A method and device for identifying motor stall, and a mower

Abstract

The application discloses a kind of motor stall identification method, identification device and mower, to solve the technical problems of false alarm and poor timeliness caused by relying on current to judge motor stall in prior art.A kind of motor stall identification method is proposed in the application, with variables x and y, comprising the following steps: obtaining the first signal and the second signal generated based on motor rotation, the high band duration of the first signal and the second signal partially overlaps;When the first signal jumps from high band to low band or from low band to high band, identify the band where the second signal is located, and increase or decrease x based on the high and low of the band where the second signal is located after assigning x to y;Periodically obtain the difference A of x-y and the positive and negative value C of motor stall, generate stall signal based on the same or different of A and C positive and negative;Assign y to x.The application also proposes an identification device and a mower, each having components for implementing the above motor stall identification method.

Description

Technical Field

[0001] This invention relates to the field of motor testing technology, and in particular to a method, device and lawnmower for identifying motor stall. Background Technology

[0002] A smart lawnmower consists of a mowing mechanism and a lifting motor. The mowing mechanism adjusts its working height using the lifting motor to adapt to the requirements of different lawn environments.

[0003] The operation of lifting motors is generally divided into manual operation and automatic operation. Among them, manual operation is more cumbersome and less precise, and has become marginalized.

[0004] The automatic lifting of the lifting motor in smart lawnmowers follows a similar control approach across different manufacturers: using Hall effect sensors to generate Hall mileage signals based on the Hall signals produced by the rotation of the lifting motor, thereby identifying the current height position of the mowing mechanism driven by the lifting motor.

[0005] However, the limit position detection at the bottom and top of the lawnmower mechanism usually relies on the sharp increase in current caused by the stalling of the lifting motor at the limit position. Once the system detects that the current exceeds a threshold, it determines that the lawnmower mechanism has reached the bottom or top limit position and stops the lifting motor.

[0006] However, motors also draw a large current during startup, and they can experience a sudden surge in current when subjected to a heavy load for a short period. Using the motor's current threshold to determine if it is stalled makes it difficult to reliably distinguish between stalled operation and the aforementioned high-current conditions, leading to false alarms when relying on current to determine stall status.

[0007] Of course, false alarms can be reduced by increasing the current threshold, but this makes it difficult to stop the machine in time when the motor actually stalls, resulting in poor timeliness. Summary of the Invention

[0008] To overcome the shortcomings of the prior art, this invention proposes a method, device, and lawnmower for identifying motor stall, thereby solving the technical problems of relying on current to determine motor stall, which leads to false alarms and poor timeliness.

[0009] To achieve the above technical objectives, this invention proposes a method for identifying motor stall, which pre-sets variables x and y, and the identification method includes the following steps: S100: Acquire a first signal and a second signal generated by two detection devices based on the rotation of the motor, respectively. The first signal and the second signal both fluctuate periodically and have high-frequency bands and low-frequency bands, and the duration of the high-frequency bands of the two signals partially overlaps. S200: When the first signal jumps from a high band to a low band or from a low band to a high band, identify the band in which the second signal is located, assign x to y, and then increase or decrease x based on the high or low band in which the second signal is located. S300: Based on the detection cycle, periodically acquire the values ​​of x and y to obtain the difference A between x and y; generate the positive and negative values ​​of motor stall C based on the forward and reverse rotation of the motor; and generate a stall signal based on the similarity or difference between the positive and negative values ​​of A and C. S400, Assign the value of y to x.

[0010] The proposed method for identifying motor stall involves acquiring two periodic signals generated by motor rotation using two detection devices. The method updates variables by utilizing the frequency band of the other signal during signal transitions. Then, it compares the difference between the two variables within the detection period with a preset value based on the current rotation direction to determine whether the motor is stalled. This method does not rely on current magnitude for identification, thus avoiding false alarms caused by high-current non-stall conditions such as motor start-up and short-term high loads. It also avoids sacrificing detection timeliness by increasing the current threshold. Furthermore, it can quickly output a stall signal after stalling occurs, balancing detection accuracy and response timeliness. Meanwhile, since only step S100 in the identification method of the present invention needs to be continuously executed, while other core steps for identifying motor stall are executed periodically, the identification method of the present invention will not significantly increase hardware costs due to the addition of stall identification function.

