robotic lawnmower
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- SHENZHEN MAMMOTION INNOVATION CO LTD
- Filing Date
- 2024-09-11
- Publication Date
- 2026-07-23
Abstract
Description
lawn mowing robot
[0001] This application claims priority to the Chinese patent application number 202322476802.7, application name “Mowing Robot”, submitted to the China Patent Office on September 11, 2023, and the Chinese patent application number 202421385657X, application name “Mowing Robot”, the entire contents of which are incorporated by reference into this application. Technical Field
[0002] The present application relates to the field of robots, and in particular to a lawn mowing robot. Background Art
[0003] Existing robotic lawn mowers are generally rear-wheel driven, with the front wheels driven. These robots have no trouble navigating hardened roads. However, when navigating grass, the friction on grass is greater than on hardened roads, especially in areas with dense grass. Furthermore, the inner front wheel faces greater resistance when turning, making it prone to slipping. When slipping occurs, the rear-wheel drive system needs to provide greater torque to overcome friction, resulting in significant grass abrasion.
[0004] Summary of the Invention
[0005] In view of this, the present application provides a lawn mowing robot to solve the technical problem of the lawn mowing robot slipping when turning.
[0006] The lawn mowing robot provided by the present application includes a main body bracket, omnidirectional wheels, drive wheels, several drive motors and a drive control system; the main body bracket includes a first end and a second end; the first end and the second end are arranged opposite to each other; the omnidirectional wheel is arranged on the first end; the drive wheel is arranged on the second end; the rated power of the several drive motors is the same; the several drive motors are arranged corresponding to the omnidirectional wheels and the drive wheels; each of the drive motors is connected to the corresponding omnidirectional wheel and drives the omnidirectional wheel to rotate or is connected to the corresponding drive wheel and drives the drive wheel to rotate; the drive control system is used to connect to the several drive motors, and control the rotational speed of the omnidirectional wheel and the drive wheel by controlling the magnitude of the input current of each of the several drive motors.
[0007] Therefore, in the present application, the lawn mower robot adopts drive motors with the same rated power, and the drive control system can control the rotational speed of the omnidirectional wheels and the drive wheels by controlling the magnitude of the input current of each of the drive motors, forcing one or more of the sliding friction between the omnidirectional wheels and the drive wheels and the ground to be converted into rolling friction to avoid slipping, or adjust the respective rotational speeds and thus adjust the travel speed of the lawn mower robot when both the omnidirectional wheels and the drive wheels are not slipping with the ground, so as to overcome the resistance between the omnidirectional wheels and the drive wheels of the lawn mower robot and the ground and ensure the travel speed of the lawn mower robot. Even in places where the grass is deep and the resistance is relatively large, the lawn mower robot can move normally without slipping, thereby enhancing the mowing ability of the lawn mower robot and avoiding damaging the lawn. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0009] FIG1 is a top view of a lawn mowing robot in a first embodiment of the present application.
[0010] FIG2 is an exploded schematic diagram of the lawn mowing robot in the first embodiment of the present application.
[0011] FIG3 is a schematic diagram of modules of the lawn mowing robot in the first embodiment of the present application.
[0012] FIG4 is a schematic diagram of the three-dimensional structure of the connection between the front axle, the front drive motor and the omnidirectional wheel in the first embodiment of the present application.
[0013] FIG5 is a side view of the omnidirectional wheel in the first embodiment.
[0014] FIG6 is a schematic diagram of the three-dimensional structure of the connection between the rear axle, the rear drive motor and the drive wheel in the first embodiment of the present application.
[0015] FIG7 is a schematic diagram of the speed of the lawn mowing robot in the first embodiment of the present application when turning in place.
[0016] FIG8 is a top view of the lawn mower robot in the second embodiment of the present application when the central axis of the driving wheel is perpendicular to the symmetry axis of the lawn mower robot.
[0017] 9 is a top view of the lawn mower robot in the second embodiment of the present application when the central axis of the driving wheel intersects with but is not perpendicular to the symmetry axis of the lawn mower robot. DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0020] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. Similar words such as "one", "an", or "the" used in this application do not indicate a quantitative limitation, but are only used to indicate the existence of at least one. Similar words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connected" or connected are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
[0021] Throughout this specification, reference to terms such as "embodiment," "specific embodiment," and "example" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
[0022] Please refer to Figure 1, which is a top view of the lawn mower robot in the first embodiment of the present application. The lawn mower robot 1 is a robot that can automatically mow the lawn. Its working principle is to use built-in sensors to identify the contours and obstacles of the lawn and mow the lawn using a pre-set route.
