Zero position calibration device and zero position calibration method of cleaning robot

Abstract

The present invention discloses a zero-position calibration device for a cleaning robot, comprising: a chassis bracket; a wheel assembly, wherein the wheel assembly comprises a front wheel and two or more rear wheels; a transmission assembly and a drive assembly, wherein the transmission assembly is arranged on the chassis bracket and the wheel assembly, the drive assembly is arranged on the chassis bracket, and the drive assembly is connected to the wheel assembly; a calibration assembly, wherein the calibration assembly comprises an absolute value encoder, a first limiter, a second limiter and a positioning member, the absolute value encoder is connected to the front wheel, the absolute value encoder is arranged on the chassis bracket, the first limiter and the second limiter are respectively and correspondingly arranged on the chassis bracket, and the positioning member is arranged in conjunction with the first limiter and the second limiter.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning robots, and in particular to a zero position calibration device and a zero position calibration method of a cleaning robot. Background Art

[0002] Most of the outdoor cleaning robots in the prior art have a three-wheel structure, with one front wheel responsible for steering and two rear wheels responsible for driving forward, to achieve autonomous movement in conjunction with automatic driving navigation. In actual driving scenarios, the front wheels of outdoor cleaning robots that have just been put into use will mostly have angle deviations caused by assembly, or after being used for a period of time, the front wheels of the cleaning robots will have positioning deviations due to structural wear, which will cause certain route deviations during the driving process and affect the cleaning effect. Summary of the invention

[0003] One object of the present invention is to provide a zero-position calibration device and a zero-position calibration method for a cleaning robot, which ensures that the driving route of the cleaning robot is more accurate and improves the cleaning efficiency by accurately calibrating the front wheel steering zero position.

[0004] Other advantages and features of the present invention will become more apparent from the following detailed description and may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims.

[0005] According to one aspect of the present invention, a zero position calibration device for a cleaning robot of the present invention that can achieve the aforementioned objects and other objects and advantages includes:

[0006] Chassis bracket;

[0007] A wheel assembly, the wheel assembly comprising a front wheel and two or more rear wheels, the front wheel and each of the rear wheels are arranged below the chassis bracket, the front wheel is located in the forward direction of the cleaning robot, and each of the rear wheels is located behind the forward direction of the cleaning robot;

[0008] A transmission assembly and a drive assembly, wherein the transmission assembly is arranged on the chassis bracket and the wheel assembly, the drive assembly is arranged on the chassis bracket, and the drive assembly is connected to the wheel assembly;

[0009] A calibration component, the calibration component includes an absolute value encoder, a first limit member, a second limit member and a positioning member, the absolute value encoder is connected to the front wheel, the absolute value encoder is arranged on the chassis bracket, the first limit member and the second limit member are respectively arranged on the chassis bracket accordingly, and the positioning member is arranged in conjunction with the first limit member and the second limit member.

[0010] According to one embodiment of the present invention, the first limit member is a left limit switch, the second limit member is a right limit switch, the positioning member is a zero point positioning column, the left limit switch and the right limit switch are symmetrically arranged on the left and right sides of the center line of the chassis bracket, and the zero point positioning column is rotated left and right until it contacts the left limit switch and the right limit switch respectively.

[0011] According to one embodiment of the present invention, the wheel assembly also includes a front wheel bracket and the front wheel bracket has a bracket shaft, the front wheel bracket is arranged between the front wheel and the chassis bracket, the front wheel is connected to the chassis bracket through the front wheel bracket, the front wheel bracket extends from the front wheel to the top of the chassis bracket, the front wheel bracket is penetrated by the chassis bracket, the front wheel is arranged on the front wheel bracket, the bracket shaft is located at the center position of the front wheel bracket, and the bracket shaft is located at the top of the front wheel bracket.

[0012] According to one embodiment of the present invention, the drive assembly includes a front wheel steering motor and a rear axle drive motor, the front wheel steering motor and the rear axle drive motor are arranged on the chassis bracket, the front wheel steering motor is connected to the front wheel, and the rear axle drive motor is connected to the two rear wheels.

