Control method and control system of electric tool and electric tool

Abstract

The invention provides a control method and system of an electric tool and the electric tool, the electric tool comprises an electric tool body, an accelerometer and a gyroscope which are arranged in the electric tool body, and a processor arranged in the electric tool, and the processor is electrically connected with the accelerometer, the gyroscope and a motor. In the working process of the electric tool body, the accelerometer and the gyroscope are used for carrying out motion detection, the processor is used for carrying out data processing to obtain accurate motion data, the accurate motion data are compared with the set threshold value to judge whether braking protection needs to be executed or not, and when the motion state of the electric tool is abnormal, shutdown can be carried out in time; the injury to personnel is avoided, and the use safety of the electric tool is improved.

Description

Technical Field

[0001] The present invention belongs to the field of motor control, and particularly relates to a control method, a control system and a power tool for a power tool. Background Art

[0002] When a power tool is in operation, various uncertain and uncontrollable situations may occur. For example, when using a chainsaw for cutting work, when the top of the saw chain or the leading guide plate touches a hard material or the operator's operating posture is incorrect, etc., the kinetic energy recoil caused by the instantaneous increase in cutting resistance will result in a relatively high instantaneous impact speed, causing the tool to rebound violently. Since the traditional braking method has hysteresis and cannot brake in time when recoil occurs, recoil accidents can cause limb injuries and equipment damage in minor cases, and even cause casualties in severe cases. Therefore, an efficient and reliable braking control method must be adopted to effectively prevent the occurrence of recoil accidents.

[0003] In some existing power tools, a gyroscope is used to measure the angular velocity in three coordinate axes during movement and compare it with a threshold value to determine whether to perform braking. However, due to the complex actual movement trajectory of the machine, there may be an angle between its movement plane and the coordinate axes, and there is a certain deviation between the angular velocity value measured by the gyroscope and the actual angular velocity value, which may lead to the inability to judge the abnormal state in time and perform braking, thus reducing the sensitivity of protection. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a control method, a control system and a power tool for a power tool, which adopt a two-in-one intelligent module of a gyroscope and an accelerometer to achieve intelligent three-axis anti-kick braking. When the power tool encounters sudden rebound, rapid flipping, displacement, etc., it can accurately calculate the change information of the relative position of the power tool, analyze and compare the change data, and then perform rapid braking control, so as to obtain safer and more intelligent multiple danger protection and anti-fool protection, and improve the safety of using the power tool.

[0005] To achieve the above object and other related objects, the present invention provides a control method for a power tool, including:

[0006] Receiving a motor start signal;

[0007] According to the start signal, collecting the acceleration values of a three-axis accelerometer and calculating to obtain the corresponding angle values;

[0008] According to the start signal, collecting and obtaining the angular velocity values of a three-axis gyroscope;

[0009] Calculating and obtaining the actual angular velocity of the power tool movement according to the angle values and the angular velocity values;

[0010] When the actual angular velocity is greater than the first preset threshold, control the counter value to be incremented by one; otherwise, clear the counter value to zero.

[0011] When the counter value is greater than the second preset threshold, send a stop command to the motor to control the motor to stop running; when the counter value is not greater than the second preset threshold, then obtain the angle value and the angular velocity value again.

[0012] In an alternative embodiment of the present invention, the angle value includes a first angle value, a second angle value, and a third angle value corresponding to three axes of a triaxial accelerometer, and the angular velocity value includes a first angular velocity value, a second angular velocity value, and a third angular velocity value corresponding to three planes of a triaxial gyroscope. Among them, the steps of calculating the actual angular velocity of the power tool movement based on the angle value and the angular velocity value include:

[0013] Calculate and obtain a first actual angular velocity based on the first angle value and the first angular velocity value;

[0014] Calculate and obtain a second actual angular velocity based on the second angle value and the second angular velocity value;

[0015] Calculate and obtain a third actual angular velocity based on the third angle value and the third angular velocity value.

[0016] In an alternative embodiment of the present invention, the steps of when the actual angular velocity is greater than the first preset threshold, controlling the counter value to be incremented by one; otherwise, clearing the counter value to zero include:

[0017] When the first actual angular velocity is greater than the first preset threshold, control the first counter value to be incremented by one; otherwise, clear the first counter value to zero;

[0018] When the second actual angular velocity is greater than the first preset threshold, control the second counter value to be incremented by one; otherwise, clear the second counter value to zero;

[0019] When the third actual angular velocity is greater than the first preset threshold, control the third counter value to be incremented by one; otherwise, clear the third counter value to zero.