[0023] Please refer to Figures 2 and 3. Figure 2 is an exploded schematic diagram of the lawn mower robot 1 according to the first embodiment of the present application; Figure 3 is a modular schematic diagram of the lawn mower robot 1 according to the first embodiment of the present application. The lawn mower robot 1 includes a main frame 11, omnidirectional wheels 12, drive wheels 13, multiple drive motors 14, and a drive control system 15. The main frame 11 includes a first end 111 and a second end 112. The first end 111 and the second end 112 are arranged opposite each other. The omnidirectional wheels 12 are disposed at the first end 111. The drive wheels 13 are disposed at the second end 112. The multiple drive motors 14 have the same rated power. The multiple drive motors 14 are respectively arranged to correspond to the omnidirectional wheels 12 and the drive wheels 13. Each drive motor 14 is connected to a corresponding omnidirectional wheel 12 and drives the rotation of the omnidirectional wheel 12, or is connected to a corresponding drive wheel 13 and drives the rotation of the drive wheel 13. The drive control system 15 is connected to the multiple drive motors 14 and controls the rotational speed of the omnidirectional wheels 12 and the drive wheels 13 by controlling the input current of each of the multiple drive motors 14.
[0024] Therefore, in the present application, the lawn mower robot 1 adopts a plurality of drive motors 14 with the same rated power, and the drive control system 15 can control the rotational speed of the omnidirectional wheels 12 and the drive wheels 13 by controlling the magnitude of the respective input currents of the plurality of drive motors 14, thereby forcing one or more of the sliding friction between the omnidirectional wheels 12 and the drive wheels 13 and the ground to be converted into rolling friction to avoid slipping, or adjust the rotational speed of the omnidirectional wheels 12 and the drive wheels 13 when they are not slipping with the ground, thereby adjusting the travel speed of the lawn mower robot 1, so as to overcome the resistance between the omnidirectional wheels 12 and the drive wheels 13 of the lawn mower robot 1 and the ground and ensure the travel speed of the lawn mower robot 1. Even in places where the grass is deep and the resistance is relatively large, the lawn mower robot 1 can move normally without slipping, thereby enhancing the mowing ability of the lawn mower robot 1 and avoiding damaging the lawn.
[0025] Referring to Figure 4 , the omnidirectional wheel 12 has at least two degrees of freedom. Compared to a conventional rubber tire with only one degree of freedom, the additional degree of freedom of the omnidirectional wheel 12 is located in the tire tread, allowing it to rotate by contact with the ground. The rotational surface forms a certain angle with the rotational surface of a conventional rubber tire with only one degree of freedom. The omnidirectional wheel 12 can be, but is not limited to, a continuously rotating wheel or a Mecanum wheel.
[0026] In this embodiment, the omnidirectional wheel 12 is a continuously switching wheel. It includes a hub 120 and a plurality of auxiliary wheels 125, which are intermittently mounted on the hub 120. When the omnidirectional wheel 12 moves forward, the hub 120 rotates about the central axis of the wheel 12, driving the auxiliary wheels 125 to rotate around the central axis of the wheel 12. When the omnidirectional wheel 12 turns, not only can the hub 120 rotate about the central axis of the wheel 12, driving the auxiliary wheels 125 to rotate around the central axis of the wheel 12, but the auxiliary wheels 125 can also rotate relative to the hub 120, with the hub 120 serving as the rotation axis. Therefore, the omnidirectional wheel 12 has an additional degree of freedom of rolling around the hub 120 relative to the drive wheel 13.
[0027] In some embodiments, the omnidirectional wheel 12 is a single-row wheel, a coaxially arranged double-row wheel, or a coaxially arranged multiple-row wheel. In this embodiment, the omnidirectional wheel 12 is a double-row wheel. Referring to Figures 4 and 5 , the double-row wheel includes an axle 123 and two wheels 124. The two wheels 124 are connected to the axle 123. Each wheel 124 includes a hub 120 and a plurality of auxiliary wheels 125. The auxiliary wheels 125 of each wheel 124 are interspaced and inserted into the hub 120 of the wheel 124. Furthermore, the projections of the two wheels 124 in a plane perpendicular to the axis of the axle 123 partially overlap. When the double-row wheel rotates until the auxiliary wheels 125 of both wheels 124 touch the ground simultaneously, the specific pressure exerted by the auxiliary wheels 125 on the ground is reduced compared to when a single auxiliary wheel 125 touches the ground, minimizing damage to the lawn. Furthermore, the rotation of the auxiliary wheels 125 helps to remove debris from the gap between the auxiliary wheels 125 and the axle 123, thereby improving operational flexibility. Referring to Figure 5 , the auxiliary wheels 125 on different wheels 124 are staggered to form a complete circle, which can improve the smoothness of movement and prevent unevenness during rotation. In other embodiments, the omnidirectional wheel 12 can be a multi-row wheel, comprising an axle and multiple wheels, each of which is connected to the axle. Each wheel includes a hub and a number of auxiliary wheels, and the auxiliary wheels of each wheel are interspersed on the hub of the wheel. The auxiliary wheels on different wheels are staggered to form a complete circle, which can improve the smoothness of movement and prevent unevenness during rotation. In other embodiments, the auxiliary wheels 125 on different wheels 124 can be at least partially non-staggered. Therefore, the projection of the shape formed by the auxiliary wheels 125 on different wheels 124 into a plane perpendicular to the axis of the axle 123 is a polygon.