[0013] According to one embodiment of the present invention, the transmission assembly includes a transmission chain group, a transmission sprocket group and a transmission gear group, the transmission gear group includes a first gear and a second gear, each of the transmission sprockets is respectively arranged on the chassis bracket, each of the transmission sprockets is arranged relative to each of the rear wheels, each of the transmission chains is respectively arranged on each of the transmission sprockets and each of the rear wheels, the first gear and the second gear are in a meshing state, the front wheel steering motor has a motor shaft, the motor shaft is located at the center of the front wheel steering motor, the first gear is arranged at the bottom of the motor shaft, the first gear is driven by the motor shaft, the second gear is arranged on the front wheel bracket, the first gear drives the second gear to rotate, the second gear drives the front wheel bracket and the front wheel to rotate, the rear axle drive motor is arranged between each of the transmission sprockets, the rear axle drive motor drives each of the transmission sprockets, and each of the transmission sprockets drives each of the rear wheels to rotate through each of the transmission chains.

[0014] According to one embodiment of the present invention, the calibration component includes a coupling and two or more tapered roller bearings, each of the tapered roller bearings is arranged at the top of the bracket shaft of the front wheel bracket, two tapered roller bearings are arranged up and down, each of the tapered roller bearings is arranged between the bracket shaft and the chassis bracket, the coupling is arranged on the top of the bracket shaft, and the absolute encoder is arranged on the coupling.

[0015] According to one embodiment of the present invention, the first limiting member is a first limiting hole, the second limiting member is a second limiting hole, the first limiting hole is arranged on the chassis bracket, the second limiting hole is perpendicular to the first limiting hole, the second limiting hole and the first limiting hole are arranged correspondingly, and the positioning member is inserted into or removed from the first limiting hole and the second limiting hole.

[0016] According to an embodiment of the present invention, the first limiting hole is a high-precision hole with a diameter of 6 mm, the second limiting hole is an M6 threaded hole, and the positioning member is a zero-point positioning screw.

[0017] According to another aspect of the present invention, a zero-position calibration method of a cleaning robot is applied to the above-mentioned zero-position calibration device of the cleaning robot, and the zero-position calibration method comprises:

[0018] Step A: Enable the one-button zero point calibration mode through the main control module;

[0019] Step B: the front wheel steering motor first rotates to the right until the zero point positioning column touches the right limit switch;

[0020] Step C: the right limit switch sends a signal to the main control module, the main control module controls the front wheel steering motor to stop moving, and the main control module issues a command to the absolute encoder to record the current angle position as A1;

[0021] Step D: the main control module controls the front wheel steering motor to rotate in the opposite direction to the left until the zero point positioning column touches the left limit switch, and the left limit switch sends a signal to the main control module, and the main control module issues an instruction to the absolute value encoder to record the current angle position as B1;

[0022] Step E: the main control module calculates and processes the position information recorded twice by (B1-A1) / 2 to obtain a calculation result, and the calculation result is the zero point angle position C1 of the zero point positioning column of the front wheel assembly;

[0023] Step G: If the automatic navigation algorithm recognizes that the deviation between the actual motion trajectory and the theoretical planning trajectory is greater than a preset angle, the part calibration procedure is automatically performed.

[0024] According to one embodiment of the present invention, step E includes sub-step E1: step C, step D and step E are repeatedly performed 5 times, the average value of the 5 angle positions is calculated as D1, D1 is the information data of the final zero point angle position, D1 is written into the absolute value code, and zero point calibration is completed.

[0025] The beneficial effect of the present invention is that: through the zero-position calibration device of the two embodiments, the present invention enables the cleaning robot to achieve zero-position calibration of the front wheels before being put into use or after being used for a period of time, thereby ensuring the accuracy of the driving route of the cleaning robot and improving the cleaning efficiency and cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional schematic diagram of a zero-position calibration device for a cleaning robot according to an embodiment of the present invention.

[0027] Figure 2 It is a front cross-sectional view of the zero-position calibration device of the cleaning robot according to the above embodiment of the present invention.

[0028] Figure 3 It is a schematic diagram of the calibration process of the zero-position calibration device of the cleaning robot according to the above embodiment of the present invention.

[0029] Figure 4 The figure is a flowchart of the steps of the zero-position calibration method of the cleaning robot according to the above embodiment of the present invention.

[0030] Figure 5 It is a schematic top view of a zero-position calibration device for a cleaning robot according to another embodiment of the present invention.

[0031] Figure 6 It is a side schematic diagram of the zero position calibration device of the cleaning robot according to the above embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0033] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0034] It is understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number. In addition, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more than two.

