Table AGV wireless charging system

Abstract

The application relates to a desktop AGV wireless charging system, which comprises a transmitting end module, a receiving end module and the like, wherein the transmitting end module comprises a transmitting end coil group laid in an AGV work desktop, the transmitting end coil group comprises one or a plurality of transmitting end non-resonant coils connected in parallel, at least one receiving end module is correspondingly arranged on at least one AGV trolley, the receiving end module comprises a receiving end resonant coil located at the bottom of the AGV trolley, the receiving end resonant coil and the transmitting end non-resonant coil are coupled through a near-field magnetic field to perform energy transmission, based on the coupled mode theory, all the transmitting end non-resonant coils and all the receiving end resonant coils satisfy that the reflection coefficient of the system with each receiving end resonant coil as a unit is zero in the state that energy transmission is performed between any one receiving end resonant coil and any one or more transmitting end non-resonant coils. The application meets the demand that the AGV trolley works while being charged, saves time cost, guarantees high transmission efficiency of the charging system and avoids the splitting problem of the working frequency.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a desktop AGV wireless charging system. Background Technology

[0002] With advancements in technology across industries and electronics, the demand for work efficiency is constantly increasing. AGV (Automated Guided Vehicle) industrial robots, also commonly known as AGV carts, are transport vehicles equipped with electromagnetic or optical automatic navigation devices. They rely on information from computers or electromagnetic tracks to move and perform various transport functions. For factories or workbenches requiring rapid sorting of goods or parts, a compact and easy-to-operate small AGV plays a crucial role in the sorting process.

[0003] Small AGVs typically use rechargeable batteries as their power source, and charging methods generally fall into two categories: contact charging and wireless charging. Due to the diverse goods transported and working environments of small AGVs, traditional contact charging solutions are insufficient to meet their charging requirements. Furthermore, if wireless charging is implemented using charging stations, the AGV must be parked near the charging station and wait for charging to complete, wasting valuable time. Additionally, if a dual-resonance system is used for wireless charging of small AGVs, the strong near-field coupling can cause severe frequency splitting in the operating frequency. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a desktop AGV wireless charging system, which solves the problems of inconvenience and low efficiency of traditional wireless charging methods, as well as the severe frequency splitting caused by dual-resonance charging systems.

[0005] This invention is achieved through the following solution: a desktop AGV wireless charging system, comprising:

[0006] A transmitter module, the transmitter module including a transmitter coil group laid in the AGV work table, the transmitter coil group including one or more transmitter non-resonant coils connected in parallel;

[0007] At least one receiving module is installed on at least one AGV vehicle in a one-to-one correspondence. The receiving module includes a receiving resonant coil located at the bottom of the AGV vehicle. The receiving resonant coil and the transmitting non-resonant coil are coupled through a near-field magnetic field for energy transfer.

[0008] Based on coupled-mode theory, all the non-resonant coils at the transmitting end and all the resonant coils at the receiving end satisfy the condition that, under the state of energy transfer between any one of the resonant coils at the receiving end and any one or more of the non-resonant coils at the transmitting end, the reflection coefficient of the system on a unit basis for each resonant coil at the receiving end is zero.

[0009] A further improvement of the desktop AGV wireless charging system of the present invention is that the specifications of the transmitting end non-resonant coil and the receiving end resonant coil satisfy that, under the condition that any one of the receiving end resonant coils transmits energy with any one or more of the transmitting end non-resonant coils, the operating frequency of the charging system, with each receiving end resonant coil as a unit, is equal to the local oscillator frequency of the system, and the energy feed-in gain rate of the system is equal to the sum of the energy output loss rate and the intrinsic loss rate of the system.

[0010] A further improvement of the desktop AGV wireless charging system of the present invention is that all the non-resonant coils at the transmitting end have the same specifications, and all the resonant coils at the receiving end have the same specifications.

[0011] A further improvement of the desktop AGV wireless charging system of the present invention is that the non-resonant coil of the transmitting end is a long strip coil, and the size of the non-resonant coil of the transmitting end is larger than the size of the resonant coil of the receiving end.