[0028] 6 , the driving wheel 13 is a conventional rubber tire with only one degree of freedom, that is, it rotates around the central axis of the driving wheel 13. Similarly, each driving wheel 13 may include one rubber tire or two or more coaxially arranged rubber tires, which are not limited here.
[0029] In some embodiments, referring again to FIG2 , the motor models of the plurality of drive motors 14 are the same, that is, all parameters of the plurality of drive motors 14 are the same.
[0030] Therefore, it is convenient to select and prepare the model of the driving motor 14 , and it is also convenient to install the driving motor 14 on the lawn mowing robot 1 .
[0031] In some embodiments, the drive motor 14 may be, but is not limited to, a hub motor, a conventional motor plus a gear-driven drive motor, or the like.
[0032] In some embodiments, the rated torques of several drive motors 14 are the same, wherein the rated torque refers to the torque output by the drive motor 14 at the rated power. A motor whose rated torque of the drive motor 14 is less than a preset threshold is defined as a low-torque motor. In some embodiments, the preset threshold is 0.3 Nm. In other embodiments, the preset threshold can be appropriately adjusted as needed. Generally speaking, the output torque of the drive motor 14 can also be amplified after gear reduction. For example, in an exemplary embodiment, the torque of the drive motor 14 at the rated output power is 0.24 Nm, and the torque output by the drive motor 14 at the rated output power can reach 2.4 Nm after gear reduction. In this embodiment, four drive motors 14 are used, all of which are hub motors with relatively low rated torques. For example, hub motors with a rated torque of 0.24 Nm have been tested. In various mowing environments, with varying grass growth and lodging conditions, the robot can achieve turning or pivoting in place with sufficient power, avoiding slipping and grass grinding. Furthermore, the use of low-torque motors can significantly reduce the motor cost of the robot mower 1, reduce the overall weight of the robot mower 1, and thus reduce energy consumption. The wear and tear on the lawn caused by the robot mower's heavy weight can also be reduced. It is understood that in other embodiments, the drive motors 14 may be motors with a rated torque greater than or equal to 0.3 Nm, and this is not a limitation here.
[0033] In some embodiments, please refer to Figure 2 again, the main bracket 11 is in the shape of a big belly, which is wide in the middle and narrow at the front and back ends. The direction parallel to the symmetry axis X of the lawn mowing robot 1 is defined as M, wherein the direction indicated by the arrow of the direction M is the front, and the opposite direction of the direction indicated by the arrow of the direction M is the rear. The first end 111 can be located at the front end or the rear end of the main bracket 11. In this embodiment, the first end 111 is located at the front end of the main bracket 11. The lawn mowing robot 1 includes a front axle 16, which is fixed on the first end 111. The extension direction of the front axle 16 is roughly perpendicular to the direction M. There are two omnidirectional wheels 12, which are respectively arranged on the opposite ends of the front axle 16 and are located on the opposite sides of the first end 111. The two omnidirectional wheels 12 are driven by two drive motors 14 respectively.
[0034] In some embodiments, referring to FIG. 4 , the front axle 16 has an arched portion 161 with an axial hole 1611 defined therein. The central axis of the axial hole 1611 is parallel to the direction M. The first end 111 of the main frame 11 has an axle (not shown) corresponding to the axial hole 1611 , and the axle is parallel to the direction M. The front axle 16 is connected to the first end 111 of the main frame 11 via the axial hole 1611 and the axle. When the axial hole 1611 rotates relative to the axle, the front axle 16 can rotate relative to the main frame 11 about the axis, thereby enabling the lawn mower robot 1 to adapt to uneven roads to a certain extent.
[0035] In some embodiments, as shown in Figures 2 and 6 , the second end 112 can be located at the front or rear end of the main frame 11. In this embodiment, the second end 112 is located at the rear end of the main frame 11. The lawn mower robot 1 includes a rear axle 17 secured to the second end 112. Two drive wheels 13 are disposed on opposite ends of the rear axle 17 and on opposite sides of the second end 112. The two drive wheels 13 drive two drive motors 14, respectively.