[0035] In the description of the present invention, it should be understood that "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0037] like Figures 1 to 4 As shown, a zero-position calibration device and a zero-position calibration method of a cleaning robot according to an embodiment of the present invention are disclosed. The zero-position calibration device and the zero-position calibration method of the cleaning robot can realize the calibration of the front wheels so that the moving route of the cleaning robot will not deviate, thereby saving cleaning time and improving cleaning efficiency.

[0038] In detail, the cleaning robot includes a chassis bracket 10, a wheel assembly 20, a transmission assembly 30, a drive assembly 40 and a calibration assembly 50. The wheel assembly 20, the transmission assembly 30, the drive assembly 40 and the calibration assembly 50 are arranged on the chassis bracket 10. The transmission assembly 30, the drive assembly 40 and the calibration assembly 50 are respectively connected to the wheel assembly 20, so as to realize the transmission function, the driving function and the calibration function of the wheel assembly 20. The chassis bracket 10 realizes the moving action of moving forward or turning through the wheel assembly 20, and the wheel assembly 20 transports the chassis bracket 10 to the specified direction. In addition, the chassis bracket 10 is used to carry the rest of the cleaning robot, which can be but not limited to the cleaning components, trash cans, steering wheels and other body components.

[0039] Further, the wheel assembly 20 includes a front wheel bracket 21, a front wheel 22 and two rear wheels 23, the front wheel 22 is arranged in front of the forward direction of the chassis bracket 10, and the two rear wheels 23 are respectively arranged in the rear of the forward direction of the chassis bracket 10, the front wheel bracket 21 is arranged between the front wheel 22 and the chassis bracket 10, the front wheel 22 is connected to the chassis bracket 10 through the front wheel bracket 21, the front wheel bracket 21 extends from the front wheel 22 to the top of the chassis bracket 10, the front wheel bracket 21 is penetrated by the chassis bracket 10, and the front wheel 22 is arranged on the front wheel bracket 21. Further, the front wheel bracket 21 has a bracket shaft 211, the bracket shaft 211 is located at the center of the front wheel bracket 21, and the bracket shaft 211 is located at the top of the front wheel bracket 21.

[0040] The transmission assembly 30 includes a transmission chain group 31, a transmission sprocket group 32 and a transmission gear group 33, each of the transmission sprockets 32 is respectively arranged on the chassis bracket 10, each of the transmission sprockets 32 is arranged relative to each of the rear wheels 23, each of the transmission chains 31 is respectively arranged on each of the transmission sprockets 32 and each of the rear wheels 23, and each of the transmission chains 31 is provided for each of the transmission sprockets 32 and each of the rear wheels 23 to operate synchronously. It is worth noting that since the number of the rear wheels 23 is two, the number of the transmission sprockets 32 is two, and the number of the transmission chains 31 is two. Furthermore, the transmission gear set 33 includes a first gear 331 and a second gear 332, the first gear 331 and the second gear 332 are in a meshing state, the first gear 331 is arranged on the driving assembly 40, and the second gear is arranged on the front wheel bracket 211, the first gear 331 is driven by the driving assembly 40, the first gear 331 drives the second gear 332 to rotate, and the second gear 332 drives the front wheel bracket 211 and the front wheel 22 to rotate, thereby realizing the angle adjustment of the front wheel 22, that is, realizing the position calibration of the front wheel 22, the second gear 332 drives the steering rotation movement of the front wheel 22 through the front wheel bracket 211, and the forward and backward movement of the front wheel 22 is driven by the rear wheel 23.

[0041] The driving assembly 40 includes a front wheel steering motor 41 and a rear axle driving motor 42. The front wheel steering motor 41 is arranged on the chassis bracket 10. The front wheel steering motor 41 has a motor shaft 411. The motor shaft 411 is located at the center of the front wheel steering motor 41. The motor shaft 411 is provided for the first gear 331. The first gear 331 is arranged at the bottom of the motor shaft 411. The first gear 331 is driven by the motor shaft 411, so that the second gear 331 meshed with the first gear 331 is engaged with the second gear 331. 32 is driven, and then drives the front wheel bracket 21 and the front wheel 22, so as to realize the steering action of the front wheel 22, thereby driving the chassis bracket 10 to steer, and realizing the steering of the cleaning robot, the rear axle drive motor 42 is arranged between the two transmission sprockets 32, and the rear axle drive motor 42 drives the two transmission sprockets 32, and each of the transmission sprockets 32 drives each of the rear wheels 23 to rotate through each of the transmission chains 31, thereby driving the chassis bracket 10 to move forward, and realizing the driving of the cleaning robot.