[0012] A further improvement of the desktop AGV wireless charging system of the present invention is that the receiving end resonant coil is a square coil.

[0013] A further improvement of the desktop AGV wireless charging system of the present invention is that bakelite for winding the non-resonant coil of the transmitter is laid on the desktop of the AGV, and grooves are provided on the bakelite according to the winding method of the non-resonant coil of the transmitter.

[0014] A further improvement of the desktop AGV wireless charging system of the present invention is that the transmitter module further includes a transmitter circuit, wherein the input terminal of the transmitter circuit is connected to the power supply and the output terminal is connected to the transmitter coil group.

[0015] A further improvement of the desktop AGV wireless charging system of the present invention is that the transmitting end circuit includes a first rectifier circuit, a first voltage adjustment circuit and an inverter circuit connected in sequence, the first rectifier circuit is connected to the power supply and the inverter circuit is connected to the transmitting end coil group.

[0016] A further improvement of the desktop AGV wireless charging system of the present invention is that the receiving module further includes a receiving circuit, wherein the input end of the receiving circuit is connected to the receiving resonant coil and the output end is connected to the AGV load.

[0017] A further improvement of the desktop AGV wireless charging system of the present invention is that the receiving end circuit includes a second rectifier circuit and a second voltage adjustment circuit connected in sequence, the second rectifier circuit being connected to the receiving end resonant coil, and the second voltage adjustment circuit being connected to the AGV load.

[0018] This invention utilizes a wireless charging method that lays out a transmitter coil array within the AGV's work surface. This effectively avoids the risks associated with traditional contact charging in complex environments, meeting the AGV's need to charge while working, significantly saving time and improving its efficiency. By ensuring that the non-resonant transmitter coil and the resonant receiver coil meet certain conditions, high transmission efficiency is guaranteed during AGV charging. Furthermore, by employing a single-resonance wireless charging system, the system operates at a single frequency, preventing frequency splitting issues. Attached Figure Description

[0019] Figure 1 A system block diagram of the desktop AGV wireless charging system of the present invention is shown.

[0020] Figure 2 A circuit block diagram of the desktop AGV wireless charging system of the present invention is shown.

[0021] Figure 3 A comparative schematic diagram of a non-resonant transmitting coil and a resonant receiving coil in this invention is shown.

[0022] Figure 4 A schematic diagram is shown of the non-resonant coil of the transmitting end in this invention wound on a grooved bakelite.

[0023] Figure 5 A simplified schematic diagram is shown of an AGV trolley using the wireless charging system of the present invention to charge while working. Detailed Implementation

[0024] Due to the diverse goods transported and working environments of small AGVs, traditional contact charging solutions are insufficient to meet their charging requirements. Furthermore, if wireless charging is achieved using charging stations, the AGV must be parked near the charging station and wait for charging to complete, wasting time. Additionally, if a dual-resonance system is used for wireless charging of small AGVs, the strong near-field coupling causes severe frequency splitting. Against this backdrop, this invention provides a desktop AGV wireless charging system that solves the problems of inconvenience and low efficiency of traditional wireless charging methods, as well as the severe frequency splitting caused by dual-resonance charging systems. The desktop AGV wireless charging system will be further described below with reference to specific embodiments and accompanying drawings.

[0025] See Figures 1-5 As shown, a desktop AGV wireless charging system includes:

[0026] The transmitter module includes a transmitter coil assembly laid out on the AGV worktable 1. The transmitter coil assembly includes one or more transmitter non-resonant coils (L1, ..., L2) connected in parallel. f At least one receiving module is installed on at least one AGV trolley 2 in a one-to-one correspondence. The receiving module includes a receiving resonant coil L located at the bottom of the AGV trolley 2. j The receiving end resonant coil L j Energy is transferred through near-field magnetic field coupling with each of the non-resonant coils at the transmitting end; based on the coupled-mode theory, all the non-resonant coils (L1, ..., Lf) at the transmitting end and all the resonant coils Lj at the receiving end on the AGV trolley 2 satisfy that the reflection coefficient of the system, on a unit basis, is zero when any one of the resonant coils Lj at the receiving end is transferring energy with any one or more of the non-resonant coils at the transmitting end.