[0036] In addition, compared with traditional lawn mower robots in which all four wheels are drive wheels, the lawn mower robot 1 of the present application uses omnidirectional wheels 12 as the front wheels and drive wheels 13 as the rear wheels. Since the weight of the omnidirectional wheels 12 is less than that of the drive wheels 13, the overall weight of the lawn mower robot 1 can be reduced. The omnidirectional wheels 12 have greater degrees of freedom, which can reduce wear and tear on the lawn.
[0037] In other embodiments, the two omnidirectional wheels 12 are symmetrical with respect to the symmetry axis X of the main frame 11 and are tilted relative to the symmetry axis X of the main frame 11 to form an "eight" shape.
[0038] When the drive motor 14 provides the same driving force to the omnidirectional wheels 12, compared with the omnidirectional wheels 12 being symmetrical and parallel to the symmetry axis X of the main frame 11, when the omnidirectional wheels 12 are symmetrical and tilted in an eight-shaped shape relative to the symmetry axis X of the main frame 11, the lawn mower robot 1 is easier to turn.
[0039] In some embodiments, the drive control system 15 adjusts the input current of the drive motors 14 and adjusts the rotational speed of the omnidirectional wheel 12 and the drive wheel 13 based on different working scenarios, wherein the different working scenarios include straight driving, turning, turning in place, and climbing.
[0040] In some embodiments, referring to FIG. 1 , the omnidirectional wheels 12 include a left omnidirectional wheel 121 and a right omnidirectional wheel 122. The drive wheels 13 include a left drive wheel 131 and a right drive wheel 132. Four drive motors 14 are provided. The left omnidirectional wheel 121 and the left drive wheel 131, driven by their respective two drive motors 14, generate equal rotational speeds V1 and V3. The right omnidirectional wheel 122 and the right drive wheel 132, driven by their respective two drive motors 14, generate equal rotational speeds V2 and V4. The rotational speed V1 of the left omnidirectional wheel 121 refers to the rotational speed of the left omnidirectional wheel 121 relative to its axle 123. The rotational speed V2 of the right omnidirectional wheel 122 refers to the rotational speed of the right omnidirectional wheel 122 relative to its axle 123. The rotational speed V3 of the left drive wheel 131 refers to the rotational speed of the left drive wheel 131 relative to its central axis. The rotational speed V4 of the right drive wheel 132 refers to the rotational speed of the right drive wheel 132 relative to its central axis. It is understandable that in other embodiments, in order to adapt to different complex terrain environments, the rotational speeds V1 and V3 generated by the left omnidirectional wheel 121 and the left drive wheel 131 being driven by the corresponding two drive motors 14 may not be equal, and the rotational speeds V2 and V4 generated by the right omnidirectional wheel 122 and the right drive wheel 132 being driven by the corresponding two drive motors 14 may not be equal.
[0041] Referring again to Figure 1 , when the robot mower 1 is moving straight ahead normally, the left drive wheel 131, right drive wheel 132, left omnidirectional wheel 121, and right omnidirectional wheel 122 rotate in the same direction. The rotational speed V1 of the left omnidirectional wheel 121, the rotational speed V2 of the right omnidirectional wheel 122, the rotational speed V3 of the left drive wheel 131, and the rotational speed V4 of the right drive wheel 132 are all equal. When the robot mower 1 makes a sharp turn, the instantaneous center of velocity of the robot mower 1 is located outside the body of the robot mower 1. The left drive wheel 131, right drive wheel 132, left omnidirectional wheel 121, and right omnidirectional wheel 122 rotate in the same direction, but the rotational speeds of the two wheels on the inside of the turn are slower than those of the other two wheels on the outside of the turn. Specifically, when the lawn mower robot 1 turns right, the rotational speed V4 of the right drive wheel 132 and the rotational speed V2 of the right omnidirectional wheel 122 located on the inside of the turn are less than the rotational speed V3 of the left drive wheel 131 and the rotational speed V1 of the left omnidirectional wheel 121 located on the outside of the turn; conversely, when the lawn mower robot 1 turns left, the rotational speed V3 of the left drive wheel 131 and the rotational speed V1 of the left omnidirectional wheel 121 located on the inside of the turn are less than the rotational speed V4 of the right drive wheel 132 and the rotational speed V2 of the right omnidirectional wheel 122 located on the outside of the turn.
