Self-moving device

Abstract

This invention discloses a self-moving device, comprising: a cutting component for cutting vegetation; a main body for supporting the cutting component; and a walking system for moving the main body. The walking system includes at least: walking wheels; a hub motor integrated within the walking wheels; and a control circuit for controlling the operation of the hub motor. The control circuit includes: a drive circuit comprising multiple switching elements for driving the hub motor; a detection circuit for acquiring the operating parameters of the hub motor; and a controller connected to the drive circuit, which outputs control signals based on the operating parameters to change the conduction state of the switching elements and control the hub motor speed to be greater than or equal to 8 rpm. By integrating the motor into the hub and implementing a low-speed control closed-loop design for the hub motor, the overall size and weight of the device are reduced, the low-speed control strategy is simplified, and the speed adjustment accuracy is high.

Description

Technical Field

[0001] This application relates to the field of mechanical control technology, and more particularly to a self-moving device. Background Technology

[0002] With the development of automatic control technology, intelligent equipment has been widely adopted in fields such as home life and industrial production. Intelligent lawnmowers, as intelligent robots integrating autonomous movement and mowing functions, have greatly improved the efficiency of garden and urban green space maintenance.

[0003] Existing smart lawnmowers typically house both the drive motor and the mowing motor within the outer casing. The built-in drive motor propels the wheels via a gear drive mechanism and other drive components. However, existing smart lawnmowers suffer from the following problems: they are bulky, and the drive components between the drive motor and the wheels increase the weight and installation complexity. In garden landscaping scenarios, the lawnmower travels at low speeds, and the complex low-speed control algorithms increase hardware costs. Furthermore, the large size and weight of the lawnmower make it inconvenient to use and move, negatively impacting the user experience. Summary of the Invention

[0004] This application provides a self-moving device to solve the problems of existing smart lawnmowers being large in size, heavy in weight, and having complex low-speed control strategies, thereby reducing the overall size of the machine and simplifying the low-speed control strategy.

[0005] According to one aspect of this application, a self-moving device is provided, comprising: a cutting component for cutting vegetation; a main body for supporting the cutting component; and a walking system for moving the main body. The walking system includes at least: a walking wheel; a hub motor integrated within the walking wheel; and a control circuit for controlling the operating state of the hub motor. The control circuit includes: a drive circuit comprising: a plurality of switching elements for driving the hub motor to operate; a detection circuit for acquiring the operating parameters of the hub motor; and a controller connected to the drive circuit, which outputs a control signal according to the operating parameters to change the conduction state of the switching elements and control the rotational speed of the hub motor to be greater than or equal to 8 rpm.

[0006] Optionally, the control circuit is an FOC control circuit, which includes at least a current loop circuit and a speed loop circuit; the current loop circuit is used to perform closed-loop regulation of the motor current or output torque of the hub motor; the speed loop circuit is used to perform closed-loop regulation of the motor speed of the hub motor.

[0007] Optionally, the operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, wherein the current parameters are continuously changing smooth parameters; the current parameters are determined based on the rotor position parameters of the hub motor.

[0008] Optionally, the detection accuracy of the rotor position parameter is less than or equal to 2.3°.

[0009] Optionally, the estimation accuracy of the rotor position parameters is greater than or equal to 0.01°.

[0010] Optionally, the number of pole pairs of the hub motor is greater than or equal to 26 pairs.

[0011] Optionally, the mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

[0012] According to another aspect of this application, a self-moving device is provided, comprising: a cutting component for cutting vegetation; a main body for supporting the cutting component; and a walking system for moving the main body. The walking system includes at least: a walking wheel; a hub motor integrated within the walking wheel; and a control circuit for controlling the operating state of the hub motor. The control circuit includes: a drive circuit comprising: a plurality of switching elements for driving the hub motor; a detection circuit for acquiring the operating parameters of the hub motor; and a controller connected to the drive circuit, which outputs a control signal according to the operating parameters to change the conduction state of the switching elements and control the walking speed of the walking wheel to be greater than or equal to 0.1 m / s. The diameter of the hub motor is greater than or equal to 18 cm and less than or equal to 33 cm.

[0013] Optionally, the control circuit is an FOC control circuit, which includes at least a current loop circuit and a speed loop circuit; the current loop circuit is used to perform closed-loop regulation of the motor current or output torque of the hub motor; the speed loop circuit is used to perform closed-loop regulation of the motor speed of the hub motor.

[0014] Optionally, the operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, wherein the current parameters are continuously changing smooth parameters; the current parameters are determined based on the rotor position parameters.

[0015] Optionally, the detection accuracy of the rotor position parameter is less than or equal to 2.3°.

[0016] Optionally, the estimation accuracy of the rotor position parameters is greater than or equal to 0.01°.

[0017] Optionally, the number of pole pairs of the hub motor is greater than or equal to 26 pairs.

[0018] Optionally, the mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

[0019] The technical solution of this application embodiment includes a walking wheel, a hub motor, and a control circuit. By integrating the hub motor into the walking wheel, the control circuit includes a drive circuit, a detection circuit, and a controller. The detection circuit acquires the operating parameters of the hub motor, and the controller outputs a control signal based on the operating parameters to change the conduction state of the switching element, controlling the speed of the hub motor to be greater than or equal to 8 rpm. By integrating the motor into the hub and implementing a low-speed control closed-loop design for the hub motor, the problems of large size, heavy weight, and complex low-speed control strategies in existing intelligent lawnmowers are solved. This helps to reduce the overall size and weight of the machine, simplify the low-speed control strategy, save hardware costs, and improve the speed adjustment accuracy.