[0020] In an alternative embodiment of the present invention, the steps of when the counter value is greater than the second preset threshold, sending a stop command to the motor to control the motor to stop running; when the counter value is not greater than the second preset threshold, then obtaining the angle value and the angular velocity value again include:

[0021] When any one of the first counter, the second counter, and the third counter has a value greater than a second preset threshold, send a stop instruction to the motor to control the motor to stop running; when the values of the first counter, the second counter, and the third counter are all not greater than the second preset threshold, then obtain the angle value and the angular velocity value again.

[0022] The present invention also provides a control method for a power tool, including:

[0023] Receiving a motor start signal;

[0024] Collecting and obtaining the acceleration value of a triaxial accelerometer according to the start signal;

[0025] Collecting and obtaining the angular velocity value of a triaxial gyroscope according to the start signal;

[0026] When the acceleration value is greater than a third preset threshold, control the value of a fourth counter to increase by one, otherwise clear the value of the fourth counter;

[0027] When the angular velocity value is greater than a fourth preset threshold, control the value of a fifth counter to increase by one, otherwise clear the value of the fifth counter;

[0028] When the value of the fourth counter is greater than a fifth threshold or the value of the fifth counter is greater than a sixth threshold, send a stop instruction to the motor to control the motor to stop running; when the value of the fourth counter is not greater than the fifth threshold and the value of the fifth counter is not greater than the sixth threshold, then obtain the acceleration value and the angular velocity value again.

[0029] In an optional embodiment of the present invention, the step of collecting and obtaining the acceleration value of a triaxial accelerometer according to the start signal includes:

[0030] Collecting the static value of the triaxial accelerometer when the power tool starts according to the motor start signal;

[0031] Collecting the real-time acceleration value of the triaxial accelerometer after a preset time interval;

[0032] Obtaining the difference between the real-time acceleration value and the static value as the acceleration value.

[0033] The present invention also provides a control system for a power tool, including:

[0034] A data acquisition module, configured to receive a motor start signal, collect the acceleration value of a triaxial accelerometer according to the start signal and calculate and obtain a corresponding angle value, and collect and obtain the angular velocity value of a triaxial gyroscope according to the start signal;

[0035] An angular velocity calculation module, configured to calculate and obtain the actual angular velocity of the power tool's movement based on the angle value and the angular velocity value;

[0036] A counting module, configured to compare the actual angular velocity with a first preset threshold. When the actual angular velocity is greater than the first preset threshold, control the counter value to increment by one; otherwise, clear the counter value;

[0037] A control module, configured to send a stop instruction to the motor and control the motor to stop running when the counter value is greater than a second preset threshold.

[0038] The present invention also provides a power tool, including:

[0039] A power tool body, an accelerometer and a gyroscope disposed within the power tool body, and a processor disposed within the power tool;

[0040] The processor is electrically connected to the accelerometer, the gyroscope, and the motor, and the processor is configured to execute the control method of the power tool as described in any one of the above embodiments.

[0041] In an optional embodiment of the present invention, the power tool is any one of a chain saw and a hand saw.

[0042] In an optional embodiment of the present invention, the accelerometer is a three-axis accelerometer, and the gyroscope is a three-axis gyroscope.

[0043] The technical effect of the present invention is that in the control method of the present invention, an actual angular velocity calculation method based on the fusion of acceleration and gyroscope is adopted to improve the accuracy of the shutdown criterion. Threshold judgment is performed by combining motion data and a filter counter to achieve fast response while ensuring normal working efficiency; the control system of the present invention can accurately monitor the motion state of the power tool. When it suddenly encounters rapid rebound, flipping, or displacement during work, it can provide intelligent braking control to improve the safety of user operation; the power tool combines mechanical braking and electronic braking, and manual operation and intelligent control, enabling effective braking control and safe and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 It is a schematic diagram of the overall structure of a chain saw in an embodiment of the present invention;

[0046] Figure 2 Schematic structural diagram of another perspective of the chainsaw in an embodiment of the present invention

