Mower and electric tool

Abstract

The invention discloses a mowing machine and an electric tool, and the mowing machine comprises a cutting assembly which comprises at least one cutting blade and a cutting motor which drives the cutting blade to execute a cutting action; the power supply device is at least used for supplying power to the cutting motor; and the controller is configured to estimate the rotational inertia of the cutting motor and control the operation of the cutting motor according to the rotational inertia. According to the technical scheme, fault detection of the cutting blade can be achieved through the rotational inertia of the cutting motor, and the reliability of fault detection of the cutting blade is improved.

Description

Technical Field

[0001] The present application relates to the technical field of fault detection of electric tools, and in particular to a lawn mower and an electric tool. Background Art

[0002] Power tools are widely used in the tool field due to their high practicality. Some power tools usually need to be equipped with rotating components to achieve corresponding functions, such as the cutting component in a lawn mower, the fan of the motor, etc. If the cutting component or the motor fan fails, it will seriously affect the functional effect of the power tool.

[0003] This section provides background information related to the present application which is not necessarily prior art. Summary of the invention

[0004] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide a lawn mower and an electric tool to achieve high-reliability fault detection of a rotating assembly of an electric tool.

[0005] According to one aspect of the present application, there is provided a lawn mower, comprising:

[0006] A cutting assembly, comprising at least one cutting blade and a cutting motor for driving the cutting blade to perform a cutting action;

[0007] A power supply device, at least used to supply power to the cutting motor;

[0008] The controller is configured to estimate the moment of inertia of the cutting motor and control the operation of the cutting motor according to the moment of inertia.

[0009] Optionally, the controller controls the operation of the cutting motor by vector control to realize the function of the lawn mower.

[0010] Optionally, the controller is configured to estimate the rotational inertia of the cutting motor by a model reference adaptive method.

[0011] Optionally, the controller is configured to estimate the moment of inertia of the cutting motor by a recursive least squares identification method.

[0012] Optionally, the controller is configured to determine whether the cutting blade is faulty based on the rotational inertia, and control the cutting motor to stop running when it is determined that the cutting blade is faulty.

[0013] Optionally, the controller is configured to determine that the cutting blade is faulty when the moment of inertia satisfies a preset fault condition.

[0014] According to another aspect of the present application, there is provided an electric tool, comprising:

[0015] a drive motor including an output shaft;

[0016] A rotating device, disposed on the output shaft and driven to rotate by the output shaft;

[0017] The controller is configured to estimate the rotational inertia of the drive motor and obtain the state change of the rotating device according to the change of the rotational inertia.

[0018] Optionally, the controller controls the operation of the drive motor by vector control to realize the function of the electric tool.

[0019] Optionally, the controller is configured to estimate the rotational inertia of the drive motor by a model reference adaptive method.

[0020] Optionally, the controller is configured to estimate the rotational inertia of the drive motor by a recursive least squares identification method.

[0021] Optionally, the controller is configured to determine whether the rotating device is faulty based on the rotational inertia, and control the drive motor to stop running when it is determined that the rotating device is faulty.

[0022] Optionally, the controller is configured to determine that the rotating device is faulty when the moment of inertia satisfies a preset fault condition.

[0023] Optionally, the rotating device comprises a fan or a cutting blade.

[0024] According to another aspect of the present application, there is provided a lawn mower, comprising:

[0025] A power supply device, at least used to supply power to the cutting motor;

[0026] A cutting assembly, comprising a cutting disc, a plurality of cutting blades arranged on the cutting disc, and a cutting motor driving the cutting blades to perform cutting actions;

[0027] The controller is configured to estimate the moment of inertia of the cutting motor by a Kalman prediction unit and control the operation of the cutting motor based on the moment of inertia.