[0011] Preferably, the interval of the detection cycle is T1, and the sum of the durations of a high-frequency band and a low-frequency band of the first signal is T2, where T1 ≤ T2.

[0012] By adopting the aforementioned technical solution, the frequency of the detection cycle can be kept no higher than the change cycle of the first signal, thus avoiding missing signal changes due to excessively long detection intervals. This ensures that signal changes in each cycle can be captured and detected in a timely manner, further improving the response speed of stall detection and preventing missed detection of stall conditions.

[0013] As a preferred option, T1 > T2 / 2.

[0014] By adopting the aforementioned technical solution, at most two detections are generated within one cycle of the first signal, thereby reducing the detection frequency. This not only reduces the computing power load required for identification, but also reduces the impact of A=0 in other detection results besides the first detection caused by multiple detections within one cycle, further reducing false alarms due to stalling.

[0015] As a preferred option, a stall variable N is also preset. The identification method, following S300, also includes the following steps: S500: After S300 generates a stall signal, N=N+m is assigned. The motor stops rotating when N reaches a preset threshold.

[0016] By adopting the aforementioned technical solution, misjudgments caused by single detection errors can be avoided, further improving the accuracy of stall detection and reducing the probability of false shutdown. At the same time, it can also ensure that shutdown can be triggered after only a few detections after stall occurs, without excessive delay in shutdown response, thus balancing detection accuracy and timeliness.

[0017] Preferably, the following steps are included before S100: S010. When the motor starts, the stall variable N is reset to zero.

[0018] By adopting the aforementioned technical solution, it can be ensured that the stall variable N is in its initial state after each motor start-up, avoiding the influence of the residual N value from the previous operation on the current detection result, ensuring that the judgment logic of each stall detection is stable and reliable, and preventing abnormal situations such as premature shutdown before the threshold is reached, or requiring multiple detections to trigger shutdown after stall occurs.

[0019] Preferably, the following steps are included after S500: S510. When no stall signal is generated during the execution of S300, the stall variable N is reset to zero.

[0020] By adopting the aforementioned technical solution, if the motor only experiences a momentary speed fluctuation and a single misjudged stall signal occurs, N can be reset to zero after subsequent detection returns to normal. This avoids the N value from multiple momentary fluctuations accumulating to reach the threshold and causing unnecessary shutdowns, further improving the reliability of detection. It is suitable for speed fluctuation conditions when the motor is running under load, reducing unnecessary shutdowns that affect normal operation.

[0021] Preferably, the following steps are included after S500: When S600 or S500 is executed to stop the motor rotation, the stall variable N is reset to zero.

[0022] By adopting the aforementioned technical solution, the stall variable N can be reset in a timely manner after the motor is stopped. This allows the detection logic to restart from the initial state after the user restarts the motor, and the stall detection will not be affected by the residual N value before the shutdown, ensuring that the detection logic can operate normally after each restart.

[0023] Preferably, the detection device is a Hall effect device, the first signal and the second signal are both Hall level signals, the high band is a high level band, and the low band is a low level band.

[0024] The aforementioned technical solution uses the level signal of the motor's built-in dual Hall effect device to detect motor stall. No additional detection hardware or circuit modification is required. Therefore, it does not significantly increase the manufacturing cost of the motor. This identification method is compatible with most mass-produced forward and reverse motors with dual Hall effect detection, has good compatibility, and low modification cost, which can further alleviate the cost pressure caused by adding motor stall detection function.

[0025] The present invention also proposes a motor stall identification device for performing the identification method described in any of the foregoing technical solutions, the identification device comprising: The acquisition module acquires the first signal and the second signal; and, The control module receives a first signal and a second signal, identifies the band of the second signal when the first signal jumps, assigns a value to the variable x or y, obtains the values ​​of variables x and y, obtains the values ​​of A and C, compares the signs of A and C, and generates a stall signal based on the similarity or difference of the signs of A and C.

[0026] The motor stall identification device proposed in this invention is used to perform the identification method of any of the aforementioned technical solutions, and therefore the identification device has all the technical effects of all the aforementioned identification methods.

[0027] Preferably, the detection device is a Hall effect device, the first signal and the second signal are both Hall level signals, the high band is a high level band, and the low band is a low level band.