[0020] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the structure of a self-moving device provided in this application;

[0023] Figure 2 for Figure 1 A top view of the internal mounting structure of the self-moving device in the image;

[0024] Figure 3 This application provides a schematic diagram of the structure of a hub motor;

[0025] Figure 4 A schematic diagram of the mounting structure of a hub motor provided in this application;

[0026] Figure 5 A cross-sectional view of the output shaft of a hub motor provided in this application;

[0027] Figure 6 A cross-sectional view of another hub motor output shaft provided in this application;

[0028] Figure 7 A cross-sectional view of the output shaft of another hub motor provided in this application;

[0029] Figure 8 for Figure 4 Assembly diagram of the hub motor in the vehicle;

[0030] Figure 9 for Figure 8 Cross-sectional view;

[0031] Figure 10 for Figure 9 A magnified view of part I in the image;

[0032] Figure 11 A schematic diagram of another hub motor mounting structure provided in this application;

[0033] Figure 12 for Figure 11 Assembly diagram of the hub motor in the vehicle;

[0034] Figure 13 for Figure 12 Cross-sectional view;

[0035] Figure 14 A schematic diagram of a walking system for a self-moving device provided in this application;

[0036] Figure 15 This application provides a control block diagram of an FOC control circuit for a self-moving device. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Figure 1This application provides a schematic diagram of the structure of a self-moving device. Figure 2 for Figure 1 The diagram shows a top view of the internal installation structure of the self-moving device. This embodiment is applicable to miniaturized, lightweight smart mobile devices that can be used to perform outdoor tasks, such as mowing lawns, weeds, and other vegetation. In this embodiment, the self-moving device 1 can be a smart lawnmower, which can automatically perform vegetation mowing operations without human intervention.

[0040] like Figure 1 and Figure 2 As shown, the self-moving device 1 includes: a cutting component 10 for cutting vegetation; a main body 20 for supporting the cutting component 10; and a walking system 30 for moving the main body 20. In this embodiment, the main body 20 includes a housing and a chassis mechanism for protecting the self-moving device 1, the chassis mechanism being used to fix and support the cutting component 10.

[0041] like Figure 2 As shown, the cutting assembly 10 may include a cutting motor 101 and a cutting part, wherein the cutting motor 101 drives the cutting part to perform vegetation cutting operations.

[0042] like Figure 2 As shown, the walking system 30 includes at least: walking wheels 301; hub motors 302 integrated within the walking wheels 301; and a control circuit 100 for controlling the operation of the hub motors 302. In this embodiment, the self-moving device 1 can be equipped with two driving wheels and one driven wheel. The hub motors 302 can be integrated into the driving wheels on both sides, meaning that the walking wheels 301 with integrated hub motors 302 can be placed on both sides of the self-moving device 1. When the self-moving device 1 is working, the hub motors 302 drive the walking wheels 301 to rotate using a direct drive method. The hub motors 302 output a specific power, driving the walking wheels 301 to rotate at an angle matching the output power, thereby realizing the movement control of the self-moving device 1.

[0043] Reference Figure 2 As shown, in the axial direction X along the walking wheel 301, the first external dimension L1 of the self-moving device 1 satisfies: greater than or equal to 0.2 meters and less than or equal to 1.5 meters; and in the direction Y perpendicular to the axial direction of the walking wheel 301, the second external dimension L2 of the self-moving device 1 satisfies: greater than or equal to 0.5 meters and less than or equal to 1.5 meters.

[0044] Reference Figure 2As shown, in the axial direction X along the traveling wheel, the first interval between the cutting motor 101 and the hub motor 302 is greater than zero and less than half of the first external dimension L1; in the direction Y perpendicular to the axial direction of the traveling wheel 301, the second interval between the cutting motor 101 and the hub motor 302 is greater than or equal to zero and less than the second external dimension L2.

[0045] The first interval between the cutting motor 101 and the hub motor 302 refers to the distance between the central axis of the cutting motor 101 and the end face of the hub motor 302 facing the cutting motor 101; the second interval between the cutting motor 101 and the hub motor 302 refers to the distance between the central axis of the cutting motor 101 and the central axis of the hub motor 302.

[0046] In this embodiment, the first external dimension L1 of the self-moving device 1 can be used to represent the maximum overall width of the self-moving device 1. Typically, the first external dimension L1 can be the spacing between the outer end faces of the two hub motors 302. The second external dimension L2 can be used to represent the maximum overall length of the self-moving device 1. Typically, the second external dimension L2 can be the spacing between the front end face and the rear end face of the self-moving device 1. Without changing the original design dimensions of the main body 20, the dimensions of the hub motors 302 and the output shaft of the hub motors 302 are matched with the overall width and overall length of the self-moving device 1.

[0047] Specifically, taking a smart lawnmower as an example, the width of the self-moving device 1 in the axial direction X is 0.2 meters to 1.5 meters, and the length of the self-moving device 1 in the vertical direction Y is 0.5 meters to 1.5 meters. The hub motor 302 replaces the original walking motor arranged in the main body 20. The hub motor 302 is detachably assembled into the walking wheel 301. The hub motor 302 directly drives the walking wheel 301 to rotate, eliminating the need for the gearbox and other structures between the walking motor and the walking wheel, which helps to reduce the overall size and weight of the machine.