[0042] In some embodiments, please refer to FIG7 , when the lawn mower robot 1 turns in place, the rotation speed V1 of the left omnidirectional wheel 121, the rotation speed V2 of the right omnidirectional wheel 122, the rotation speed V3 of the left drive wheel 131, and the rotation speed V4 of the right drive wheel 132 are equal, the left omnidirectional wheel 121 and the left drive wheel 131 rotate in the same direction, the right omnidirectional wheel 122 and the right drive wheel 132 rotate in the same direction, and the rotation direction of the left drive wheel 131 is opposite to the rotation direction of the right drive wheel 132. The instantaneous center of velocity A of the lawn mower robot 1 is between the left drive wheel 131 and the right drive wheel 132. The left omnidirectional wheel 121 is located at the midpoint of the line connecting the right drive wheel 132. This is because the speed of the left omnidirectional wheel 121 when the lawn mower robot 1 turns or turns in place is the combined speed of the first speed generated by the drive motor 14 driving the left omnidirectional wheel 121 and the second speed generated by the rolling of the auxiliary wheel 125 of the left omnidirectional wheel 121. Therefore, when the left omnidirectional wheel 121 and the left drive wheel 131 are not slipping and the speeds V1 and V3 generated by the corresponding drive motors 14 are equal, the actual speed of the left omnidirectional wheel 121 will be greater than the actual speed of the left drive wheel 131. The relationship between the speeds of the right omnidirectional wheel 122 and the right drive wheel 132 is similar and will not be further described.
[0043] When the driving control system 15 is actually pacing the left driving wheel 131, the right driving wheel 132, the left omnidirectional wheel 121 and the right omnidirectional wheel 122, the left omnidirectional wheel 121 and the left driving wheel 131 are driven by the corresponding two driving motors 14 to generate the same speeds V1 and V3, and the right omnidirectional wheel 122 and the right driving wheel 132 are driven by the corresponding other two driving motors 14 to generate the same speeds V2 and V4. As for the left omnidirectional wheel 121, the left driving wheel 131 and the right omnidirectional wheel 1 22. The rotation direction of the right drive wheel 132 is determined based on the actual turning radius of the robot mower 1. After the respective speeds of the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122 are determined, the speeds of the left omnidirectional wheel 121 and the right omnidirectional wheel 122 will increase due to the rolling of their auxiliary wheels 125. Ultimately, when the robot mower 1 turns in place, the instantaneous center of velocity A is located at the midpoint of the line connecting the left drive wheel 131 and the right drive wheel 132.
[0044] In some other embodiments, when the lawn mower robot 1 turns in place, the left omnidirectional wheel 121 and the left drive wheel 131 are driven by the corresponding two drive motors 14 to generate equal rotational speeds V1 and V3; the right omnidirectional wheel 122 and the right drive wheel 132 are driven by the corresponding other two drive motors 14 to generate equal rotational speeds V2 and V4; the rotational speeds of the left drive wheel 131 and the right drive wheel 132 are unequal, the left omnidirectional wheel 121 and the left drive wheel 131 rotate in the same direction, the right omnidirectional wheel 122 and the right drive wheel 132 rotate in the same direction, and the left drive wheel 131 rotates in opposite directions to the right drive wheel 132, the instantaneous center of velocity A of the lawn mower robot 1 floats left and right on the line connecting the left drive wheel 131 and the right drive wheel 132. Specifically, when the rotational speed V3 of the left drive wheel 131 is less than the rotational speed V4 of the right drive wheel 132, the instantaneous center A of the speed of the lawn mower robot 1 floats on the side of the line connecting the left drive wheel 131 and the right drive wheel 132 toward the left drive wheel 131; when the rotational speed V4 of the right drive wheel 132 is less than the rotational speed V3 of the left drive wheel 131, the instantaneous center A of the speed of the lawn mower robot 1 floats on the side of the line connecting the left drive wheel 131 and the right drive wheel 132 toward the right drive wheel 132.
[0045] In addition, when the mowing robot 1 climbs a slope, the drive motor 14 needs to provide greater torque to overcome the potential energy of gravity. When the mowing robot 1 moves on flat ground, it may also encounter some situations where the travel resistance is relatively large, resulting in a relatively slow travel speed. Therefore, even if the drive motors 14 have the same output current, the actual speeds obtained by the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122 of the mowing robot 1 will also vary. Therefore, in some embodiments, the drive control system 15 is also used to:
[0046] Detecting the real-time rotational speeds of the left driving wheel 131, the right driving wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122, and comparing them with the current corresponding target rotational speeds of the left driving wheel 131, the right driving wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122;
[0047] Determine the wheel whose real-time rotation speed is less than the corresponding target rotation speed among the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121 and the right omnidirectional wheel 122 as the target wheel, and determine the drive motor 14 driving the target wheel as the target drive motor;
[0048] The input current to the target drive motor is increased so that the real-time rotational speed of the target wheel driven by the target drive motor approaches the target rotational speed.
