge the battery 211 together.

At block 512, the controlling unit 113 controls the power supply 111 to provide output powers (e.g. required powers) each of which meets a charging requirement of a corresponding IoT device.

At block 514, the controlling unit 113 controls the transmitting unit 114 to transmit the required powers to corresponding IoT devices based on the determined charging strategy.

The disclosure provides a wireless charging method, which can be performed by using the above described wireless charging apparatus. For this reason, various features described above with reference to the wireless charging apparatus are also applicable in the wireless charging method, and thus the description to them is omitted.

A wireless charging method according to a possible embodiment of the disclosure is schematically shown in Figure 6 and mainly comprises the steps described below.

In step 602, a communication signal is wirelessly sent to IoT devices over a wireless charging range of a transmitter and charging requirements are received from one or more IoT devices.

In step 604, a power supply of the transmitter is controlled to provide output powers corresponding to the charging requirements.

In step 606, each of the output powers is transmitted to a corresponding IoT device such that rechargeable batteries of the IoT devices are wirelessly charged.

The disclosure also provides a machine readable medium in which instructions are stored, the instructions, when executed by at least one processor, being able to perform the wireless charging method described above.

It is noted that software should be considered broadly to represent instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, running threads, processes, functions, and the like. Software can reside on computer readable medium. Computer readable medium may include, for example, a memory, which may be, for example, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip) , an optical disk, a smart card, a flash memory device, a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, or a removable disk. Although a memory is shown as being separate from the processor in various aspects presented in this disclosure, a memory may also be internal to the processor (e.g., a cache or a register) .

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalent transformations to the elements of the various aspects of the present disclosure, which are known or to be apparent to those skilled in the art, are intended to be covered by the claims.

Claims

A wireless charging apparatus comprising one or more transmitters, each transmitter comprising:

a controllable variable output power supply; and

a charging device configured to:

wirelessly send a communication signal to IoT devices over a wireless charging range of the transmitter, and receive charging requirements from one or more IoT devices;

control the power supply to provide output powers each of which corresponding to one of the charging requirements; and

transmit each output power to a corresponding IoT device such that a rechargeable battery of each of the IoT devices is wirelessly charged with a required power.
The wireless charging apparatus of claim 1, wherein a charging requirement sent by an IoT device includes at least one of the following parameters associated with a battery of the IoT device:

- a charging voltage requirement;

- a charging current requirement;

- a total charging power;

- a remaining level of a battery;

- a desired charging speed; and

- a desired priority level.
The wireless charging apparatus of claim 1 or 2, wherein the charging device is configured to determine a charging schedule for each of the IoT devices according to the charging requirements;

optionally, the charging schedule includes at least one of a charging speed and a priority level.
The wireless charging apparatus of any one of claims 1 to 3, wherein the charging device is configured to determine a charging speed for each of the IoT devices according to a remaining level of a battery of each IoT device,

optionally, the charging speed is increased with the decreasing in the remaining level.
The wireless charging apparatus of any one of claims 1 to 4, wherein the charging device is configured to determine a priority level for each of the IoT devices based on a remaining level of a battery of each IoT device,

optionally, the priority level is increased with the decreasing in the remaining level.
The wireless charging apparatus of any one of claims 1 to 5, wherein the charging device is configured to receive a request signal including at least one of a user desired charging speed and a user desired priority level from a HMI; and

the charging device is configured to determine a charging schedule for the IoT devices based on the request signal.
The wireless charging apparatus of any one of claims 1 to 6, wherein the charging device is configured to determine a priority level for each of the IoT devices based on a distance between the transmitter and each of the IoT devices,

optionally, the priority level is increased with the decreasing in the distance.
The wireless charging apparatus of any one of claims 1 to 7, wherein the transmitter is coupled with a rotating unit to rotate the transmitter such that the wireless charging range of the transmitter is changed.
The wireless charging apparatus of claim 8, wherein the charging device is communicatively connected with the rotating unit and configured to adjust a rotating frequency and/or a rotating angle of the rotating unit.
The wireless charging apparatus of claim 8 or 9, wherein the charging device is configured to, in the case that the charging device does not receive any charging requirements, control the rotating unit to rotate, optionally, by a predetermined angle, such that the charging range of the transmitter is changed.
The wireless charging apparatus of any one of claims 1 to 10, wherein the transmitter is coupled with a moving unit to move the transmitter such that the wireless charging range of the transmitter is changed,

optionally, the moving unit is configured to move based on a predetermined path or a moving path of the moving unit is adjusted by the charging device.
The wireless charging apparatus of claim 11, wherein the charging device is communicatively connected with the moving unit and configured to, in the case that the charging device does not receive any charging requirements, control the moving unit to move to a next charging station of the predetermined path.
The wireless charging apparatus of any one of claims 1 to 12, wherein the wireless charging apparatus comprises two or more transmitters, the two or more transmitters being arranged such that an area within which all the IoT devices are disposed is covered by the wireless charging ranges of the two or more transmitters.
The wireless charging apparatus of claim 13, wherein a part of the transmitters are coupled with rotating units and another part of the transmitters are coupled with moving units; and

each of the rotating units and the moving units is independently controlled.
The wireless charging apparatus of claim 13 or 14, the charging device is configured to control two or more transmitters to charge an IoT device at the same time in the case that a fast charging process is required.
A wireless charging system comprising:

a multiple of IoT devices, each IoT device comprising a rechargeable battery and a communication unit for sending a charging requirement; and

a wireless charging apparatus as described in any one of claims 1 to 15, the wireless charging apparatus comprising one or more transmitters, each transmitter being configured to transmit a required power based on the charging requirement to a corresponding IoT device over a wireless charging range of the transmitter.
The wireless charging system of claim 17, wherein the wireless charging system further comprises an HMI for receiving a user input including at least one of a user desired charging speed and a user desired priority level,

optionally, the HMI comprises an APP operable by users of the IoT devices.
A wireless charging method, optionally performed by means of a wireless charging apparatus of any one of claims 1 to 15, comprising the steps of:

wirelessly send a communication signal to IoT devices over a wireless charging range of a transmitter of the wireless charging apparatus and receive charging requirements from one or more IoT devices;

control a power supply of the wireless charging apparatus to provide output powers each of which corresponds to one of the charging requirements; and

transmit the output powers to the IoT devices such that a rechargeable battery of each of the IoT devices is wirelessly charged with a required power.
A machine readable medium in which instructions are stored, the instructions, when executed by at least one processor, being able to perform the method of claim 18.