[0048] Optionally, the distance between the outer end faces of the hub motors 302 in this application is greater than the cutting width of the cutting assembly 10. Specifically, two wheels 301 integrating hub motors 302 can be symmetrically arranged on both sides of the self-moving device 1. The distance between the outer end faces of the hub motors 302 on both sides is greater than the cutting width of the cutting assembly 10, which is beneficial to improving the cutting quality and achieving safety protection.

[0049] Optionally, the hub motor 302 can rotate at a speed greater than or equal to 8 rpm, enabling low-speed driving.

[0050] Optionally, the output power of the hub motor 302 is greater than or equal to 1W. In this embodiment, the output power of the hub motor 302 can be adjusted according to the actual working conditions. For example, under flat ground walking conditions, the output power of the hub motor 302 is approximately 2.5W to 3W; under climbing conditions, the output power of the hub motor 302 can be 15W.

[0051] Optionally, the hub motor 302 of this application adopts a flat structure. The external dimensions of the hub motor 302 match the external dimensions and installation position of the traveling wheel 301. Since the traveling wheel 301 has a flat structure and the gap between the traveling wheel 301 and the housing of the main body 20 is small, the flat hub motor 302 is conducive to adapting to the original external structure of the self-moving device 1.

[0052] Figure 3 This is a schematic diagram of the structure of a hub motor provided in this application.

[0053] like Figure 3 As shown, the radial length D of the hub motor 302 can be greater than or equal to 18 cm and less than or equal to 33 cm; the axial thickness d of the hub motor 302 is less than or equal to 3.5 cm. By adjusting the radial length D and axial thickness d of the hub motor, the hub motor 302 can be made into a flat structure, which can be directly adapted to the original shape structure of the self-moving device 1, avoiding changes to the body shell caused by replacing the motor, and has strong structural versatility.

[0054] Alternatively, the hub motor 302 may be made of materials such as aluminum, plastic or steel.

[0055] Optionally, the energy density of the hub motor 302 satisfies: greater than or equal to 0.05 W / cm². 3 And less than or equal to 0.5 W / cm 3 The energy density of the motor refers to the ratio between the maximum output power of the hub motor 302 and the weight, volume, or area of ​​the entire hub motor 302 or the self-moving device 1. The higher the energy density of the hub motor 302, the stronger its driving capability. Increasing the energy density of the hub motor helps ensure the driving capability of miniaturized and lightweight self-moving devices.

[0056] Optionally, the heat dissipation area of ​​the hub motor 302 can meet the following requirement: 50cm² 2 Up to 300cm 2The heat dissipation area of ​​the hub motor 302 refers to the surface area of ​​the winding portion of the stator winding of the hub motor 302. In this embodiment, the heat dissipation area of ​​the motor can be optimized by adjusting the number of turns, wire diameter, or winding density of the stator winding. While implementing a flattened design for the hub motor 302, the heat dissipation capacity of the hub motor 302 is improved, which is beneficial to improving the working efficiency of the hub motor 302, improving the performance of the hub motor, and enhancing the driving capability of the self-moving equipment.

[0057] Optionally, the slot fill factor of the hub motor 302 satisfies a value greater than 45%. Here, slot fill factor refers to the proportion of space occupied by the stator windings of the hub motor 302 after they are placed in the electrode slots. In this embodiment, the slot fill factor of the hub motor 302 can be adjusted by reducing the thickness of the insulation material or changing the number of wires wound. By increasing the slot fill factor of the hub motor 302, the copper loss and temperature rise of the motor are reduced, which helps to improve the working efficiency of the hub motor 302, improve its performance, and enhance the driving capability of the self-moving equipment.

[0058] It should be noted that, in this application, the slot fill factor of the hub motor 302 is also matched with the power supply voltage of the hub motor 302.

[0059] Optionally, the number of magnetic pole pairs of the hub motor 302 satisfies: greater than or equal to 26 pairs; or, the mechanical angle between any two adjacent magnetic poles of the hub motor 302 is less than or equal to 6.9°, thereby improving the accuracy of motor rotor position detection.

[0060] Optionally, the hub width of the hub motor 302 is positively correlated with the overall weight of the self-moving device 1 to match the needs of different devices and different working conditions, provide motor adaptability, and facilitate the simplification of assembly process.

[0061] In one embodiment, when the weight of the whole machine is greater than or equal to 10 kg and less than or equal to 20 kg, the wheel hub width satisfies the following: greater than or equal to 3 cm and less than or equal to 4 cm; when the weight of the whole machine is greater than 20 kg and less than or equal to 40 kg, the wheel hub width satisfies the following: greater than 4 cm and less than or equal to 6 cm; when the weight of the whole machine is greater than 40 kg and less than or equal to 60 kg, the wheel hub width satisfies the following: greater than 6 cm and less than or equal to 9 cm.

[0062] Therefore, by adjusting the external dimensions and arrangement of the hub motor 302, this application integrates the hub motor 302 into the walking wheel. Along the axial direction of the walking wheel, the first external dimension of the self-moving device is controlled within the range of 0.2 meters or more and 1.5 meters or less. And along the direction perpendicular to the axial direction of the walking wheel, the second external dimension of the self-moving device is controlled within the range of 0.5 meters or more and 1.5 meters or less. The drive method between the hub motor 302 and the walking wheel is direct drive, eliminating the need for drive components such as gearboxes. The overall structure is compact, solving the problems of large size and heavy weight of existing intelligent lawnmowers. This helps save internal space, improve space utilization, reduce overall size and weight, and enhance the user experience.