[0049] It will be understood that the target speed refers to the speed assigned to each of the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122 after the lawn mower robot 1 has determined its travel speed, taking into account the current operating scenario, such as straight-ahead travel, turning, pivoting, or climbing. The drive control system 15 determines the input current to each of the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122 based on their respective target speeds. The real-time speed refers to the actual speed of the drive motor 14 corresponding to each of the left drive wheel 131, the right drive wheel 132, the left omnidirectional wheel 121, and the right omnidirectional wheel 122 when the drive motor 14 begins operating according to the determined input current. The magnitude of the input current added to the target drive motor by the drive control system 15 can be determined based on the difference between the real-time speed of the target wheel and the target speed. When the difference between the real-time rotational speed of the target wheel and the target rotational speed is relatively large, the drive control system 15 controls the increase in the amplitude of the input current of the target drive motor to increase. When the difference between the real-time rotational speed of the target wheel and the target rotational speed is relatively small, the drive control system 15 controls the increase in the amplitude of the input current of the target drive motor to be relatively small.
[0050] In some embodiments, please refer to Figure 8, which is a top view of the lawn mower robot in the second embodiment of the present application when the central axis of the drive wheel is perpendicular to the symmetry axis of the lawn mower robot. The lawn mower robot 1 in the second embodiment is similar in structure to the lawn mower robot 1 in the first embodiment, except that, in the second embodiment, the lawn mower robot 1 includes a steering motor 18, and the steering motor 18 is connected to the drive wheel 13. It can be understood that when the lawn mower robot 1 includes a steering motor 18, the steering motor 18 can be directly fixed to the second end 112 of the main bracket 11. In this case, the rear axle 17 can be omitted. The steering motor 18 can drive the drive wheel 13 to rotate while being tilted relative to the symmetry axis X of the lawn mower robot 1.
[0051] In this embodiment, there is one steering motor 18. The lawn mower robot 1 also includes a transmission mechanism 19. The two ends of the steering motor 18 are connected to the left drive wheel 131 and the right drive wheel 132, respectively, via the transmission mechanism 19. Therefore, rotation of the output shaft of the steering motor 18 can simultaneously drive the left and right drive wheels 131, 132 to rotate, causing the left and right drive wheels 131, 132 to be tilted or parallel relative to the symmetry axis X of the lawn mower robot 1.
[0052] Specifically, in this embodiment, the steering motor 18 includes a first connection end 181 and a second connection end 182. The first connection end 181 and the second connection end 182 are located on opposite sides of the steering motor 18. The transmission mechanism 19 includes a first transmission mechanism 191 connected between the left drive wheel 131 and the first connection end 181 of the steering motor 18, and a second transmission mechanism 192 connected between the right drive wheel 132 and the second connection end 182 of the steering motor 18. Thus, the steering motor 18 drives the left drive wheel 131 to rotate to a predetermined angle relative to the axis of symmetry X via the first transmission mechanism 191, and drives the right drive wheel 132 to rotate to a predetermined angle relative to the axis of symmetry X via the second transmission mechanism 192.
[0053] In some embodiments, referring to FIG9 , the first transmission mechanism 191 includes a first link 1911 and a second link 1912. One end of the first link 1911 is connected to the drive motor 14 for driving the left drive wheel 131, and the other end of the first link 1911 is connected to one end of the second link 1912. The other end of the second link 1912 is connected to the first connection end 181 of the steering motor 18. The second transmission mechanism 192 includes a third link 1921 and a fourth link 1922. One end of the third link 1921 is connected to the drive motor 14 for driving the right drive wheel 132, and the other end of the third link 1921 is connected to one end of the fourth link 1922. The other end of the fourth link 1922 is connected to the second connection end 182 of the steering motor 18.
[0054] Thus, the motion transmission between the steering motor 18 and the left drive wheel 131 is realized by the first transmission mechanism 191 including the first link 1911 and the second link 1912, and the motion transmission between the second transmission mechanism 192 and the right drive wheel 132 is realized by the second transmission mechanism 192 including the third link 1921 and the fourth link 1922.
[0055] In other embodiments, the number of steering motors 18 may be two, that is, the steering motors 18 include a left steering motor and a right steering motor, the left steering motor being connected to the left drive wheel 131, and the right steering motor being connected to the right drive wheel 132. The left steering motor drives the left drive wheel 131 to rotate relative to the axis of symmetry X, and the right steering motor drives the right drive wheel 132 to rotate relative to the axis of symmetry X.