[0027] In this embodiment, as Figure 2 As shown, the transmitter module also includes a transmitter circuit, which includes a first rectifier circuit, a first voltage adjustment circuit, and an inverter circuit connected in sequence. The first rectifier circuit is connected to the power supply, and the inverter circuit is connected to the transmitter coil group. The receiver module also includes a receiver circuit, which includes a second rectifier circuit and a second voltage adjustment circuit connected in sequence. The second rectifier circuit is connected to the receiver resonant coil Lj, and the second voltage adjustment circuit is connected to the AGV load. The power supply for the transmitter is AC220V, 50Hz AC mains power. After the first rectifier circuit converts the AC power to DC power, the first voltage adjustment circuit reduces the DC voltage to DC5V, and then the inverter circuit converts it back to AC power before inputting it to all the transmitter non-resonant coils in the transmitter coil group. When the AGV is running on the AGV worktable 1, the receiver resonant Lj on the AGV is connected to the near-field transmitter non-resonant coils through magnetic field coupling. j The received high-frequency electromagnetic wave is input to the second rectifier circuit for AC-DC rectification, which converts it into DC power. Then, it is regulated by the second voltage adjustment circuit for DC-DC voltage regulation before being supplied to the AGV load. The system can operate at a power of 300W and output 50V, 6A or 24V, 12A DC power.

[0028] Furthermore, the principle of designing a non-resonant coil at the transmitting end and a resonant coil at the receiving end based on coupled-mode theory to make the reflection coefficient of the charging system zero under any charging state is as follows:

[0029] First, coupled-mode theory is a theory used to study the general laws governing the coupling between two or more electromagnetic wave modes. For the wireless charging system of this invention, the expression of coupled-mode theory is as follows:

[0030]

[0031] in: It is a characterization of the waveform vibration of the receiving end resonant coil; ω0 is the intrinsic frequency of the receiving end resonant coil; i is the imaginary part; γf is the energy feed gain rate; δj is the energy output loss rate; Γf is the intrinsic loss rate caused by the inherent loss of the transmitting end non-resonant coil; S 1+ Aj is the incident coefficient; Aj is the amplitude of the resonant coil at the receiving end.

[0032] The resonant coil L at the receiving end j When energy is transferred to any one or more of the non-resonant coils at the transmitting end, the expression for the amplitude Aj of the resonant coil at the receiving end is:

[0033]

[0034] The expression for the reflection coefficient S1- is:

[0035]

[0036] The expression for the system's transmission efficiency η is:

[0037]

[0038] Where: S2- is the transmission coefficient at the system output.

[0039] Due to the system's reflection coefficient S 1- The smaller the value, the greater the system's transmission efficiency η. Therefore, by setting expression (3) to zero, we can obtain the system with the maximum transmission efficiency η. max The conditions are: ω = ω0 and γ f =δ j +Γ f Where: ω is the operating frequency of the system.

[0040] Substituting the above conditional equations into the transmission efficiency expression (4) yields the maximum transmission efficiency η. max for:

[0041]

[0042] In summary, when a receiving resonant coil is magnetically coupled to a transmitting non-resonant coil, the system's operating frequency ω is equal to the system's local oscillator frequency ω0, and the system's energy feed gain rate γ... f Equal to the system's energy output loss rate δj and intrinsic loss rate Γ f When the sum of these two values ​​is equal, it can satisfy the requirement of high transmission efficiency.

[0043] To ensure high transmission efficiency of the wireless charging system of this invention under various coil combinations, the design of the number, size, number of turns, specifications, and layout of the non-resonant coil at the transmitting end and the resonant coil at the receiving end should consider meeting the above conditions. It should be noted that once the circuit of the wireless charging system is determined, the energy feed gain rate γ in the system... f Energy output loss rate δ j and intrinsic loss rate Γ f The values ​​of the equal coefficients can all be calculated using the corresponding formulas. The specific calculation methods are common knowledge in the field and will not be elaborated here. In order to simplify the design of each coil, as a preferred embodiment, all the non-resonant coils of the transmitting end have the same size, number of turns, and specifications, and all the resonant coils of the receiving end have the same size, number of turns, and specifications.