[0047] Figure 3 Schematic local structural diagram of the chainsaw in an embodiment of the present invention;

[0048] Figure 4 Schematic local structural diagram of the chainsaw in an embodiment of the present invention;

[0049] Figure 5 Schematic structural diagram of the position processing unit and the motor control unit of the chainsaw in an embodiment of the present invention;

[0050] Figure 6 Block diagram of the control system of the power tool in an embodiment of the present invention;

[0051] Figure 7 Working flowchart of the control system of the power tool in an embodiment of the present invention;

[0052] Figure 8 Schematic flowchart of the control method of the power tool in an embodiment of the present invention;

[0053] Figure 9 Schematic flowchart of step S140 of the control method of the power tool in an embodiment of the present invention;

[0054] Figure 10 Schematic flowchart of step S150 and step S160 of the control method of the power tool in an embodiment of the present invention;

[0055] Figure 11 Working flowchart of the control system of the power tool in another embodiment of the present invention;

[0056] Figure 12 Schematic flowchart of the control method of the power tool in another embodiment of the present invention.

[0057] Reference numeral description:

[0058] 100, housing; 200, cutting part; 300, battery pack; 400, position processing unit; 500, motor control unit; 600, motor; 700, switch; 800, mechanical braking unit; 410, sensor module;

[0059] 10, control system; 11, data acquisition module; 12, angular velocity calculation module; 13, counting module; 14, control module. Detailed implementation manners

[0060] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0061] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0062] Generally, mechanical brakes and electronic brake switches are provided in handheld power tools such as chain saws and one-handed saws, and users need to manually operate for braking. However, for sudden abnormal motion situations such as sudden rebound, rapid rollover, or displacement of the power tool, users may not be able to react and operate in time for braking. To ensure the safety of power tool use, it is necessary to detect the motion state of the power tool through an intelligent control system and take braking measures in a timely manner. Generally, sensors such as gyroscopes are often used to detect the motion angular velocity of the power tool and compare it with a set threshold to determine whether abnormal motion occurs. However, in complex motion scenarios, the actual motion trajectory of the power tool is complex and there is an angle with the coordinate axis. The angular velocity measured by the gyroscope cannot directly reflect the true motion state, which may lead to failure or delay in threshold judgment. To avoid the occurrence of dangerous situations, higher requirements are put forward for the accuracy and sensitivity of motion detection.

[0063] Please refer to Figures 1 to 5 , the present invention provides a power tool, including a power tool body, an accelerometer and a gyroscope provided in the power tool body, and a processor provided in the power tool; the processor is electrically connected to the accelerometer, the gyroscope, and the motor. The processor is used to execute the control method of the power tool, perform real-time motion monitoring during the working process of the power tool, and implement intelligent braking. During the working process of the power tool body, the accelerometer and the gyroscope are used for motion detection, and data processing and threshold comparison are performed through the processor to determine whether braking protection needs to be executed. When the motion state of the power tool is abnormal, the processor can timely send a shutdown signal for shutdown, avoiding harm to personnel when the power tool continues to operate in an abnormal state, and improving the safety of power tool use.

[0064] Please refer to Figures 1 to 5, in an alternative embodiment of the present invention, the accelerometer is a three-axis accelerometer, the gyroscope is a three-axis gyroscope, and the three-axis accelerometer and the three-axis gyroscope are integrated into a sensor module and installed in the power tool, reducing the installation space occupied, and at the same time enabling more accurate motion measurement and calculation. It can be understood that when using a handheld power tool, it generally rotates around a certain point, and the operation is carried out by controlling the movement of the power tool body on multiple axes. For example, when using a chainsaw, it generally rotates around the base of the grip as the center of motion for up-and-down cutting motion or horizontal cutting, etc. The sensor module is arranged at a place far from the center of motion on the main motion axis to ensure accurate data measurement.

[0065] Please refer to Figures 1 to 5 , in an alternative embodiment of the present invention, the power tool can be any one of a chainsaw and a one-handed saw. The following takes a chainsaw as an example to elaborate on the technical solution in detail. It should be noted that this solution can also be applied to other handheld power tools such as electric planers and electric drills to achieve effective intelligent braking and improve the safety of using the power tool.