[0028] The lawn mower provided in the embodiment of the present application estimates the rotational inertia of the cutting motor in real time when the cutting motor drives the cutting blade to perform a cutting action, so as to detect whether the cutting blade is missing or damaged based on the rotational inertia of the cutting motor. Thus, when it is determined that the cutting blade is missing or damaged, the cutting motor can be promptly controlled to stop running, and the cutting blade fault detection can be realized through the rotational inertia of the cutting motor, thereby improving the reliability of the cutting blade fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural schematic diagram of a lawn mower provided in an embodiment of the present application;

[0030] Figure 2 It is a structural schematic diagram of a cutting assembly provided in an embodiment of the present application;

[0031] Figure 3 is a structural schematic diagram of another lawn mower provided in an embodiment of the present application;

[0032] Figure 4 It is an electric control principle diagram of a driving system of a cutting motor provided in an embodiment of the present application;

[0033] Figure 5 is an electric control principle diagram of another cutting motor drive system provided in an embodiment of the present application;

[0034] Figure 6 This is another electrical control principle diagram of a driving system of a cutting motor provided in an embodiment of the present application;

[0035] Figure 7 is a structural schematic diagram of an electric tool provided in an embodiment of the present application;

[0036] Figure 8 is a schematic structural diagram of another electric tool provided in an embodiment of the present application;

[0037] Fig. 9 is a schematic structural diagram of a drive system of a drive motor provided in an embodiment of the present application;

[0038] Fig.10 is an electronic control principle diagram of another drive motor drive system provided in an embodiment of the present application;

[0039] Fig.11 It is an electric control principle diagram of another drive system of a drive motor provided in an embodiment of the present application;

[0040] Fig.12 It is a model curve diagram for estimating the moment of inertia using the least squares method provided in an embodiment of the present application;

[0041] Fig.13It is a model curve diagram for estimating the moment of inertia using the model reference adaptive method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0043] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0044] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0045] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0046] In the present application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0047] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0048] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that the directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0049] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" are interchangeable. When a unit "controller", "processor", "central processing unit", "CPU", or "MCU" is used to perform a specific function, unless otherwise specified, these functions can be performed by a single unit or multiple units.

[0050] In the present application, the terms “device”, “module” or “unit” may be implemented in the form of hardware or software to achieve specific functions.

[0051] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0052] Figure 1 A structural schematic diagram of a lawn mower provided in an embodiment of the present application, specifically a hand-push lawn mower. Figure 3 It is a structural schematic diagram of another lawn mower provided in an embodiment of the present application, specifically, an intelligent lawn mower. Figure 2 is a schematic diagram of the structure of a cutting assembly provided in an embodiment of the present application, Figure 4 1 is an electric control schematic diagram of a driving system of a cutting motor provided in an embodiment of the present application. Figure 1 As shown, the lawn mower 100 includes: a walking assembly 110, a cutting assembly 120, and a power supply device 170. The walking assembly 110 includes a walking wheel 111 and a walking motor (not shown in the figure) for driving the walking wheel to walk. The cutting assembly 120 includes a cutting disc (not shown in the figure), at least one cutting blade 122 arranged on the cutting disc, and a cutting motor M1 for driving the cutting blade 122 to perform a cutting action. The power supply device 170 is used to at least supply power to the walking motor and the cutting motor. In some embodiments, the power supply device 170 includes a battery pack. See Figure 3 As shown, the lawn mower 100a includes: a traveling assembly 110a having traveling wheels 111a, a cutting assembly, and a power supply device 170a. Figure 4 As shown, the lawn mower further includes a controller 130 configured to estimate the rotational inertia of the cutting motor M1 and control the operation of the cutting motor M1 according to the rotational inertia.

[0053] Specifically, the travel motor can drive the travel wheel 111 to rotate, so that the lawn mower 100 can move. The cutting disc is connected to the output shaft of the cutting motor M1, so that the cutting disc can rotate under the drive of the cutting motor M1, and the cutting blade 122 is fixedly arranged on the cutting disc, so that the multiple cutting blades 122 on the cutting disc can perform cutting actions. The cutting disc is a circular thin sheet. In some embodiments, a plurality of cutting blades, such as 3, 4 or 5, can be fixedly arranged on a cutting disc, and the embodiment of the present application does not specifically limit this. It can be understood that each cutting blade 122 is evenly distributed on the cutting disc. For example, if the number of cutting blades 122 is an odd number, then along the circle with the same distance from the center of the cutting disc, the spacing between each cutting blade 122 is the same distance, so that each cutting blade 122 is evenly distributed on the cutting disc. If the number of cutting blades 122 is an even number, the cutting blades 122 are centrally symmetrically distributed around the center of the cutting disc to achieve uniform distribution of each cutting blade 122 on the cutting disc.