[0042] The calibration assembly 50 includes an absolute encoder 51, a coupling 52, two tapered roller bearings 53, a zero point positioning column 54, a left limit switch 55 and a right limit switch 56, each of the tapered roller bearings 53 is arranged at the top of the support shaft 211 of the front wheel bracket 21, the two tapered roller bearings 53 are arranged up and down, each of the tapered roller bearings 53 is arranged between the support shaft 211 and the chassis bracket 10, the coupling 52 is arranged on the top of the support shaft 211, the absolute encoder 51 is arranged on the coupling 52, the absolute encoder 51 is arranged at the top of the support shaft 211 of the front wheel bracket 21 through the coupling 52, and the second gear 332 is arranged on the front wheel bracket 21.

[0043] Furthermore, the zero point positioning column 54 is arranged on the second gear 332, the left limit switch 55 and the right limit switch 56 are correspondingly arranged on both sides of the second gear 332, the left limit switch 55 and the right limit switch 56 are symmetrically arranged on the left and right sides of the center line of the chassis bracket 10, and the zero point positioning column 54 can rotate left and right until it contacts the left limit switch 55 and the right limit switch 56 respectively.

[0044] In actual application scenarios, when driving the chassis bracket 10 forward, the rear axle drive motor 42 first drives the two transmission sprockets 32, and each transmission sprocket 32 ​​drives each rear wheel 23 through each transmission chain 31. When driving the chassis bracket 10 to turn, the front wheel steering motor 41 drives the front wheel 22 to rotate through the first gear 331 and the second gear 332, thereby controlling the rotation direction of the chassis bracket 10.

[0045] In detail, when the front wheel 22 is turning, the front wheel steering motor 41 starts to operate after receiving the command, and the first gear 331 is arranged on the motor shaft 411 of the front wheel steering motor 41. When the front wheel steering motor 41 rotates, it drives the first gear 331 to rotate, and the first gear 331 is meshed with the second gear 332. Preferably, the transmission ratio of the first gear 331 to the second gear 332 is 1:5, and the second gear 332 and the front wheel bracket 21 can be but not limited to being connected by a screw. The front wheel 22 and the front wheel bracket 21 can be fixed by axial screws, but are not limited to being fixed by the second gear 332. When the second gear 332 rotates, it drives the front wheel bracket 21 and the front wheel 22 to rotate. The top of the bracket shaft 211 of the front wheel bracket 21 supports the chassis bracket 10 through the two tapered roller bearings 53. The top of the bracket shaft 211 of the front wheel bracket 21 is connected to the absolute encoder 51 through the coupling 52. The absolute encoder 51 reads the angle information of the rotation of the front wheel 22 in real time.

[0046] Before the automatic driving control angle, the zero position information of the front wheel 22 is first input into the absolute encoder 51. At this time, the direction of the front wheel 22 is located in the positive direction of the cleaning robot. When the front wheel 22 of the cleaning robot is assembled for the first time, preferably, the front wheel 22 is fixed to the chassis bracket 10 through bearing supports, and the angle direction does not need to be fixed. When the front wheel steering motor 41 rotates, the front wheel steering motor 41 drives the second gear 332, the zero point positioning column 54 and the front wheel 22 to rotate relative to the chassis bracket 10, and the chassis bracket 10 and the left limit switch 55 and the right limit switch 56 are in a relatively stationary state. In detail, as Figure 4 As shown, the step of calibrating the zero position of the front wheel includes:

[0047] Step A: Enable the one-button zero point calibration mode through the main control module;

[0048] Step B: the front wheel steering motor first rotates to the right until the zero point positioning column touches the right limit switch;

[0049] Step C: The right limit switch sends a signal to the main control module, and the main control module controls the front wheel steering motor to stop moving. The main control module issues a command to the absolute encoder to record the current angle position as A1. Figure 3 As shown;

[0050] Step D: the main control module controls the front wheel steering motor to rotate in the opposite direction to the left until the zero point positioning column touches the left limit switch, and the left limit switch sends a signal to the main control module, and the main control module issues an instruction to the absolute value encoder to record the current angle position as B1;