[0028] The present invention also proposes a lawnmower, including a housing and a mowing mechanism and a lifting motor housed within the housing. The lifting motor is used for lifting the mowing mechanism. The lawnmower also includes a controller and two Hall effect devices electrically connected to the controller. The two Hall effect devices generate a first signal and a second signal based on the rotation of the lifting motor. The controller is used to implement the motor stall identification method as described in any of the technical solutions.

[0029] The lawnmower proposed in this invention has all the technical effects of the aforementioned identification methods because its controller is used to implement the identification method of any of the aforementioned technical solutions.

[0030] These features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a waveform diagram of the first signal in an embodiment of the present invention; Figure 2 This is a waveform diagram of the second signal in an embodiment of the present invention; Figure 3This is a flowchart of the motor stall identification method in an embodiment of the present invention; Figure 4 This is another flowchart of the motor stall identification method in an embodiment of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other technical solutions obtained by those skilled in the art based on the embodiments without creative effort are all within the protection scope of the present invention.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Furthermore, the terms "first" and "second" (if any) are used to distinguish similar objects, not to describe a specific order or sequence. In the description of this invention, unless otherwise stated, "a plurality of" or "several" means two or more, unless otherwise expressly defined.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] like Figures 1 to 3 As shown in the embodiment of the present invention, a method for identifying motor stall is proposed, which has preset variables x and y, and the identification method includes: S100: Acquire a first signal and a second signal generated by two detection devices based on the rotation of the motor, respectively. Both the first signal and the second signal fluctuate periodically and have high-frequency bands and low-frequency bands, and the duration of the high-frequency bands of the two signals partially overlaps. S200: When the first signal jumps from a high band to a low band or from a low band to a high band, identify the band in which the second signal is located, assign x to y, and then increase or decrease x based on the high or low band in which the second signal is located. S300: Based on the detection cycle, periodically acquire the values ​​of x and y to obtain the difference A between x and y; generate the positive and negative values ​​of motor stall C based on the forward and reverse rotation of the motor; and generate a stall signal based on the similarity or difference between the positive and negative values ​​of A and C. S400, Assign the value of y to x.

[0037] In this method, S100 is executed continuously; S200 is executed after being triggered, and since the first signal is a periodic jump, S200 is executed periodically; S300 is executed periodically; and S400 is executed after S300, so S400 is also executed periodically. In this identification method, only step S100 is executed continuously, while the other steps are executed periodically. Therefore, this identification method has low computational requirements.

[0038] The expression that assigns x to y is y=x, and the expression that assigns y to x is x=y.

[0039] When the motor rotates forward, the waveform of the first signal is as follows: Figure 1 As shown, as the motor rotates, the waveform of the first signal changes periodically along the time axis; the waveform of the second signal is shown in the figure below. Figure 2 As shown, as the motor rotates, the waveform of the second signal changes periodically along the extension direction of the time axis.

[0040] When the motor reverses, the waveform of the first signal follows... Figure 1 The waveform of the second signal changes periodically in the opposite direction to the direction of the time axis extension. Figure 2 The time axis extends in the opposite direction of the periodic change.

[0041] The instantaneous process of a signal transitioning from a high-frequency band to a low-frequency band is called the falling edge (FE), and the instantaneous process of a signal transitioning from a low-frequency band to a high-frequency band is called the rising edge (PE).

[0042] In this embodiment, S200 is executed on the falling edge of the first signal FE.

[0043] When the motor rotates forward, and the first signal is at its falling edge FE, the second signal is in a low-frequency band. After assigning x to y, the value of x is decremented by 1. Therefore, when executing S300, if the motor is not stalled, the obtained x will always be less than y, and the difference A will be negative 1. The motor stall value C, generated based on the motor's forward rotation, is negative; if both A and C are negative, it indicates that the motor is not stalled.

[0044] When the motor reverses, the second signal is in the high-frequency band when the first signal is at the falling edge FE. After assigning y to x, the value of x is incremented by 1. Therefore, when S300 is executed, if the motor is not stalled, the obtained x will always be greater than y, and the difference A will be positive 1. The motor stall value C, generated based on the motor's reverse rotation, is positive; if both A and C are positive, it indicates that the motor is not stalled.