[0066] Please refer to Figures 1 to 5 , in an alternative embodiment of the present invention, the chainsaw includes a chainsaw body, and the chainsaw body includes a housing 100 and a cutting part 200. The cutting part 200 is installed at the front end of the housing 100. An operation handle is also provided outside the housing 100 for holding and operating the chainsaw for cutting work; it also includes a battery pack 300, a position processing unit 400, and a motor control unit 500 arranged in the housing 100. The battery pack 300 is used to provide power for the control system, and the position processing unit 400 and the motor control unit 500 are used to realize the control of the power tool to perform operations such as starting or braking.

[0067] Please refer to Figures 1 to 5 , in an alternative embodiment of the present invention, the position processing unit 400 communicates with the motor control unit 500. When the motor 600 starts, a start signal is sent from the motor control unit 500 to the position processing unit 400. During the operation of the motor 600, the position processing unit 400 continuously collects and processes the motion data of the chainsaw and judges it with a set threshold. When the actual motion speed exceeds the set threshold and lasts for a certain time, the braking protection is started, and a stop signal is sent from the position processing unit 400 to the motor control unit 500 to control the motor 600 to stop, and the chainsaw stops running.

[0068] Please refer to Figures 1 to 5, in an alternative embodiment of the present invention, the position processing unit 400 includes a sensor module 410 and a sensor processor. The sensor module 410 includes a three-axis accelerometer and a three-axis gyroscope, and is used to read motion data such as offset angle, linear acceleration, and angular velocity. The sensor processor is connected to the sensor module 410 through an SPI (Serial Peripheral Interface) or IIC (Inter-Integrated Circuit) interface, reads the data of the three-axis accelerometer and the three-axis gyroscope, and can calculate the linear acceleration, angular velocity, linear displacement, or arc displacement of the power tool based on the detected data, obtain an accurate motion trajectory, and accurately judge the motion state of the power tool. Specifically, for example, the actual motion's real-time offset angle values in multiple directions are obtained through the three-axis accelerometer, and the angular velocity on each coordinate axis is obtained using the gyroscope. After the sensor processor reads the data, corresponding data processing and calculations are performed to obtain the angular velocity of the actual motion, and the processed data is compared with a preset threshold. When the actual motion angular velocity continuously exceeds the preset threshold within the filtering time, the sensor processor sends a stop signal to the motor control unit 500, and the motor 600 is controlled to stop running through the motor control unit 500.

[0069] Please refer to Figures 1 to 5 , in an alternative embodiment of the present invention, the motor control unit 500 is used to receive the input of the switch circuit, the displacement information and the stop command of the position processing unit 400, and determine the start or stop, normal operation or braking of the motor 600. Specifically, the motor control unit 500 includes a motor drive circuit, a switch circuit, and a motor processor. The motor processor is connected to the motor 600 through the motor drive circuit to control the operation or stop of the motor 600. At the same time, the motor control unit 500 is connected to the switch 700 through the switch circuit to control the start and stop of the motor 600 through the switch 700. The motor processor realizes communication with the sensor processor through a Uart or RS485 interface. When the motor 600 starts, a motor start signal is sent to the sensor processor through the motor processor, and at the same time, the position detection unit is started for motion detection and judgment; when the position processing unit 400 sends a stop signal to the motor processor through the sensor processor, the motor processor controls the motor 600 to stop. The motor processor and the sensor processor can be integrated into a single MCU (microprocessing unit), which is arranged in the housing 100 and is respectively connected to modules such as the sensor module 410, the switch circuit, and the motor 600, integrating multiple functions such as motor control, data acquisition and calculation, and motion judgment in the microprocessing unit for processing.

[0070] Please refer to Figures 1 to 5, in an alternative embodiment of the present invention, a plurality of switches 700 are provided on the chainsaw to facilitate manual operation for starting or stopping the chainsaw. Specifically, a first switch and a second switch are provided at the position of the main operation handle. The signals of the first switch and the second switch jointly control the start of the motor 600, which is convenient for operation and ensures safety in use. The operating wrench of the first switch is arranged below the handle, and the operating button of the second switch is arranged above the handle, which is convenient for operation. When the wrench and the button are pressed simultaneously to turn on both signal switches 700, the motor control unit 500 starts the motor 600, and the motor 600 drives the rotation of the cutter chain for cutting; when the first switch or the second switch is released, an electronic brake signal is triggered, and the motor control unit 500 controls the motor 600 to stop rotating, realizing shutdown. In addition, a mechanical braking unit 800 is also provided, which cooperates with the electronic braking, and can also be manually controlled to stop through the braking switch during the use of the chainsaw.