[0051] Step E: the main control module calculates and processes the position information recorded twice by (B1-A1) / 2 to obtain a calculation result, and the calculation result is the zero point angle position C1 of the zero point positioning column of the front wheel assembly;

[0052] Step F: Repeat the process 5 times, calculate the average value of the 5 angle positions as D1, D1 is the information data of the final zero point angle position, write D1 into the absolute value code, and complete the zero point calibration;

[0053] Step G: In subsequent use, if the automatic navigation algorithm recognizes that the deviation between the actual motion trajectory and the theoretical planned trajectory is greater than 2°, the parts calibration procedure is automatically performed. That is, the above calibration method is not only applicable during the initial assembly and production of the cleaning robot, but also after being put into actual use for a period of time, when the automatic navigation algorithm finds that there is a deviation in the actual running route angle of the cleaning robot, automatic calibration can also be achieved.

[0054] Another embodiment of the present invention is a zero-position calibration device and a zero-position calibration method for a cleaning robot. For the sake of simplicity and ease of understanding, only the differences from the above-mentioned embodiments are described. Another zero-point calibration method of the present invention, in detail, the cleaning robot includes a chassis bracket 10, a wheel assembly 20, a transmission assembly 30, a drive assembly 40 and a calibration assembly 50A, the calibration assembly 50A includes a first limiting hole 55A, a second limiting hole 56A and a positioning member 54A, the first limiting hole 55A is provided on the chassis bracket 10, preferably, the first limiting hole 55A is a high-precision hole with a diameter of 6 mm, the second limiting hole 56A is provided on the second gear 332, it is worth noting that the second limiting hole 56A is perpendicular to the first limiting hole 55A, and the second limiting hole 56A and the first limiting hole 55A are provided correspondingly. Furthermore, the positioning member 54A can lock the first limiting hole 55A on the chassis bracket 10 with the second limiting hole 56A of the second gear 332, so that the position of the front wheel 22 is fixed, and the position information is read by the absolute encoder 51, and the current position is set as the zero position. In the subsequent calibration process, the zero position is used as a reference mark. In addition, after setting the zero position, the positioning member 54A is removed so that the front wheel 22 can rotate. This embodiment is used for calibration before the cleaning robot is put into use.

[0055] Preferably, the second limiting hole 56A is an M6 threaded hole.

[0056] Preferably, the positioning member 54A is a zero-point positioning screw, and the zero-point positioning screw can be assembled with the high-precision hole with a diameter of 6 mm and the M6 ​​threaded hole.

[0057] The zero-position calibration device and the zero-position calibration method of the cleaning robot of the present invention can control the rotation angle of the front-wheel steering motor 41 and read the positions of two left-right symmetrical limit switches. A relatively accurate zero-point position can be obtained through multiple calculations. In actual use, the zero-point position can be automatically calibrated in conjunction with a navigation program, so that the travel route is more accurate and the cleaning efficiency is improved.

Claims

1. A zero position calibration device for a cleaning robot, characterized in that: include: Chassis bracket; A wheel assembly, wherein the wheel assembly comprises a front wheel and two rear wheels, the front wheel and each of the rear wheels are arranged below the chassis bracket, the front wheel is located in the forward direction of the cleaning robot, and each of the rear wheels is located behind the forward direction of the cleaning robot; the wheel assembly also comprises a front wheel bracket and the front wheel bracket has a bracket shaft, the front wheel bracket is arranged between the front wheel and the chassis bracket, the front wheel is connected to the chassis bracket through the front wheel bracket, the front wheel bracket extends from the front wheel to the top of the chassis bracket, the front wheel bracket is penetrated by the chassis bracket, the front wheel is arranged on the front wheel bracket, the bracket shaft is located at the center position of the front wheel bracket, and the bracket shaft is located at the top of the front wheel bracket; A transmission assembly and a drive assembly, wherein the transmission assembly is arranged on the chassis bracket and the wheel assembly, the drive assembly is arranged on the chassis bracket, and the drive assembly is connected to the wheel assembly; the drive assembly comprises a front wheel steering motor and a rear axle drive motor, the front wheel steering motor and the rear axle drive motor are arranged on the chassis bracket, the front wheel steering motor is connected to the front wheel, and the rear axle drive motor is connected to the two rear wheels; A calibration component, the calibration component comprising an absolute value encoder, a first limiter, a second limiter and a positioning member, the absolute value encoder being connected to the front wheel, the absolute value encoder being arranged on the chassis bracket, the first limiter and the second limiter being respectively arranged on the chassis bracket correspondingly, and the positioning member being arranged in conjunction with the first limiter and the second limiter; When the cleaning robot is assembled and produced for the first time and is calibrated after being put into actual use for a period of time, the first limit member includes a left limit switch, the second limit member includes a right limit switch, the positioning member includes a zero point positioning column, the left limit switch and the right limit switch are symmetrically arranged on the left and right sides of the center line of the chassis bracket, and the zero point positioning column is rotated left and right until it contacts the left limit switch and the right limit switch respectively; When the cleaning robot is calibrated before being put into use, the first limiting member includes a first limiting hole, the second limiting member includes a second limiting hole, the positioning member includes a zero-point positioning screw, the first limiting hole is provided on the chassis bracket, the second limiting hole is perpendicular to the first limiting hole, the second limiting hole and the first limiting hole are provided correspondingly, and the zero-point positioning screw is inserted into or removed from the first limiting hole and the second limiting hole; By using the above two zero-position calibration devices, the cleaning robot can achieve zero-position calibration of the front wheels before being put into use or after being used for a period of time, thereby ensuring the accuracy of the driving route of the cleaning robot and improving the cleaning efficiency and cleaning effect.