[0063] Figure 4 This is a schematic diagram of the mounting structure of a hub motor provided in this application. Figure 1 Based on the illustrated embodiment, a specific implementation is shown whereby a hub motor is fixed to the housing of the main body 20 via a connector.

[0064] like Figure 4 As shown, the self-moving device 1 also includes a connector 40, which includes a mounting hole 401, a first end face facing the side of the walking wheel 301 and a second end face facing away from the side of the walking wheel 301. The inner diameter of the mounting hole 401 is matched with the outer diameter of the output shaft 303 of the hub motor 302. The connector 40 is used to detachably mount the hub motor 302 onto the housing of the main body 20.

[0065] In this embodiment, the inner diameter of the mounting hole 401 can be set to be larger than the outer diameter of the output shaft 303 of the hub motor 302, and the inner diameter of the output shaft 303 of the hub motor 302 is larger than the motor cable diameter * motor cable harness.

[0066] For example, the output shaft of the hub motor 302 can be configured to have an outer diameter greater than 8 mm and an inner diameter greater than 4 mm and less than 7 mm.

[0067] like Figure 4 As shown, a connector mounting hole 201 is provided on the housing of the main body 20. During the assembly process, the output shaft 303 of the hub motor 302 is first inserted through the mounting hole 401 of the connector 40, and the second end face of the connector 40 passes through the connector mounting hole 201. The hub motor 302 is detachably mounted on the housing of the main body 20 through the connector 40.

[0068] In one embodiment, a limiting mechanism is provided between the output shaft 303 of the hub motor 302 and the connector 40. The limiting mechanism is used to limit the relative displacement between the output shaft and the connector 40. The relative displacement includes axial displacement and / or circumferential displacement. That is, the limiting mechanism includes a limiting mechanism for limiting axial displacement between the output shaft and the connector 40, and / or a limiting mechanism for limiting circumferential displacement between the output shaft and the connector 40.

[0069] like Figure 4 As shown, the limiting mechanism between the output shaft 303 of the hub motor 302 and the connector 40 can be at least one platform portion. The platform portion extends along the axial direction X and is disposed in at least a portion of the output shaft 303 and the connector 40. The platform portion can be used to limit circumferential displacement between the output shaft and the connector 40. In this embodiment, the platform portion includes at least a first platform portion 303A disposed on the output shaft 303 and a second platform portion 401A disposed in the mounting hole 401. Both the first platform portion 303A and the second platform portion 401A extend along the axial direction X, and the width of the first platform portion 303A matches the width of the second platform portion 401A. During assembly, the first platform portion 303A and the second platform portion 401A are aligned, and the output shaft 303 is inserted through the mounting hole 401 of the connector 40. The first platform portion 303A and the second platform portion 401A of the connector 40 cooperate with each other to limit circumferential displacement between the output shaft and the connector 40, which helps to improve assembly reliability.

[0070] It should be noted that one or more first platform portions 303A can be formed on the output shaft 303 by metal cutting process. Under the premise of ensuring that the first platform portion 303A and the second platform portion 401A are matched and assembled, there are no restrictions on the axial length, width and number of the first platform portion 303A and the second platform portion 401A.

[0071] Optionally, Figure 5 A cross-sectional view of the output shaft of a hub motor provided in this application.

[0072] like Figure 5 As shown, the limiting mechanism may include at least one stepped portion 303B and at least one recessed portion 303C disposed on the output shaft 303 of the hub motor 302. In this embodiment, the stepped portion 303B can act as a block, and when the stepped portion 303B contacts the connector 40, the output shaft 303 of the hub motor 302 cannot continue to penetrate into the mounting hole 401 of the connector 40; at this time, by cooperating with the limiting member to install the recessed portion 303C, axial displacement between the output shaft and the connector 40 can be restricted.

[0073] It should be noted that the limiting mechanism may also include a stepped portion disposed on the connector 40, which has the same function as the stepped portion disposed on the output shaft 303, and will not be described in detail here.

[0074] Optionally, Figure 6 A cross-sectional view of another hub motor output shaft provided in this application.

[0075] like Figure 6 As shown, the limiting mechanism may include at least one protrusion disposed on the output shaft 303 of the hub motor 302. In this embodiment, a fixed protrusion 303D may be provided on the side of the output shaft 303 near the hub motor 302, and a resettable protrusion 303D' may be provided on the side of the output shaft 303 away from the hub motor 302. The interval between the fixed protrusion 303D and the resettable protrusion 303D' matches the depth of the mounting hole 401 of the connector 40. During assembly, when the resettable protrusion 303D' enters the mounting hole 401 of the connector 40, the resettable protrusion 303D' is compressed, and the output shaft 303 continues to penetrate deeper into the mounting hole 401 until the fixed protrusion 303D contacts the connector 40. The resettable protrusion 303D' then pops out, and the fixed protrusion 303D and the resettable protrusion 303D' cooperate with each other to restrict axial displacement between the output shaft and the connector 40.

[0076] It should be noted that the protrusions can be square, rectangular, triangular or semi-circular in shape. Those skilled in the art can adjust the shape, size and number of the protrusions according to the processing difficulty, and there are no limitations on this.