[0071] Please refer to Figures 1 to 5 , in an alternative embodiment of the present invention, during the operation of the chainsaw, the cutter chain rotates driven by the motor 600. When it is necessary to stop working, a shutdown signal is sent to the motor processor through the switch circuit for electronic braking to control the motor 600 to stop rotating. For example, the first switch and the second switch can be released to trigger the electronic brake; braking can also be performed through the braking switch. The braking switch is, for example, a protective plate arranged at the front end of the housing. When the protective plate is pushed to the braking position, the braking signal of the braking switch is triggered, and the motor control unit 500 receives the braking signal to control the motor 600 to stop running. At the same time, the mechanical braking module inside the housing 100 is started, and the steel belt on the brake disc is tightened to lock the motor 600 to stop it from running. Under the dual action of electronic and mechanical braking, it is ensured that the motor 600 can stop quickly.

[0072] In addition, during the operation of a chainsaw, if an unexpected situation occurs, for example, when the workpiece has just been cut, the chainsaw may fall due to the sudden disappearance of the resistance of the workpiece, and then quickly advance forward. The user cannot react in time to perform manual braking. When the forward movement amplitude is large, it is very likely to cause accidental cutting of other targets or harm to the user, or the chainsaw may experience recoil during normal operation, causing harm to the user. Since the movement speed of the chainsaw is different under abnormal movements such as falling or recoil compared to normal operation, and during the operation of the chainsaw, the position processing unit 400 continuously detects and calculates the movement through the accelerometer and gyroscope of the sensor module 410 and compares it with a preset threshold. When the chainsaw rushes forward, the position processing unit 400 can timely send a stop signal to the motor control unit 500 through detection and judgment, activate the electronic brake, and control the motor 600 to stop running to avoid accidents. By using an integrated intelligent module of gyroscope and accelerometer, on the basis of the electronic brake, mechanical brake, and electronic and mechanical brake modes of the chainsaw, an intelligent three-axis anti-kick braking mode is provided, effectively reducing the danger of tool use and enabling more safe and intelligent multiple anti-fool protection.

[0073] Please refer to Figure 6 , based on the intelligent braking requirements of the above-mentioned power tools, the present invention proposes a control system 10 for a power tool, which is arranged in a power tool such as a chainsaw and can provide effective intelligent braking control for the power tool. The control system includes a data acquisition module 11, an angular velocity calculation module 12, a counting module 13, and a control module 14. Among them, the data acquisition module 11 is used to receive the start signal of the motor, collect the acceleration values of the three-axis accelerometer according to the start signal and calculate the corresponding angle values, and collect and obtain the angular velocity values of the three-axis gyroscope according to the start signal; the angular velocity calculation module 12 is used to calculate the actual angular velocity of the movement of the power tool according to the angle values and angular velocity values; the counting module 13 is used to compare the actual angular velocity with a first preset threshold. When the actual angular velocity is greater than the first preset threshold, the value of the counter is incremented by one, otherwise the value of the counter is cleared; the control module 14 is used to send a stop instruction to the motor and control the motor to stop running when the value of the counter is greater than a second preset threshold. By cooperating with the motor unit through this control system, real-time movement detection is performed during the operation of the power tool. When the power tool experiences abnormal movements such as rollover, forward rush, and rebound, the control system can timely detect the movement abnormality and send a stop instruction to the motor to control the motor to stop running, avoiding accidents and effectively improving the safety of tool use.

[0074] Please refer to Figures 1 to 10, based on the above electric tool and control system, the present invention provides a control method for an electric tool. When the electric tool is working, an accelerometer and a gyroscope are used to simultaneously detect its motion state and compare it with a set threshold to judge the motion state. When an abnormal motion state (such as sudden rebound, forward rush, rapid flipping, displacement, etc.) is detected, braking is performed in a timely manner to prevent the electric tool from continuously operating in abnormal states such as forward rush and tumbling, which may cause harm to personnel.