[0054] It is understandable that, since the cutting blades 122 are evenly distributed on the cutting disc, the cutting disc can rotate smoothly under the drive of the cutting motor M1 during the mowing process of the lawn mower 100, thereby achieving a better mowing effect. However, if one or more cutting blades 122 on the cutting disc fail, such as being missing or damaged, the distribution balance of the cutting blades on the cutting disc will be destroyed, including the destruction of the evenly distributed positions or the destruction of the evenly distributed masses. At this time, when the cutting disc rotates, the unbalanced rotation will cause the lawn mower 100 to generate greater vibrations, thereby affecting the mowing effect.

[0055] The cutting motor M1 can be a motor, specifically a three-phase brushless motor including a rotor with a permanent magnet and three-phase stator windings U, V, and W that are electronically commutated. In some embodiments, the three-phase stator windings U, V, and W are star-connected. In other embodiments, the three-phase stator windings U, V, and W are angle-connected. However, it must be understood that other types of brushless motors are also within the scope of the present disclosure. The moment of inertia of the cutting motor M1 can be understood as the moment of inertia of the motor. When one or more cutting blades 122 on the cutting disc fail, the cutting disc begins to rotate unbalancedly, and its moment of inertia changes, such as a large shake, so that the moment of inertia of the cutting motor M1 also shakes greatly. Based on this, during the operation of the lawn mower 100, the mechanical data of the cutting motor M1 can be obtained in real time through the controller 130, so as to estimate the moment of inertia of the cutting motor M1 through the mechanical data. Furthermore, the controller 130 can determine whether the cutting blade fails based on the moment of inertia, and can control the operation of the cutting motor based on the change in the moment of inertia.

[0056] For example, when the moment of inertia of the cutting motor M1 is abnormal, the controller 130 can determine that the cutting blade 122 is faulty, that is, the cutting blade 122 is missing or damaged, and the cutting motor M1 can be controlled to stop running, so that the cutting blade 122 stops cutting. When the moment of inertia of the cutting motor M1 is not abnormal, it can be determined that the cutting blade 122 is not faulty, and the controller 130 can continue to control the cutting motor M1 to run, so that the cutting blade 122 performs mowing.

[0057] Among them, when the cutting blade 122 is not faulty, the estimated moment of inertia is within a certain numerical range. When the moment of inertia is not within the numerical range, it can be determined that the moment of inertia at this time meets the preset fault condition, and then it can be determined that the cutting blade 122 is faulty.

[0058] The lawn mower provided in the embodiment of the present application estimates the rotational inertia of the cutting motor in real time when the cutting motor drives the cutting blade to perform a cutting action, so as to detect whether the cutting blade is missing or damaged based on the rotational inertia of the cutting motor. Thus, when it is determined that the cutting blade is missing or damaged, the cutting motor can be promptly controlled to stop running, and the cutting blade fault detection can be realized through the rotational inertia of the cutting motor, thereby improving the reliability of the cutting blade fault detection.

[0059] Exemplary, reference Figure 4 , the driving system of the cutting motor may include a controller 130, a power supply device 140, a driving circuit 150 for driving the cutting motor M1, and a parameter detection module 160. The driving circuit 150 includes a plurality of electronic switches (Q1, Q2, Q3, Q4, Q5, Q6) electrically connected between the power supply device 140 and the cutting motor M1, and the control end of each electronic switch is electrically connected to the controller 130. The power supply device 140 provides a power signal to the controller 130 and the driving circuit 150 to realize the power supply function. The driving circuit 150 can output a driving signal to the cutting motor M1 according to the power signal and the PWM signal provided by the controller 130 to drive the cutting motor M1 to operate. The parameter detection module 160 is used to obtain the operating data (including operating current, operating voltage, torque or speed, etc.) of driving the cutting motor M1, and transmit the obtained operating data to the controller 130, so that the controller outputs a PWM signal to the driving circuit according to the actual operating data of the motor and the target operating data of the user.

[0060] Optionally, the controller 130 may control the operation of the cutting motor M1 by vector control to realize the functions of the lawn mower 100 .