[0045] When a motor stalls, there are two possibilities. First, the motor cannot rotate, and the first signal does not experience a falling edge (FE). This means the identification method does not execute S200. Since step S400 assigns y to x, when S300 is executed, the values ​​of x and y are the same, and the value of A is zero. The signs of A and C are different, thus generating a stall signal. Second, the motor alternates between forward and reverse rotation. The reverse rotation causes the rising edge (PE) and falling edge (FE) of the first signal to interchange, resulting in different signs for A and C, thus generating a stall signal.

[0046] In some other embodiments, adding or subtracting the value of x can also be done by adding or subtracting n. Here, n is a constant, such as a non-zero integer, a decimal, etc.

[0047] In some other embodiments, the band in which the second signal is located can also be identified when the first signal is at the rising edge PE.

[0048] In some other embodiments, x may be subtracted when the second signal is in a high frequency band and added when the second signal is in a low frequency band.

[0049] In this embodiment, as Figure 1 , Figure 2 As shown, the second signal lags behind the first signal by approximately one-quarter of a cycle.

[0050] In some other embodiments, the period of the second signal may lead the period of the first signal; that is, when the motor is rotating forward, the first signal is at the falling edge FE while the second signal is at the high frequency band.

[0051] In some other embodiments, the positive and negative values ​​C and the difference A of the motor stall value can also be configured such that when the motor is not stalled, the two values ​​are opposite; when the motor is stalled, the two values ​​are the same.

[0052] The proposed method for identifying motor stall involves acquiring two periodic signals generated by motor rotation using two detection devices. The method updates variables by utilizing the frequency band of the other signal during signal transitions. Then, it compares the difference between the two variables within the detection period with a preset value based on the current rotation direction to determine whether the motor is stalled. This method does not rely on current magnitude for identification, thus avoiding false alarms caused by high-current non-stall conditions such as motor start-up and short-term high loads. It also avoids sacrificing detection timeliness by increasing the current threshold. Furthermore, it can quickly output a stall signal after stalling occurs, balancing detection accuracy and response timeliness. Meanwhile, since only step S100 in the identification method of the present invention needs to be continuously executed, while other core steps for identifying motor stall are executed periodically, the identification method of the present invention will not significantly increase hardware costs due to the addition of stall identification function.

[0053] In one embodiment, such as Figure 3 , Figure 4 As shown, the identification method also presets a stall variable N, and the identification method further includes the following steps after S300: S500: After S300 generates a stall signal, N=N+m is assigned. The motor stops rotating when N reaches a preset threshold.

[0054] In this embodiment, the value of m is 1. The initial value of N is 0, and the preset threshold of N is 5.

[0055] In some other embodiments, the value of m is a constant, such as a non-zero integer, a decimal, etc. The preset threshold is adaptively adjusted according to the value of m.

[0056] The first signal is composed of an adjacent high-frequency band and a low-frequency band, forming one variation cycle. Ideally, the interval between two adjacent detection cycles is the same as the duration of the first variation cycle of the first signal. However, since the motor needs to bear the load, it cannot guarantee that it will rotate at its rated speed throughout the rotation process. When the motor speed slows down for a certain period of time, A=0 may occur, causing a deviation in the sign of A and C. Therefore, by setting a stall variable N, and ensuring that the motor stops rotating only after N reaches a preset threshold, misjudgments caused by single detection errors are eliminated.

[0057] By setting up the above, we can avoid misjudgments caused by single detection errors, further improve the accuracy of stall detection, reduce the probability of false shutdown, and ensure that shutdown can be triggered after only a few detections after stall occurs, without excessive delay in shutdown response, thus balancing detection accuracy and timeliness.

[0058] In this preferred embodiment, such as Figure 4As shown, the identification method further includes the following steps before S100: S010. When the motor starts, the stall variable N is reset to zero.

[0059] This configuration ensures that the stall variable N is in its initial state after each motor start-up, preventing residual N values ​​from the previous run from affecting the current detection result. It also ensures that the judgment logic for each stall detection is stable and reliable, preventing abnormal situations such as premature shutdown before the threshold is reached or multiple detections required to trigger shutdown after stall occurs.

[0060] In another preferred embodiment, such as Figure 3 As shown, the identification method further includes the following steps after S500: S510. When no stall signal is generated during the execution of S300, the stall variable N is reset to zero.