[0075] Please refer to Figures 7 to 10 , the control method of the electric tool includes the following steps:

[0076] S110. Receive a motor start signal;

[0077] S120. According to the start signal, collect the acceleration values of the triaxial accelerometer and calculate the corresponding angle values;

[0078] S130. According to the start signal, collect and obtain the angular velocity values of the triaxial gyroscope;

[0079] S140. Calculate and obtain the actual angular velocity of the electric tool's motion according to the angle values and the angular velocity values;

[0080] S150. When the actual angular velocity is greater than the first preset threshold, control the counter value to be incremented by one, otherwise clear the counter value;

[0081] S160. When the counter value is greater than the second preset threshold, send a stop command to the motor to control the motor to stop running; when the counter value is not greater than the second preset threshold, then obtain the angle values and the angular velocity values again.

[0082] Please refer to Figures 1 to 10 , taking a chainsaw as an example, in step S110, first press the first switch and the second switch on the chainsaw at the same time, and send a motor start signal to the processor of the motor control unit through the switch circuit. After receiving the start signal from the switch circuit, the motor control unit controls the motor to run and sends a start command to the position processing unit through the Uart or RS485 interface. After receiving the start signal, the sensor module of the position processing unit starts to collect the motion data of the chainsaw, and the processor performs data processing and comparison, etc. to judge whether braking protection needs to be executed. During the operation of the motor, the position processing unit continuously collects and processes the motion data and performs braking judgment to achieve effective intelligent braking control during the working process of the chainsaw. When the motor control unit receives the stop signal and controls the motor to stop running, the position processing unit stops running.

[0083] Please refer to Figures 1 to 10, after the position processing unit is started, it continuously collects motion data through the sensor module, and the processor receives the detection data and performs processing and calculations. Since the coordinate system of the sensor is fixed relative to the chainsaw after installation, for example, the X-axis can be defined as the front-back direction of the chainsaw, and the Y-axis can be defined as the left-right direction of the chainsaw to establish a coordinate system. The angular velocity measured by the gyroscope is the angular velocity based on the coordinate system of the sensor itself. When the motion direction of the chainsaw is consistent with the coordinate axis, the motion state of the chainsaw can be accurately judged by comparing the measured angular velocity value with the threshold. However, in actual use, especially when the chainsaw rebounds, rushes forward, flips or other sudden impacts occur, its actual motion direction generally has a certain angle with the coordinate axis. Since the basis for braking judgment is generally to compare the measured angular velocity value with the threshold, but the difference between the angular velocity value measured by the sensor and the actual motion angular velocity value is different when the motion offset angle is different. If the measured angular velocity value is still directly compared with the threshold, the actual motion intensity may be underestimated or overestimated. For example, when the actual motion angular velocity exceeds the threshold, the measured angular velocity value may not reach the threshold, so the abnormal state of the machine cannot be judged in time, resulting in misjudgment and reducing the sensitivity of protection. Therefore, it is necessary to perform fusion processing and calculation on the data measured by the three-axis accelerometer and the three-axis gyroscope, use the accelerometer for angle measurement, compensate the attitude error through coordinate transformation, assist the gyroscope in calculating the angular velocity, obtain a more accurate angular velocity value, and then compare the obtained actual angular velocity value with the threshold to achieve braking control.

[0084] In steps S120 to S140, first, the acceleration values of the three-axis accelerometer are collected according to the start signal, and the corresponding angle values are obtained through calculation. The measured angle values here are the offset angles between the actual motion of the chainsaw and the coordinate axis. It should be noted that when the chainsaw is working, the accelerometer can directly measure the acceleration values on each axis. Based on the ratio of the components on each axis measured by the accelerometer and combined with the arctangent function, the offset angle between the actual motion and the coordinate axis can be obtained. Then, the angular velocity values of the three-axis gyroscope are collected and obtained according to the start signal. Here, the angular velocity values of the three-axis gyroscope can be directly read. Finally, the actual angular velocity of the power tool motion is calculated based on the offset angle value and the angular velocity value. Specifically, for example, if the angle between the actual motion plane of the chainsaw and the X-axis measured by the three-axis accelerometer is θ, and the angular velocity of the X-axis measured by the three-axis gyroscope is ω0, through projection and coordinate transformation, the actual motion angular velocity value ω1 can be calculated by the angular velocity compensation formula ω1 = ω0 / cosθ.