[0044] Better, such as Figure 3 The non-resonant coil L at the transmitting end f It is one of several non-resonant coils at the transmitting end, measuring 500mm × 200mm, and is formed into a long strip-shaped single-layer coil, in conjunction with... Figure 4 and Figure 5 As shown, the AGV worktable 1 has a non-resonant coil L installed below the preset track for the transmitter. f The baked wick 3 is wound with the non-resonant coil L at the transmitting end. f The winding method features grooves, and all the non-resonant coils Lf at the transmitting end are connected in parallel and wound onto the bakelite 3 using a loose winding method with Litz wire, embedding them into the corresponding grooves. The illustrated number of turns is 5 turns, but the actual number of turns can be 5 to 8 turns. The resonant coil Lj at the receiving end is smaller than the non-resonant coils Lf at the transmitting end, with dimensions of 100mm × 100mm. It is formed into a square double-layer coil and wound using a tight winding method with Litz wire. The illustrated number of turns is 8 turns, but the actual number of turns can be 8 to 10 turns. Several desktop AGVs serving as receivers can wirelessly charge on any of the non-resonant coils Lf at the transmitting end during operation, performing tasks such as sorting along a preset track. This allows the AGVs to charge while working. For desktops 1 with waiting areas, non-resonant coils at the transmitting end can also be placed in the waiting area, allowing the AGVs to charge while waiting. If the size of the non-resonant coil Lf at the transmitting end is larger than the size of the resonant coil Lj at the receiving end, it can simultaneously accommodate charging of two or more AGVs that are in operation. Figure 5As shown, in this embodiment, one transmitting non-resonant coil Lf can wirelessly charge two AGVs simultaneously. Of course, since the AGVs are in operation, they may run between the two transmitting non-resonant coils. Therefore, there are also cases where two adjacent transmitting non-resonant coils wirelessly charge the same AGV.

[0045] The design principle of this invention will be verified in three different scenarios:

[0046] 1. The case of a non-resonant coil at the transmitting end and a resonant coil at the receiving end, in which case γf=γ1, δj=δ1, Γ f =Γ1.

[0047] The equation of motion based on coupled-mode theory is:

[0048]

[0049] The expression for the amplitude A1 of the resonant coil at the receiving end is:

[0050]

[0051] Reflection coefficient S 1- The expression is:

[0052]

[0053] The expression for the system's transmission efficiency η is:

[0054]

[0055] When ω=ω0 and γ1=δ1+Γ1, the reflection coefficient S can be obtained. 1- =0, therefore, substituting these two equations into the transmission efficiency expression (4') yields the maximum transmission efficiency:

[0056]

[0057] 2. Considering a single non-resonant coil at the transmitting end and n (n is a natural number greater than 1) resonant coils at the receiving end, taking n=2 as an example, the first resonant coil has γf=γ1, δj=δ1, and Γ... f =Γ1; the second receiving end resonant coil has γf = γ2, δj = δ2, Γ f =Γ2.

[0058] The equation of motion based on coupled-mode theory is:

[0059]

[0060] Assume that all receiver resonant coils have identical dimensions, number of turns, and specifications, i.e., γ1=γ2=γn, Γ1=Γ2=Γ n Then the expression for the amplitude An of each receiving resonant coil is:

[0061]

[0062] The expression for the reflection coefficient under each receiver resonant coil is:

[0063]

[0064] The expression for the system's transmission efficiency η is:

[0065]

[0066] When ω=ω0 and γn=δn+Γ n When the reflection coefficient S is obtained, it can be obtained. 1- =0, therefore, substituting these two equations into the transmission efficiency expression (4”) yields the maximum transmission efficiency:

[0067]

[0068] 3. The case of two non-resonant coils at the transmitting end and one resonant coil at the receiving end, in which case γf=γ'1+γ'2=γ1 or γ2, δj=δ1, Γ f =Γ1, where γ'1 is the energy radiation rate of the previous non-resonant coil at the transmitting end and shows a decreasing trend, and γ'2 is the energy radiation rate of the next non-resonant coil at the transmitting end and shows an increasing trend.