[0061] With this setting, if the motor only experiences a momentary speed fluctuation and a single false stall signal occurs, N can be reset to zero after subsequent detection returns to normal. This avoids the N value from multiple momentary fluctuations accumulating to reach the threshold and causing unnecessary shutdowns, further improving the reliability of detection. It is suitable for speed fluctuation conditions when the motor is running under load, reducing unnecessary shutdowns that affect normal operation.

[0062] In another preferred embodiment, such as Figure 3 As shown, the identification method further includes the following steps after S500: After executing S600 and S500 to stop the motor rotation, the stall variable N is reset to zero.

[0063] This setting allows the stall variable N to be reset promptly after the motor stops, ensuring that the detection logic can restart from its initial state after the motor is restarted. This prevents the stall detection from being affected by residual N values ​​before shutdown, guaranteeing that the detection logic runs normally after each restart.

[0064] In one embodiment, such as Figure 1 , Figure 2 As shown, the interval of the detection period is T1, and the sum of the durations of a high-frequency band and a low-frequency band of the first signal is T2, where T1 ≤ T2.

[0065] The interval T1 of the detection cycle refers to the time between two adjacent detections.

[0066] This setting ensures that the frequency of the detection cycle is no higher than the change cycle of the first signal, avoiding missing signal changes due to excessively long detection intervals, guaranteeing that signal changes in each cycle can be captured and detected in a timely manner, further improving the response speed of stall detection, and preventing missed detection of stall conditions.

[0067] It should be noted that when T1=T2, the detection cycle is synchronized with the first signal cycle, and signal changes in each cycle can be captured and detected in a timely manner. However, T1=T2 is an ideal state and difficult to achieve in actual working conditions. To avoid missing signal changes, T1<T2 is configured in actual working conditions to reduce false alarms. When T1<T2, there may be multiple detections within a certain cycle of the first signal. When the motor stalls, multiple detections within the same cycle of the first signal may result in A=0, leading to a stall judgment. By using a preset stall variable N and a preset threshold for N, stall shutdown can be avoided within a single signal cycle, reducing false alarms. When the motor is not stalled, the preset stall variable N and the preset threshold for N can eliminate the impact of A=0 in the second detection due to two detections within a cycle, thereby reducing false stall alarms.

[0068] In this preferred embodiment, T1 > T2 / 2.

[0069] In this way, at most two detections are generated within one cycle of the first signal, thereby reducing the detection frequency. This reduces the computational load required for identification and also reduces the impact of A=0 in the other detection results besides the first detection caused by multiple detections within one cycle, further reducing false alarms due to stalling.

[0070] In this embodiment, T2 is 60ms and T1 is 50ms.

[0071] In one embodiment, the detection device is a Hall effect device, and both the first signal and the second signal are Hall level signals, with the high band being a high-level band and the low band being a low-level band.

[0072] To determine the number of rotations of the motor shaft, motors typically have built-in Hall effect sensors. However, a motor equipped with two Hall effect sensors can not only identify the number of rotations but also the direction of rotation. Therefore, motors capable of both forward and reverse rotation are usually equipped with dual Hall effect sensors.

[0073] The identification method in this embodiment detects motor stall based on the level signal of the dual Hall effect device built into the motor. It does not require additional detection hardware or circuit modification, so it does not significantly increase the manufacturing cost of the motor. This makes the identification method compatible with most mass-produced forward and reverse motors with dual Hall effect detection. It has good compatibility and low modification cost, which can further reduce the cost pressure caused by adding motor stall detection function.

[0074] In this embodiment, multiple permanent magnets are spaced apart circumferentially on the motor shaft. As the motor shaft rotates 360°, the first and second signals change periodically multiple times. The number of permanent magnets is Z, and the Z permanent magnets are evenly spaced, such that the phase difference between two adjacent permanent magnets is 360° / Z. The two Hall devices have a phase difference greater than zero and less than 360° / Z.

[0075] This invention also proposes a motor stall identification device for executing the identification method described in any of the foregoing embodiments. The identification device includes an acquisition module and a control module. The acquisition module is used to acquire a first signal and a second signal. The control module is used to receive the first signal and the second signal and, when the first signal jumps, to identify the band in which the second signal is located. The control module is also used to assign values ​​to variables x or y, acquire the values ​​of variables x and y, acquire the values ​​of A and C, compare the signs of A and C, and generate a stall signal based on the similarity or difference of the signs of A and C.