[0077] Optionally, Figure 7 A cross-sectional view of the output shaft of another hub motor provided in this application.

[0078] like Figure 7 As shown, the limiting mechanism may include at least one radial dimension gradient portion 303E. In this embodiment, the radial dimension gradient portion 303E may be a portion of the output shaft 303 of the hub motor 302 that has a front-narrowing and rear-thickening structure. Correspondingly, the mounting hole 401 of the connector 40 also has a front-narrowing and rear-thickening structure. The minimum radial dimension of the radial dimension gradient portion 303E is smaller than the minimum radial dimension of the mounting hole 401, and the maximum radial dimension of the radial dimension gradient portion 303E is larger than the maximum radial dimension of the mounting hole 401. During assembly, the output shaft 303 is gradually inserted into the mounting hole 401 until the radial dimension of the output shaft 303 is larger than the radial dimension of the mounting hole 401, at which point the output shaft 303 of the hub motor 302 can no longer be inserted into the mounting hole 401 of the connector 40. Furthermore, the radial dimension gradient portion 303E may cooperate with the groove portion 303C and the limiting member to restrict axial displacement between the output shaft 303 and the connector 40.

[0079] Optionally, Figure 8 for Figure 4 Assembly diagram of the hub motor in the vehicle; Figure 9 for Figure 8 Cross-sectional view; Figure 10 for Figure 9 A magnified view of part I in the image.

[0080] like Figure 4 , Figures 8 to 10 As shown, the limiting mechanism also includes an end face limiting member 402, which is disposed on the second end face of the connector 40 and is engaged and fixed with the first groove 303C' of the output shaft 303. The first groove 303C' is located at the projection of the second end face of the connector 40 onto the output shaft 303.

[0081] Specifically, the end face limiting member 402 can be a retaining ring or a clamp. The retaining ring is provided with a fastening part for adjusting the clamping pressure. After the first groove 303C' of the output shaft 303 extends out of the mounting hole 401 of the connector 40, the end face limiting member 402 is snapped into the first groove 303C' and fixed to the output shaft 303 by the fastening part to prevent the output shaft 303 from axially moving.

[0082] Reference Figure 9 and Figure 10 As shown, the self-moving device 1 further includes a sealing mechanism, which includes at least a first sealing mechanism 501. The first sealing mechanism 501 is disposed on the side of the output shaft near the first end face, and the first sealing mechanism 501 is used to seal the contact surface between the connector 40 and the output shaft 303.

[0083] Specifically, the first sealing mechanism 501 can be a skeleton oil seal. The first sealing mechanism 501 fills the gap between the connector 40 and the output shaft 303, which can prevent liquid or dust from entering the machine body through the output shaft 303, thereby improving the sealing performance of the equipment and increasing the reliability of the equipment.

[0084] Reference Figure 9 As shown, the sealing mechanism further includes a second sealing mechanism 502, which is disposed between the connector 40 and the body housing of the main body 20. The second sealing mechanism 502 is used to seal the contact surface between the connector 40 and the body housing.

[0085] Specifically, the second sealing mechanism 502 can be a rubber ring. The second sealing mechanism 502 is installed between the connector 40 and the body housing of the main body 20 to prevent liquid or dust from entering the equipment through the connector 40, thereby improving the sealing performance of the equipment and increasing its reliability.

[0086] Optionally, Figure 11A schematic diagram of another hub motor mounting structure provided in this application; Figure 12 for Figure 11 Assembly diagram of the hub motor in the vehicle; Figure 13 for Figure 12 The cross-sectional view in this embodiment shows another specific implementation of fixing the hub motor 302 to the housing of the main body 20 by means of a connector.

[0087] like Figures 11 to 13 As shown, the limiting mechanism also includes a rigid limiting member 403, which is detachably fixed to the outer shell of the main body 20 via the mounting assembly, and the rigid limiting member 403 is snapped and fixed to the output shaft 303.

[0088] Specifically, the rigid limiting member 403 can be a steel plate, and the stopping force of the steel plate is greater than that of the retaining ring. The mounting assembly includes screw posts and reinforcing ribs provided on the main body 20. After the output shaft 303 is assembled into the limiting position of the mounting hole 401, the end face limiting member 402 is locked and fixed to the output shaft 303 by the symmetrical screw posts and reinforcing ribs on both sides to prevent the output shaft 303 from axially moving.

[0089] In this embodiment, a platform portion (i.e., a flat structure) can be provided on the output shaft 303 of the hub motor 302, and a groove matching the platform portion can be provided on the rigid limiting member 403, which is beneficial for the installation of the rigid limiting member 403 and improves the structural reliability.

[0090] In this embodiment, a second groove can also be provided on the protrusion of the output shaft 303 extending beyond the mounting hole 401, and the end face limiting member 402 can be embedded in the second groove to improve structural reliability.

[0091] Reference Figures 11 to 13 As shown, in this embodiment, the self-moving device 1 may be equipped with a first sealing mechanism 501 and / or a second sealing mechanism 502, etc., to prevent liquid or dust from entering the device through the connector 40 and the output shaft 303 of the hub motor 302, etc., which helps to improve the sealing performance of the device and improve the reliability of the device.