[0061] Specifically, Figure 5 is a schematic diagram of the structure of another driving system of a cutting motor provided in an embodiment of the present application, such as Figure 5 As shown, the controller 130 may be integrated with a vector control system, which may include at least a current loop circuit, a speed loop circuit, and of course a position loop circuit. The above three closed-loop control circuits are the basic circuits constituting the FOC control circuit, and the FOC control circuit is not introduced in detail in this embodiment. In short, the current loop circuit includes two loops, the quadrature axis (i.e., the q axis) and the direct axis (d axis), and each loop has two input parameters, one of which is a preset current parameter iq * and id *The speed loop circuit can affect the input parameters of the current loop circuit. In other words, the speed loop circuit adds a PI loop (i.e., the speed PI controller 131) in front of the current loop circuit to obtain an input parameter in the current loop circuit, i.e., iq, according to the preset speed parameter and the actual speed parameter of the motor. * and id * Therefore, the current loop circuit and the speed loop circuit can form a speed-current dual closed-loop control. In fact, if Figure 5 In the embodiment, the controller 130 further includes a signal processing module 132, in which a speed and position estimation module 1321, a Clark transformation module 1322 and a Park transformation module 1323 are integrated. The position estimation module 1321 can estimate or directly detect the speed or rotor position of the cutting motor M1, and a sampling resistor (not shown) can directly collect the phase current of the cutting motor M1. The collected phase current is successively Clark transformed and Park transformed by the Clark transformation module 1322 and the Park transformation module 1323 to obtain current parameters iq and id. The q-axis PI controller 133 calculates the current parameters iq and iq according to the current parameters iq and iq * Output q-axis voltage uq * , d-axis PI controller 134 according to id and id * Output d-axis voltage ud * , Park inverse transformation module 135 according to q axis voltage uq * and d-axis voltage ud * Output intermediate control quantity uα * and uβ * , so that the SVPWM module 136 can be based on the intermediate control amount uα * and uβ * Output the corresponding PWM signal.

[0062] Based on the above embodiment, the controller 130 may be configured with a moment of inertia estimation module to estimate the moment of inertia of the cutting motor M1 according to the mechanical data of the cutting motor M1. The present application embodiment does not specifically limit the method for estimating the moment of inertia, and exemplary methods may include recursive least squares identification method, model reference adaptive method, extended Kalman filter method, etc.

[0063] Optional, reference Figure 5 , the controller 130 is configured to estimate the moment of inertia of the cutting motor by a recursive least squares identification method.

[0064] Exemplarily, the controller 130 may include a first moment of inertia estimation module 137 , which can estimate the moment of inertia of the cutting motor by a recursive least squares identification method.

[0065] Specifically, when estimating the moment of inertia, the first moment of inertia estimation module 137 may first obtain a recursive formula of the least square method: in, y is the output, φ is the input, θ is a constant, K matrix is ​​the gain matrix, I is the unit matrix, λ is the forgetting factor, and the value range of λ is [0.95,1], which can reduce the influence of old data during the iteration process.

[0066] Then, the mechanical motion equation for driving the cutting motor M1 (motor) can be obtained: Wherein, J is the moment of inertia of the motor load (cutting disc and cutting blade 122), B m is the wind load friction coefficient of the motor, T e is the motor output torque, T L is the load torque, ω m is the actual speed of the motor. During the simulation, the wind load friction coefficient B can be set m is 0, the mechanical motion equation can be simplified to Denoted as formula (1). Discretizing formula (1) yields formula (2): Ignore the load torque T L The change of , we can get formula (3): We can further obtain the discretization equation at time (k-2): Denoted as formula (4), subtracting formula (3) from formula (4) yields: Thus, we can determine: y(k) = -2ω m (k-1)+ω m (k-2)+ω m (k) The actual motor speed ω m , Motor output torque T e , the corresponding moment of inertia J can be determined to estimate the moment of inertia.

[0067] Optionally, the controller 130 is configured to estimate the moment of inertia of the cutting motor by a model reference adaptive method. Figure 6 is a structural schematic diagram of another driving system of a cutting motor provided in an embodiment of the present application, such as Figure 6 As shown, the controller 130 may include a second moment of inertia estimation module 138 for estimating the moment of inertia of the cutting motor M1 by a model reference adaptive method.