[0056] In some embodiments, please refer to Figure 9, the central axis of the left drive wheel 131 and the central axis of the right drive wheel 132 intersect, the rotation speed V1 of the left omnidirectional wheel 121, the rotation speed V2 of the right omnidirectional wheel 122, the rotation speed V3 of the left drive wheel 131 and the rotation speed V4 of the right drive wheel 132 are equal; the left omnidirectional wheel 121 and the left drive wheel 131 have the same rotation direction, the right omnidirectional wheel 122 and the right drive wheel 132 have the same rotation direction, and when the rotation direction of the left drive wheel 131 is opposite to that of the right drive wheel 132, the instantaneous center A of velocity when the lawn mower robot 1 rotates in place is at the intersection of the central axis of the left drive wheel 131 and the central axis of the right drive wheel 132.
[0057] Therefore, when the left driving wheel 131 is tilted relative to the symmetry axis X and the right driving wheel 132 is tilted relative to the symmetry axis X, the lawn mower robot 1 is easier to turn than when the left driving wheel 131 is parallel to the symmetry axis X and the right driving wheel 132 is parallel to the symmetry axis X.
[0058] It should be noted that those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by this application. The drive control system may include a processor and a memory, wherein the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a readily available programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The memory is a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, or the like.
[0059] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the creative concept of the present application, and these all fall within the scope of protection of the present application.
Claims
1. A lawn mowing robot, characterized in that: The lawn mowing robot includes a main body bracket, omnidirectional wheels, driving wheels, several driving motors and a driving control system; the main body bracket includes a first end and a second end; the first end and the second end are arranged opposite to each other; the omnidirectional wheel is arranged on the first end; the driving wheel is arranged on the second end; the several driving motors are arranged corresponding to the omnidirectional wheels and the driving wheels; each of the driving motors is connected to the corresponding omnidirectional wheel and drives the omnidirectional wheel to rotate or is connected to the corresponding driving wheel and drives the driving wheel to rotate; the driving control system is used to connect to the several driving motors, and control the rotation speed of the omnidirectional wheel and the driving wheel by controlling the size of the input current of each of the several driving motors.
2. The lawn mowing robot according to claim 1, characterized in that: The rated powers of the plurality of drive motors are the same, and / or the motor models of the plurality of drive motors are the same.
3. The lawn mowing robot according to claim 1, characterized in that: The drive control system adjusts the input current of the plurality of drive motors based on different working scenarios and thereby adjusts the rotational speeds of the omnidirectional wheel and the drive wheel. The different working scenarios include at least one of straight driving, turning, turning on the spot and climbing.
4. The lawn mowing robot according to claim 3, characterized in that: The drive control system is used for: Detecting the real-time rotation speeds of the omnidirectional wheel and the driving wheel, and comparing them with the current corresponding target rotation speeds respectively; Determine that the omnidirectional wheel and the driving wheel whose real-time rotation speed is less than the corresponding target rotation speed is a target wheel, and determine that the driving motor driving the target wheel is a target driving motor; An input current is increased to the target drive motor, so that the target drive motor drives the target wheel to increase the real-time rotation speed to approach the target rotation speed.
5. The lawn mowing robot according to any one of claims 1 to 4, characterized in that: The lawn mowing robot comprises a front axle, which is fixed on the first end. The number of the omnidirectional wheels is two, which are respectively arranged on two opposite ends of the front axle.
6. The lawn mowing robot according to claim 5, characterized in that: The front axle has an arched portion with an axial hole arranged on the arched portion. The central axis of the axial hole is parallel to the symmetry axis of the main body bracket. The first end of the main body bracket has an axis corresponding to the axial hole. The front axle is connected to the first end of the main body bracket through the axial hole and the axis.
7. The lawn mowing robot according to claim 5, characterized in that: The lawn mowing robot comprises a rear axle which is fixed on the second end, and there are two driving wheels which are respectively arranged on two opposite ends of the rear axle.
8. The lawn mowing robot according to claim 5, characterized in that: The omnidirectional wheels are arranged in an eight-shaped symmetry relative to the symmetry axis of the main frame.
9. The lawn mowing robot according to claim 7, characterized in that: The omnidirectional wheels include a left omnidirectional wheel and a right omnidirectional wheel, and the drive wheels include a left drive wheel and a right drive wheel; the left omnidirectional wheel and the left drive wheel are driven by the two corresponding drive motors to generate equal rotational speeds, and the right omnidirectional wheel and the right drive wheel are driven by the two corresponding drive motors to generate equal rotational speeds.
10. The lawn mowing robot according to claim 9, characterized in that: When the lawn mower robot turns on the spot, the rotation speeds of the left drive wheel and the right drive wheel are equal, the rotation directions of the left omnidirectional wheel and the left drive wheel are the same, the rotation directions of the right omnidirectional wheel and the right drive wheel are the same, and the rotation direction of the left drive wheel is opposite to that of the right drive wheel, the instantaneous center of speed of the lawn mower robot is at the midpoint of the line connecting the left drive wheel and the right drive wheel.