2. The zero position calibration device according to claim 1, characterized in that: The transmission assembly includes a transmission chain group, a transmission sprocket group and a transmission gear group, the transmission gear group includes a first gear and a second gear, each of the transmission sprockets is respectively arranged on the chassis bracket, each of the transmission sprockets is arranged relative to each of the rear wheels, each of the transmission chains is respectively arranged on each of the transmission sprockets and each of the rear wheels, the first gear and the second gear are in a meshing state, the front wheel steering motor has a motor shaft, the motor shaft is located at the center of the front wheel steering motor, the first gear is arranged at the bottom of the motor shaft, the first gear is driven by the motor shaft, the second gear is arranged on the front wheel bracket, the first gear drives the second gear to rotate, the second gear drives the front wheel bracket and the front wheel to rotate, the rear axle drive motor is arranged between each of the transmission sprockets, the rear axle drive motor drives each of the transmission sprockets, and each of the transmission sprockets drives each of the rear wheels to rotate through each of the transmission chains.

3. The zero position calibration device according to claim 2, characterized in that: The calibration assembly includes a coupling and two tapered roller bearings, each of which is arranged at the top of the bracket shaft of the front wheel bracket, the two tapered roller bearings are arranged up and down, each of which is arranged between the bracket shaft and the chassis bracket, the coupling is arranged on the top of the bracket shaft, and the absolute encoder is arranged on the coupling.

4. The zero calibration device according to claim 1, characterized in that: The first limiting hole is a high-precision hole with a diameter of 6 mm, the second limiting hole is an M6 threaded hole, and the positioning member is a zero-point positioning screw.

5. A zero position calibration method for a cleaning robot, characterized in that: In the zero-position calibration device of the cleaning robot according to any one of claims 1 to 4, the zero-position calibration method comprises: Step A: Enable the one-button zero point calibration mode through the main control module; Step B: the front wheel steering motor first rotates to the right until the zero point positioning column touches the right limit switch; Step C: the right limit switch sends a signal to the main control module, the main control module controls the front wheel steering motor to stop moving, and the main control module issues a command to the absolute encoder to record the current angle position as A1; Step D: the main control module controls the front wheel steering motor to rotate in the opposite direction to the left until the zero point positioning column touches the left limit switch, and the left limit switch sends a signal to the main control module, and the main control module issues an instruction to the absolute value encoder to record the current angle position as B1; Step E: the main control module calculates and processes the position information recorded twice by (B1-A1) / 2 to obtain a calculation result, and the calculation result is the zero point angle position C1 of the zero point positioning column of the front wheel assembly; Step G: If the automatic navigation algorithm recognizes that the deviation between the actual motion trajectory and the theoretical planning trajectory is greater than a preset angle, the part calibration procedure is automatically performed.

6. The zero calibration method according to claim 5, characterized in that: The step E includes sub-step E1: repeating the step C, the step D and the step E for 5 times, calculating the average value of the 5 angle positions as D1, D1 is the information data of the final zero point angle position, writing D1 into the absolute value code, and completing the zero point calibration.

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