[0068] Specifically, the second moment of inertia estimation module 138 may estimate the moment of inertia according to the mechanical motion equation of the motor: The discretization equation for determining the k-th moment is: The discretization equation at time k-1 is: According to the above two discretization equations, the reference model is determined as: m (k)=2*ω m (k-1)-ω m (k-2)+b*ΔT e (k-1), the adaptive model is Among them, ω m (k) is the actual speed of the motor, is the estimated value of the motor speed, (parameters to be identified), ΔT e (k-1) = T e (k-1)-T e (k-2). Therefore, the deviation between the reference model and the adaptive model is According to the discrete time iterative parameter identification mechanism proposed by Landau, an adaptive algorithm can be designed: In this way, according to the output torque T of the motor at each moment e and speed ω m , the moment of inertia b can be determined and the estimation of the moment of inertia can be realized.

[0069] Based on the same inventive concept, the embodiment of the present application further provides an electric tool, Figure 7 is a schematic diagram of the structure of an electric tool provided in an embodiment of the present application, Figure 8 is a schematic diagram of the structure of another electric tool provided in an embodiment of the present application, Fig. 9 is a schematic diagram of a drive system of a drive motor provided in an embodiment of the present application, and is combined with reference to Figure 7 , Figure 8 and Fig. 9 The electric tool 200 includes a driving motor M2, including an output shaft 211; a rotating device 220, which is arranged on the output shaft 211 and driven to rotate by the output shaft 211; and a controller 230, which is configured to estimate the moment of inertia of the driving motor M2, and obtain the state change of the rotating device 220 according to the change of the moment of inertia.

[0070] Specifically, the electric tool 200 may be a screwdriver, electric drill, wrench, angle grinder, or other electric tool that requires speed regulation, a sander, or other electric tool that may be used to grind a workpiece, a reciprocating saw, a circular saw, a jigsaw, or the like that may be used to cut a workpiece, or an electric hammer, or other electric tool that may be used for impact. These tools may also be garden tools, such as pruning machines, chain saws, and vehicle-type lawn mowers; in addition, these tools may also be used for other purposes, such as blenders. As long as these electric tools can adopt the substantive content of the technical solutions disclosed below, they can fall within the scope of protection of this application. The embodiment of this application only uses the electric tool 200 as an electric drill as an example for illustrative description.

[0071] like Figure 7 As shown, the electric tool 200 includes a housing 270, a motor 230, and a power supply device 240; the drive motor M2 is disposed in the housing 270. The housing 270 can form a storage space for accommodating the drive motor M2, the transmission mechanism and other electronic components such as a circuit board, and is the main part of the electric tool 200. The housing 270 can also be formed with a grip 271 for the user to hold. The drive motor M2 can convert electrical energy into power transmitted to the functional part 280, and the functional part 280 can be installed at the front end of the housing 270.

[0072] The rotating device 220 can be a motor fan, which is driven to rotate by the drive motor M2 and is used to dissipate heat for the drive motor M2. Therefore, the rotating device 220 can also be regarded as a load of the drive motor M2. Among them, the drive motor M2 can be a three-phase brushless motor, including a rotor with permanent magnets and three-phase stator windings U, V, and W that are electronically commutated. In some embodiments, the three-phase stator windings U, V, and W are star-connected, and in other embodiments, the three-phase stator windings U, V, and W are angle-connected. However, it must be understood that other types of brushless motors are also within the scope of the present disclosure.

[0073] It is understandable that when the rotating device 220 is a motor fan, the fan blades form a circle and are evenly distributed, that is, the center angles between adjacent blades are the same. During the operation of the drive motor M2, the motor fan can be driven to rotate smoothly to achieve a good heat dissipation function. However, if one or more blades on the motor fan fail, such as being missing or damaged, the balance of each blade will be destroyed, including the destruction of the evenly distributed position or the destruction of the evenly distributed mass. At this time, when the motor fan rotates, its moment of inertia changes due to the unbalanced rotation, which will affect the heat dissipation effect and indirectly affect the moment of inertia of the drive motor M2.