[0076] In some embodiments, the control module is further configured to assign a value to a preset stall variable N, and issue a motor stop command after the stall variable N reaches a preset threshold.

[0077] In some embodiments, the control module is also used to assign a zero value to a preset stall variable N.

[0078] The present invention also proposes a lawnmower, including a housing and a mowing mechanism and a lifting motor housed within the housing. The lifting motor is used for lifting the mowing mechanism. The lawnmower also includes a controller and two Hall effect devices electrically connected to the controller. The two Hall effect devices generate a first signal and a second signal based on the rotation of the lifting motor. The controller is used to implement the motor stall identification method as described in any of the foregoing embodiments.

[0079] In this embodiment, the controller includes the acquisition module and control module of the foregoing embodiments.

[0080] The controller controls the lifting motor to rotate forward or backward to drive the mowing mechanism to rise and fall. When the mowing mechanism rises and falls inside the housing and is stopped at the bottom or top of the housing, the lifting motor stalls. When the controller detects that the lifting motor is stalled, it stops the lifting motor. The controller can determine whether the mowing mechanism has descended to the bottom or risen to the top based on the forward or reverse rotation of the lifting motor.

[0081] During the raising and lowering process of the mowing mechanism, hay mixed into the housing can easily generate resistance during the raising and lowering process, affecting the controller's judgment of whether the mowing mechanism has reached the correct position. The probability of false judgment can be reduced by reasonably setting the stall variable N and the preset threshold of N in the aforementioned embodiments.

[0082] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A method for identifying motor stall, characterized in that, Given variables x and y, the identification method includes the following steps: S100: Acquire a first signal and a second signal generated by two detection devices based on the rotation of the motor, respectively. The first signal and the second signal both fluctuate periodically and have high-frequency bands and low-frequency bands, and the duration of the high-frequency bands of the two signals partially overlaps. S200: When the first signal jumps from a high band to a low band or from a low band to a high band, identify the band in which the second signal is located, assign x to y, and then increase or decrease x based on the high or low band in which the second signal is located. S300: Based on the detection cycle, periodically acquire the values ​​of x and y to obtain the difference A between x and y; generate the positive and negative values ​​of motor stall C based on the forward and reverse rotation of the motor; and generate a stall signal based on the similarity or difference between the positive and negative values ​​of A and C. S400, Assign the value of y to x.

2. The identification method as described in claim 1, characterized in that, The interval of the detection cycle is T1, and the sum of the durations of a high-frequency band and a low-frequency band of the first signal is T2, where T1 ≤ T2.

3. The identification method as described in claim 2, characterized in that, T1 > T2 / 2.

4. The identification method as described in claim 1, characterized in that, It also pre-determines the stall variable N. The identification method, following S300, also includes the following steps: S500: After S300 generates a stall signal, N=N+m is assigned. The motor stops rotating when N reaches a preset threshold.

5. The identification method as described in claim 4, characterized in that, The following steps are included before S100: S010. When the motor starts, the stall variable N is reset to zero.

6. The identification method as described in claim 4, characterized in that, The following steps are included after S500: S510. When no stall signal is generated during the execution of S300, the stall variable N is reset to zero.

7. The identification method as described in claim 4, characterized in that, The following steps are included after S500: When S600 or S500 is executed to stop the motor rotation, the stall variable N is reset to zero.

8. The identification method as described in claim 1, characterized in that, The detection device is a Hall effect device, and both the first signal and the second signal are Hall level signals. The high band is a high-level band, and the low band is a low-level band.

9. A device for identifying motor stall, characterized in that, For performing the identification method as described in any one of claims 1 to 8, the identification device comprises: The acquisition module acquires the first signal and the second signal; and, The control module receives a first signal and a second signal, identifies the band of the second signal when the first signal jumps, assigns a value to the variable x or y, obtains the values ​​of variables x and y, obtains the values ​​of A and C, compares the signs of A and C, and generates a stall signal based on the similarity or difference of the signs of A and C.

10. A lawnmower, comprising a housing and a mowing mechanism and a lifting motor housed within the housing, the lifting motor being used for lifting the mowing mechanism, characterized in that, It also includes a controller and two Hall effect devices electrically connected to the controller, the two Hall effect devices generating a first signal and a second signal based on the rotation of the lifting motor, the controller being used to implement the motor stall identification method as described in any one of claims 1 to 8.

Images