11. The lawn mowing robot according to claim 9, characterized in that: When the lawn mower robot turns on the spot, the rotation speeds of the left drive wheel and the right drive wheel are not equal, the left omnidirectional wheel and the left drive wheel rotate in the same direction, the right omnidirectional wheel and the right drive wheel rotate in the same direction, and the rotation direction of the left drive wheel is opposite to that of the right drive wheel, the instantaneous center of speed of the lawn mower robot floats left and right on the line connecting the left drive wheel and the right drive wheel.
12. The lawn mowing robot according to any one of claims 1 to 4, characterized in that: The lawn mowing robot comprises a steering motor, which is connected to the driving wheel. The steering motor can drive the driving wheel to rotate so as to be inclined relative to the symmetry axis of the main body bracket.
13. The lawn mowing robot according to claim 12, characterized in that: The omnidirectional wheel comprises a left omnidirectional wheel and a right omnidirectional wheel, the drive wheel comprises a left drive wheel and a right drive wheel, the steering motor comprises a left steering motor and a right steering motor, the left steering motor is connected to the left drive wheel, the right steering motor is connected to the right drive wheel, the central axis of the left drive wheel intersects with the central axis of the right drive wheel, when the rotation speeds of the left omnidirectional wheel, the left drive wheel, the right omnidirectional wheel and the right drive wheel are equal, the rotation directions of the left omnidirectional wheel and the left drive wheel are the same, the rotation directions of the right omnidirectional wheel and the right drive wheel are the same, and the rotation directions of the left drive wheel and the right drive wheel are opposite, the instantaneous center of speed of the lawn mowing robot is at the intersection of the central axis of the left drive wheel and the central axis of the right drive wheel.
14. The lawn mowing robot according to any one of claims 1 to 4, characterized in that: The omnidirectional wheels are single-row wheels, coaxially arranged double-row wheels, or coaxially arranged multiple-row wheels.
15. The lawn mowing robot according to claim 14, characterized in that: The double-row wheels include a wheel axle and two wheels, the two wheels are connected to the wheel axle, each wheel includes a wheel hub and a plurality of auxiliary wheels, the auxiliary wheels of each wheel are arranged on the wheel hub at intervals, and the auxiliary wheels on different wheels are staggered to form a complete circle; or, the multi-row wheels include a wheel axle and a plurality of wheels, the plurality of wheels are connected to the wheel axle, each wheel includes a wheel hub and a plurality of auxiliary wheels, the auxiliary wheels of each wheel are arranged on the wheel hub at intervals, and the auxiliary wheels on different wheels are staggered to form a complete circle.
16. The lawn mowing robot according to claim 13, characterized in that: The lawn mowing robot also includes a transmission mechanism, and the two ends of the steering motor are respectively connected to the left drive wheel and the right drive wheel through the transmission mechanism. The rotation of the output shaft of the steering motor can simultaneously drive the left drive wheel and the right drive wheel to rotate, so that the left drive wheel and the right drive wheel are inclined or parallel to the symmetry axis of the lawn mowing robot.
17. The lawn mowing robot according to claim 16, characterized in that: The steering motor includes a first connection end and a second connection end, wherein the first connection end and the second connection end are respectively located on opposite sides of the steering motor, and the transmission mechanism includes a first transmission mechanism connected between the left driving wheel and the first connection end of the steering motor and a second transmission mechanism connected between the right driving wheel and the second connection end of the steering motor.
18. The lawn mowing robot according to claim 17, characterized in that: The first transmission mechanism includes a first connecting rod and a second connecting rod, one end of the first connecting rod is connected to the driving motor for driving the left driving wheel, the other end of the first connecting rod is connected to one end of the second connecting rod, and the other end of the second connecting rod is connected to the first connecting end of the steering motor; and / or, the second transmission mechanism includes a third connecting rod and a fourth connecting rod, one end of the third connecting rod is connected to the driving motor for driving the right driving wheel, the other end of the third connecting rod is connected to one end of the fourth connecting rod, and the other end of the fourth connecting rod is connected to the second connecting end of the steering motor.
19. The lawn mowing robot according to claim 13, characterized in that: The steering motor includes a left steering motor and a right steering motor, the left steering motor is connected to the left drive wheel, the right steering motor is connected to the right drive wheel, the left steering motor drives the left drive wheel to rotate relative to the symmetry axis of the lawn mower robot, and the right steering motor drives the right drive wheel to rotate relative to the symmetry axis of the lawn mower robot.