[0074] Based on this, the mechanical data of the drive motor M2 can be acquired in real time by the controller 230 during the operation of the drive motor M2, so as to estimate the moment of inertia of the drive motor M2 through the mechanical data. Furthermore, the controller 230 can determine whether the rotating device 220 is faulty according to the moment of inertia, and can control the operation of the drive motor M2 according to the change of the moment of inertia.

[0075] For example, when the rotational inertia of the drive motor M2 is abnormal, the controller 230 can determine that the rotating device 220 is faulty, that is, the fan blades of the motor fan are missing or damaged, and the drive motor M2 can be controlled to stop running, so that the rotating device 220 stops rotating to dissipate heat. When the rotational inertia of the drive motor M2 is not abnormal, it can be determined that the rotating device 220 is not faulty, and the controller 230 can continue to control the drive motor M2 to run, so that the rotating device 220 continues to rotate to dissipate heat.

[0076] Among them, when the rotating device 220 has no fault, the estimated moment of inertia should be within a certain numerical range. When the moment of inertia is not within the numerical range, it can be determined that the moment of inertia at this time meets the preset fault condition, and then it can be determined that the rotating device 220 has a fault.

[0077] The electric tool provided in the embodiment of the present application estimates the rotational inertia of the cutting motor in real time when the cutting motor drives the cutting blade to perform a cutting action, so as to detect whether the cutting blade is missing or damaged based on the rotational inertia of the cutting motor. Therefore, when it is determined that the cutting blade is missing or damaged, the cutting motor can be promptly controlled to stop running, and the cutting blade fault detection can be achieved through the rotational inertia of the cutting motor, thereby improving the reliability of the cutting blade fault detection.

[0078] Exemplarily, the driving mode of the driving motor M2 may be the same as the driving mode of the cutting motor M1 in the above embodiment, that is, the controller 230 may control the driving motor M1 to operate by vector control to realize the function of the electric tool. Fig.10 is a schematic diagram of the structure of another drive motor drive system provided in an embodiment of the present application, combined with Fig. 9 and Fig.10Its driving system can be the same as the driving system structure of the cutting motor M1, including a controller 230, a power supply device 240, a driving circuit 250 for driving the driving motor M2, and a parameter acquisition module 260, and the controller 230 can be integrated with a vector control system, specifically including a speed PI controller 231, a signal processing module 232 (including a speed and position estimation module 2321, a Clark transformation module 2322 and a Park transformation module 2323), a q-axis PI controller 233, a d-axis PI controller 234, a Park inverse transformation module 235 and a SVPWM module 236. The relevant principles can be referred to the description of the cutting motor M1, which will not be repeated here.

[0079] Similarly, based on the above embodiment, the controller 230 may be configured with a rotational inertia estimation module to estimate the rotational inertia of the drive motor M2 according to the mechanical data of the drive motor M2. The present application embodiment does not specifically limit the method for estimating the rotational inertia, and exemplary methods may include recursive least squares identification method, model reference adaptive method, extended Kalman filter method, etc.

[0080] Optional, reference Fig.10 , the controller 230 is configured to estimate the moment of inertia of the driving motor M2 by a recursive least squares identification method.

[0081] Exemplarily, the controller 230 may include a first moment of inertia estimation module 237, which can estimate the moment of inertia of the cutting motor by a recursive least squares identification method. The specific estimation principle can refer to the relevant description of estimating the moment of inertia of the cutting motor M1 by a recursive least squares identification method in the above embodiment, which will not be repeated here.

[0082] Optional, Fig.11 is a structural schematic diagram of another driving system of a driving motor provided in an embodiment of the present application, such as Fig.11 As shown, the controller 230 is configured to estimate the moment of inertia of the drive motor M2 by a model reference adaptive method.

[0083] Exemplarily, the controller 230 may include a second moment of inertia estimation module 238, which can estimate the moment of inertia of the cutting motor by a model reference adaptive method. The specific estimation principle can refer to the relevant description of estimating the moment of inertia of the cutting motor M1 by using the model reference adaptive method in the above embodiment, which will not be repeated here.