[0069] The equation of motion based on coupled-mode theory is:

[0070]

[0071] The expression for the amplitude A1 of the resonant coil at the receiving end is:

[0072]

[0073] The expression for the system's reflection coefficient is:

[0074]

[0075]

[0076] The expression for the system's transmission efficiency η is:

[0077]

[0078] When ω=ω0 and γ'1+γ'2=δ1+Γ1, the reflection coefficient S can be obtained. 1- =0, therefore, substituting these two equations into the transmission efficiency expression (4”') yields the maximum transmission efficiency:

[0079]

[0080] The above verification shows that the present invention designs each coil based on coupled-mode theory, so that the specifications of all transmitting non-resonant coils and receiving resonant coils meet the following requirements: when any one of the receiving resonant coils transmits energy to any one or more of the transmitting non-resonant coils, the operating frequency ω of the charging system, with each receiving resonant coil as a unit, is equal to the local oscillator frequency ω0 of the system, and the energy feed gain rate γf of the system is equal to the sum of the energy output loss rate δj and the intrinsic loss rate Γf of the system.

[0081] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A desktop AGV wireless charging system, characterized in that, include: A transmitter module, the transmitter module including a transmitter coil group laid in the AGV work table, the transmitter coil group including one or more transmitter non-resonant coils connected in parallel; At least one receiving module is installed on at least one AGV vehicle in a one-to-one correspondence. The receiving module includes a receiving resonant coil located at the bottom of the AGV vehicle. The receiving resonant coil and the transmitting non-resonant coil are coupled through a near-field magnetic field for energy transfer. Based on coupled-mode theory, all the non-resonant coils at the transmitting end and all the resonant coils at the receiving end satisfy the condition that, under the state of energy transfer between any one of the resonant coils at the receiving end and any one or more of the non-resonant coils at the transmitting end, the reflection coefficient of the charging system, with each resonant coil at the receiving end, is zero. The specifications of the transmitting non-resonant coil and the receiving resonant coil satisfy the following condition: when any one of the receiving resonant coils transmits energy to any one or more of the transmitting non-resonant coils, the operating frequency of the charging system, with each receiving resonant coil as a unit, is equal to the local oscillator frequency of the system, and the energy feed gain rate of the system is equal to the sum of the energy output loss rate and the intrinsic loss rate of the system.

2. The desktop AGV wireless charging system as described in claim 1, characterized in that, All the non-resonant coils at the transmitting end have the same specifications, and all the resonant coils at the receiving end have the same specifications.

3. The desktop AGV wireless charging system as described in claim 2, characterized in that, The non-resonant coil at the transmitting end is a long strip coil, and the size of the non-resonant coil at the transmitting end is larger than the size of the resonant coil at the receiving end.

4. The desktop AGV wireless charging system as described in claim 2, characterized in that, The receiving end resonant coil is a square coil.

5. The desktop AGV wireless charging system as described in claim 1, characterized in that, The AGV workbench is covered with bakelite for winding the non-resonant coil of the transmitter, and the bakelite has grooves on it according to the winding method of the non-resonant coil of the transmitter.

6. The desktop AGV wireless charging system as described in claim 1, characterized in that, The transmitter module also includes a transmitter circuit, the input of which is connected to a power supply and the output of which is connected to the transmitter coil group.

7. The desktop AGV wireless charging system as described in claim 6, characterized in that, The transmitting circuit includes a first rectifier circuit, a first voltage adjustment circuit, and an inverter circuit connected in sequence. The first rectifier circuit is connected to the power supply, and the inverter circuit is connected to the transmitting coil group.

8. The desktop AGV wireless charging system as described in claim 1, characterized in that, The receiving module also includes a receiving circuit, the input of which is connected to the receiving resonant coil and the output of which is connected to the AGV load.

9. The desktop AGV wireless charging system as described in claim 8, characterized in that, The receiving circuit includes a second rectifier circuit and a second voltage adjustment circuit connected in sequence. The second rectifier circuit is connected to the receiving resonant coil, and the second voltage adjustment circuit is connected to the AGV load.

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