[0092] Reference Figures 5 to 7 As shown, in this embodiment, a limiting mechanism can be provided between the output shaft 303 of the hub motor 302 and the connecting member 40 to limit axial and circumferential displacement between the output shaft and the connecting member 40. In this embodiment, the specific implementation method and beneficial effects of the limiting mechanism are the same as those described in the above embodiments, and will not be repeated here.

[0093] Based on any of the above embodiments, this application also provides a hub motor for a self-moving device, the self-moving device including a walking wheel, the hub motor being integrated within the walking wheel.

[0094] Reference Figure 3 As shown, the radial length of the hub motor meets the following requirements: greater than or equal to 18 cm and less than or equal to 33 cm; the axial thickness of the hub motor meets the following requirement: less than or equal to 3.5 cm.

[0095] Alternatively, the hub motor 302 may be made of materials such as aluminum, plastic or steel.

[0096] Optionally, the energy density of the hub motor 302 satisfies: greater than or equal to 0.05 W / cm². 3 And less than or equal to 0.5 W / cm 3 The energy density of the motor refers to the ratio between the maximum output power of the hub motor 302 and the weight, volume, or area of ​​the entire hub motor 302 or the self-moving device 1. The higher the energy density of the hub motor 302, the stronger its driving capability. Increasing the energy density of the hub motor helps ensure the driving capability of miniaturized and lightweight self-moving devices.

[0097] Optionally, the heat dissipation area of ​​the hub motor 302 can meet the following requirement: 50cm² 2 Up to 300cm 2 The heat dissipation area of ​​the hub motor 302 refers to the surface area of ​​the winding portion of the stator winding of the hub motor 302. In this embodiment, the heat dissipation area of ​​the motor can be optimized by adjusting the number of turns, wire diameter, or winding density of the stator winding. While implementing a flattened design for the hub motor 302, the heat dissipation capacity of the hub motor 302 is improved, which is beneficial to improving the working efficiency of the hub motor 302, improving the performance of the hub motor, and enhancing the driving capability of the self-moving equipment.

[0098] Optionally, the slot fill factor of the hub motor 302 satisfies a value greater than 45%. Here, slot fill factor refers to the proportion of space occupied by the stator windings of the hub motor 302 after they are placed in the electrode slots. In this embodiment, the slot fill factor of the hub motor 302 can be adjusted by reducing the thickness of the insulating material or changing the number of wires wound. By increasing the slot fill factor of the hub motor 302, the copper loss and temperature rise of the motor are reduced, which helps to improve the working efficiency of the hub motor 302, improve its performance, and enhance the driving capability of the self-moving equipment. It should be noted that in this application, the slot fill factor of the hub motor 302 is also matched with the supply voltage of the hub motor 302.

[0099] Optionally, the number of magnetic pole pairs of the hub motor 302 satisfies: greater than or equal to 26 pairs; or, the mechanical angle between any two adjacent magnetic poles of the hub motor 302 is less than or equal to 6.9°, which is beneficial to improving the accuracy of motor rotor position detection.

[0100] Optionally, the hub width of the hub motor 302 is positively correlated with the overall weight of the self-moving device 1 to match the needs of different devices and different working conditions, provide motor adaptability, and facilitate the simplification of assembly process.

[0101] In one embodiment, when the weight of the whole machine is greater than or equal to 10 kg and less than or equal to 20 kg, the wheel hub width satisfies the following: greater than or equal to 3 cm and less than or equal to 4 cm; when the weight of the whole machine is greater than 20 kg and less than or equal to 40 kg, the wheel hub width satisfies the following: greater than 4 cm and less than or equal to 6 cm; when the weight of the whole machine is greater than 40 kg and less than or equal to 60 kg, the wheel hub width satisfies the following: greater than 6 cm and less than or equal to 9 cm.

[0102] Optionally, the hub motor 302 can rotate at a speed greater than or equal to 8 rpm, enabling low-speed travel of the self-moving device.

[0103] Optionally, the output power of the hub motor 302 is greater than or equal to 1W. In this embodiment, the output power of the hub motor 302 can be adjusted according to the actual working conditions. For example, under flat ground walking conditions, the output power of the hub motor 302 is approximately 2.5W to 3W; under climbing conditions, the output power of the hub motor 302 can be 15W.

[0104] Therefore, by adjusting the external dimensions and arrangement of the hub motor 302, this application integrates the hub motor 302 into the walking wheel. The drive method between the hub motor 302 and the walking wheel is a direct drive method, eliminating the need for drive components such as gearboxes. It can be directly adapted to the original external structure of the self-moving device 1, avoiding changes to the body shell caused by replacing the motor. The structure has strong versatility, which helps to simplify the motor assembly process and save production costs.

[0105] Based on the same concept, this application also provides a self-moving device. In addition to the self-moving device of any of the above embodiments, a low-speed control closed-loop design for the motor is added to the walking system, which can simplify the low-speed control strategy and improve the accuracy of motor speed regulation.

[0106] Figure 14 This application provides a schematic diagram of a walking system for a self-moving device.

[0107] like Figure 14As shown, the control circuit 100 includes: a drive circuit 110, which includes: multiple switching elements, typically including a first switching element Q1, a second switching element Q2, a third switching element Q3, a fourth switching element Q4, a fifth switching element Q5, and a sixth switching element Q6, wherein the first switching element Q1 to the sixth switching element Q6 form a full-bridge circuit for driving the hub motor 302 to operate; a detection circuit 120 for acquiring the operating parameters of the hub motor 302; and a controller 130 connected to the drive circuit 110, which outputs a control signal according to the operating parameters to change the conduction state of the switching elements and control the speed of the hub motor 302 to be greater than or equal to 8 rpm.