[0084] Fig.12 is a model curve diagram for estimating the moment of inertia using the least squares method provided in an embodiment of the present application, Fig.13 is a model curve diagram of the instant application using the model reference adaptive method to estimate the moment of inertia, see Fig.12and Fig.13 As shown in the figure, the motor fan is tested, the motor speed is set to 15000rpm, the gain factor β is 100, and the forgetting factor λ is 0.95. Both the least squares method and the model reference adaptive method can achieve fast and accurate identification and tracking. Fig.12 and Fig.13 As shown, when the motor fan is normal, the estimated moment of inertia of the motor output shaft is 5*10 -6 kg*m 2 At 0.15s, the moment of inertia suddenly changes to 8*10 -6 kg*m 2 .pass Fig.12 and Fig.13 It can be seen that when the motor fan fails, the rotational inertia of the motor output shaft will change significantly. By estimating the rotational inertia of the motor output shaft, the fault detection of the cutting blade is realized, which improves the reliability of the fault detection of the cutting blade.

[0085] Based on the same inventive concept, the embodiment of the present application also provides a lawn mower, comprising: a power supply device, at least for supplying power to a cutting motor; a cutting assembly, comprising a cutting disc, a plurality of cutting blades arranged on the cutting disc, and a cutting motor for driving the cutting blades to perform a cutting action; and a controller, configured to estimate the moment of inertia of the cutting motor through a Kalman prediction unit, and control the operation of the cutting motor based on the moment of inertia. The Kalman prediction unit estimates the moment of inertia of the cutting motor through an extended Kalman filter algorithm.

[0086] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A lawn mower, characterized in that: include: A cutting assembly, comprising at least one cutting blade and a cutting motor for driving the cutting blade to perform a cutting action; A power supply device, at least used to supply power to the cutting motor; The controller is configured to estimate the moment of inertia of the cutting motor and control the operation of the cutting motor according to the moment of inertia.

2. The lawn mower according to claim 1, characterized in that The controller controls the cutting motor to operate in a vector control manner to achieve the function of the lawn mower.

3. The lawn mower according to claim 1, characterized in that: The controller is configured to estimate the moment of inertia of the cutting motor by a model reference adaptive method.

4. The lawn mower according to claim 1, characterized in that The controller is configured to estimate the moment of inertia of the cutting motor by a recursive least squares identification method.

5. The lawn mower according to claim 1, characterized in that The controller is configured to determine whether the cutting blade is faulty according to the moment of inertia, and control the cutting motor to stop running when it is determined that the cutting blade is faulty.

6. The lawn mower according to claim 5, characterized in that The controller is configured to determine that the cutting blade is faulty when the moment of inertia satisfies a preset fault condition.

7. An electric tool, characterized in that: include: a drive motor including an output shaft; A rotating device, disposed on the output shaft and driven to rotate by the output shaft; The controller is configured to estimate the rotational inertia of the drive motor and estimate the state change of the rotating device according to the change of the rotational inertia.

8. The electric tool according to claim 7, characterized in that: The controller controls the operation of the driving motor by means of vector control to realize the function of the electric tool.

9. The electric tool according to claim 7, characterized in that: The controller is configured to estimate the rotational inertia of the drive motor by a model reference adaptive method.

10. The electric tool according to claim 7, characterized in that: The controller is configured to estimate the rotational inertia of the drive motor by a recursive least squares identification method.

11. The electric tool according to claim 7, characterized in that: The controller is configured to determine whether the rotating device fails according to the rotational inertia, and control the driving motor to stop running when it is determined that the rotating device fails.

12. The electric tool according to claim 11, characterized in that: The controller is configured to determine that the rotating device is faulty when the moment of inertia satisfies a preset fault condition.

13. The electric tool according to claim 7, characterized in that: The rotating device comprises a fan or a cutting blade.

14. A lawn mower, characterized in that: include: A power supply device, at least used to supply power to the cutting motor; A cutting assembly, comprising a cutting disc, a plurality of cutting blades arranged on the cutting disc, and a cutting motor driving the cutting blades to perform cutting actions; The controller is configured to estimate the moment of inertia of the cutting motor by a Kalman prediction unit and control the operation of the cutting motor based on the moment of inertia.

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