[0108] It should be noted that intelligent lawnmowers with integrated hub motors on their wheels and a hub motor speed greater than or equal to 8 rpm are all within the scope of protection of this application. Alternatively, intelligent lawnmowers with integrated hub motors on their wheels and a walking speed greater than or equal to 0.1 m / s are also within the scope of protection of this application.

[0109] In this embodiment, the detection circuit 120 includes a speed and position estimation module and a current detection module. Typically, a Hall sensor can be used as the speed and position estimation module.

[0110] In one embodiment, the control circuit 100 is an FOC control circuit. The FOC control circuit refers to a circuit that performs closed-loop control of the rotational speed of the hub motor 302 using a vector control strategy.

[0111] Figure 15 This application provides a control block diagram of an FOC control circuit for a self-moving device.

[0112] like Figure 15 As shown, the FOC control circuit includes at least a current loop circuit and a speed loop circuit. Of course, the FOC control circuit may also include a position loop circuit. The current loop circuit is used to perform closed-loop regulation of the motor current or output torque of the hub motor 302. The speed loop circuit is used to perform closed-loop regulation of the motor speed of the hub motor 302.

[0113] Specifically, combined Figure 15 As shown, the speed loop circuit can influence the input parameters of the current loop circuit. In other words, the speed loop circuit adds a PI loop before the current loop circuit to obtain an input parameter for the current loop circuit based on preset speed parameters and the actual rotational speed of the hub motor 302. and In the current loop circuit, the three-phase current (i) in the three-phase stator coordinate system is first obtained based on current sampling. a i b i cThen, the control current of the hub motor 302 is vector decomposed, and based on Clark transformation, the three-phase currents (i) in the three-phase stator coordinate system are decomposed. a i b i c Converted to current parameters in a two-phase stator coordinate system. and Furthermore, based on the Park transformation, the current parameters in the two-phase stator coordinate system are... and Convert the current parameters (i) to the dq coordinate system. d i q Furthermore, the sampling PI controller samples the current parameters (i) in the dq coordinate system. d i q The output deviation is adjusted using a closed-loop control, and the voltage parameters in the dq coordinate system are output. and Furthermore, the voltage parameters in the dq coordinate system are transformed using the inverse Park transformation. and Converted to voltage parameters in a two-phase stator coordinate system. and Finally, the three-phase voltage parameters (u) in the three-phase stator coordinate system are calculated based on a PWM wave modulation algorithm (e.g., SVPWM algorithm). a u b u c This enables vector control of the hub motor 302. Therefore, by setting up a current loop circuit and a speed loop circuit, a dual closed-loop control system for speed and current is formed.

[0114] Optionally, the operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, and the current parameters are continuously changing smooth parameters; the current parameters are determined based on the rotor position parameters of the hub motor.

[0115] Optionally, the detection accuracy of the rotor position parameters shall be less than or equal to 2.3°.

[0116] Optionally, the estimation accuracy of the rotor position parameters satisfies the condition of being greater than or equal to 0.01°. In this embodiment, the estimation accuracy of the rotor position parameters is positively correlated with the motor speed of the hub motor 302. When the motor speed of the hub motor 302 is 40 rpm, the rotor position estimation accuracy is 0.012°, and when the motor speed is around 8 rpm, the rotor position estimation accuracy may be around 0.01°.

[0117] Optionally, the hub motor 302 has a pole pair number greater than or equal to 26 pairs. In this embodiment, the estimation accuracy of the rotor position parameters is negatively correlated with the number of pole pairs. When the number of pole pairs of the hub motor 302 is equal to 26 pairs, the detection accuracy of the rotor position parameters is 2.3°. As the number of pole pairs increases, the detection accuracy of the rotor position parameters will be less than 2.3°.

[0118] Optionally, the mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

[0119] Specifically, a Hall effect sensor can be used to detect the rotor position, with a detection angle greater than or equal to 6.9°. When the number of pole pairs in the hub motor 302 is 26, the mechanical angle between the poles is 6.9°. The rotor angular velocity is calculated within a detection angle range (i.e., 6.9°). At any point within the next 6.9° range, the rotor position can be calculated based on the angular velocity. However, at inflection points, the estimated rotor position is updated based on the rotor position detected by the Hall effect sensor, ensuring that the rotor position provided by the Hall effect sensor is continuously changing, and consequently, the current parameters obtained based on the rotor position are also continuously changing.

[0120] Therefore, the technical solution of this application embodiment includes a walking wheel, a hub motor, and a control circuit. By integrating the hub motor into the walking wheel, and the control circuit including a drive circuit, a detection circuit, and a controller, the detection circuit acquires the operating parameters of the hub motor. The controller outputs a control signal based on the operating parameters to change the conduction state of the switching element, controlling the hub motor speed to be greater than or equal to 8 rpm. By integrating the motor into the hub and implementing a low-speed control closed-loop design for the hub motor, the problems of large size, heavy weight, and complex low-speed control strategies in existing intelligent lawnmowers are solved. This helps to reduce the overall size and weight of the machine, simplify the low-speed control strategy, reduce hardware costs, and improve speed adjustment accuracy.

[0121] Based on the same concept, this application also provides another self-moving device. Based on the self-moving device of any of the above embodiments, a low-speed control closed-loop design for the walking wheels is added to the walking system, which can simplify the low-speed control strategy and improve the speed adjustment accuracy of the device.

[0122] In this embodiment, the control circuit includes: a drive circuit comprising multiple switching elements for driving the hub motor; a detection circuit for acquiring the operating parameters of the hub motor; and a controller connected to the drive circuit, which outputs control signals according to the operating parameters to change the conduction state of the switching elements and control the walking speed of the wheel to be greater than or equal to 0.1 m / s; wherein the diameter of the hub motor is greater than or equal to 18 cm and less than or equal to 33 cm.

[0123] In one embodiment, the control circuit is an FOC control circuit. This FOC control circuit includes at least a current loop circuit and a speed loop circuit; the current loop circuit is used for closed-loop regulation of the motor current or output torque of the hub motor; the speed loop circuit is used for closed-loop regulation of the motor speed of the hub motor.

[0124] Optionally, the operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, and the current parameters are continuously changing smooth parameters; the current parameters are determined based on the rotor position parameters of the hub motor.

[0125] Optionally, the detection accuracy of the rotor position parameters shall be less than or equal to 2.3°.

[0126] Optionally, the estimation accuracy of the rotor position parameters satisfies the following condition: greater than or equal to 0.01°.

[0127] Optionally, the number of pole pairs of the hub motor is greater than or equal to 26 pairs.

[0128] Optionally, the mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

[0129] Therefore, the technical solution of this application embodiment includes a walking wheel, a hub motor, and a control circuit. By integrating the hub motor into the walking wheel, and the control circuit including a drive circuit, a detection circuit, and a controller, the detection circuit acquires the operating parameters of the hub motor. The controller outputs a control signal based on the operating parameters to change the conduction state of the switching element, controlling the walking wheel speed to be greater than or equal to 0.1 m / s. By integrating the motor into the hub and implementing a low-speed control closed-loop design for the walking wheel, the problem of existing intelligent lawnmowers being large, heavy, and having complex low-speed control strategies is solved. This helps to reduce the overall size and weight of the machine, simplify the low-speed control strategy, reduce hardware costs, and improve speed adjustment accuracy.

[0130] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0131] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A self-moving device, comprising: Cutting components for cutting vegetation; The main body is used to support the cutting assembly; A walking system is used to move the main body. The walking system is characterized in that it includes at least: Wheels; Hub motor, wherein the hub motor is integrated into the walking wheel; A control circuit is used to control the operating state of the hub motor; The control circuit includes: The drive circuit includes: multiple switching elements for driving the hub motor to operate; A detection circuit is used to acquire the operating parameters of the hub motor; The controller is connected to the drive circuit and outputs control signals according to the operating parameters to change the conduction state of the switching element and control the speed of the hub motor to be greater than or equal to 8 rpm, so as to realize the low-speed driving of the self-moving device. The hub motor has a pole pair number greater than or equal to 26 pairs; The control circuit is an FOC control circuit, which includes at least a current loop circuit and a speed loop circuit. The current loop circuit is used to perform closed-loop regulation of the motor current or output torque of the hub motor. The speed loop circuit is used to perform closed-loop regulation of the motor speed of the hub motor. The detection accuracy of the rotor position parameters of the hub motor is less than or equal to 2.3°.

2. The self-moving device according to claim 1, characterized in that, The operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, and the current parameters are continuously changing smooth parameters. The current parameters are determined based on the rotor position parameters of the hub motor.

3. The self-moving device according to claim 2, characterized in that, The estimation accuracy of the rotor position parameters is greater than or equal to 0.01°.

4. The self-moving device according to any one of claims 1-3, characterized in that, The mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

5. A self-moving device, comprising: Cutting components for cutting vegetation; The main body is used to support the cutting assembly; A walking system is used to move the main body. The walking system is characterized in that it includes at least: Wheels; Hub motor, wherein the hub motor is integrated into the walking wheel; A control circuit is used to control the operating state of the hub motor; The control circuit includes: The drive circuit includes: multiple switching elements for driving the hub motor to operate; A detection circuit is used to acquire the operating parameters of the hub motor; The controller is connected to the drive circuit and outputs control signals according to the operating parameters to change the conduction state of the switching element and control the walking speed of the walking wheel to be greater than or equal to 0.1m / s, so as to realize the low-speed travel of the self-moving device. The diameter of the hub motor is greater than or equal to 18 cm and less than or equal to 33 cm. The hub motor has a pole pair number greater than or equal to 26 pairs; The control circuit is an FOC control circuit, which includes at least a current loop circuit and a speed loop circuit. The current loop circuit is used to perform closed-loop regulation of the motor current or output torque of the hub motor. The speed loop circuit is used to perform closed-loop regulation of the motor speed of the hub motor. The detection accuracy of the rotor position parameters of the hub motor is less than or equal to 2.3°.

6. The self-moving device according to claim 5, characterized in that, The operating parameters include the current parameters fed back from the detection circuit to the current loop circuit, and the current parameters are continuously changing smooth parameters. The current parameters are determined based on the rotor position parameters.

7. The self-moving device according to claim 6, characterized in that, The estimation accuracy of the rotor position parameters is greater than or equal to 0.01°.

8. The self-moving device according to any one of claims 5-7, characterized in that, The mechanical angle between any two adjacent magnetic poles of the hub motor is less than or equal to 6.9°.

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