[0085] Please refer to Figure 9, the angle values include the first angle value, the second angle value, and the third angle value corresponding to the three axes of the three-axis accelerometer, and the angular velocity values include the first angular velocity value, the second angular velocity value, and the third angular velocity value corresponding to the three-axis gyroscope in three planes. The actual angular velocity in three motion directions is obtained through data processing and calculation respectively. That is, step S140 includes:

[0086] S141. Calculate and obtain the first actual angular velocity according to the first angle value and the first angular velocity value;

[0087] S142. Calculate and obtain the second actual angular velocity according to the second angle value and the second angular velocity value;

[0088] S143. Calculate and obtain the third actual angular velocity according to the third angle value and the third angular velocity value.

[0089] Specifically, in step S120, the accelerometer can respectively obtain that the included angles between the actual angular velocity and the X-axis, Y-axis, and Z-axis are the first angle value, the second angle value, and the third angle value according to the static gravity component. In step S130, the angular velocities of the X-axis, Y-axis, and Z-axis directly read by the three-axis gyroscope are the first angular velocity value, the second angular velocity value, and the third angular velocity value respectively. Then, according to the above angle compensation formula, the actual angular velocity of the actual motion in three planes is calculated respectively, so as to obtain the actual motion data and motion trajectory of the chainsaw.

[0090] After calculating the actual motion angular velocity, step S150 is executed. The actual motion angular velocity is compared with the preset threshold of the angular velocity. When the actual angular velocity is greater than the first preset threshold, the value of the counter is incremented by one; otherwise, the value of the counter is cleared. It should be noted that during the detection and calculation of the actual angular velocity value, data filtering processing is required for both. Here, the actual angular velocity value is the standard value obtained after filtering processing. It is compared with the first preset threshold and the filter is counted. A stop signal will be sent only when the actual angular velocity is greater than the preset threshold and lasts for a certain period of time to avoid misjudgment. Using multi-sensor detection and fusion calculation to obtain the actual angular velocity value can effectively eliminate the error caused by the inclination of the chainsaw. The accurate angular velocity value can be obtained when the chainsaw moves at any angle, so as to perform accurate trajectory calculation and achieve sensitive detection and effective braking protection.

[0091] Please refer to Figures 9 to 10, in step S140, the triaxial accelerometer and the triaxial gyroscope can respectively detect the offset angles of the actual movement from the three coordinate axes and the angular velocities of the gyroscope on the three axes. After fusing and calculating and filtering these two sets of data to obtain the actual angular velocities in the three directions, in step S150, the actual angular velocities in the three directions are respectively compared with the first preset threshold, and the filter counters are respectively incremented, that is, step S150 includes:

[0092] S151. When the first actual angular velocity is greater than the first preset threshold, control the value of the first counter to be incremented by one; otherwise, clear the value of the first counter.

[0093] S152. When the second actual angular velocity is greater than the first preset threshold, control the value of the second counter to be incremented by one; otherwise, clear the value of the second counter.

[0094] S153. When the third actual angular velocity is greater than the first preset threshold, control the value of the third counter to be incremented by one; otherwise, clear the value of the third counter.

[0095] After the counter counting is completed, step S160 is executed for braking judgment. When the counter value is greater than the second preset threshold, the position processing unit sends a stop instruction to the motor control unit, and the motor control unit controls the motor to stop running to achieve shutdown; when the counter value is not greater than the second preset threshold, the angle value and the angular velocity value are obtained again for data processing and threshold judgment. It can be understood that the position processing unit is consistent with the operation of the motor. During the operation of the motor, the accelerometer and the gyroscope continuously read the motion data and perform data processing through the processor. In step S160, if the counter value is greater than the second preset threshold, a stop instruction is sent to the motor, and at the same time, the position processing unit stops running; when the motor starts again, the position processing unit starts to execute steps S110 to S160 again, and continuously detects the motion of the chainsaw during the operation of the motor.

[0096] In step S160, the actual angular velocity is compared with the first preset threshold at regular intervals, and the filter is counted at the same time. If the actual angular velocity continuously exceeds the first preset threshold within the preset filtering time, it is determined that the chainsaw needs to be braked and protected, and a stop signal is sent to the motor. Specifically, for example, the actual angular velocity and the first preset threshold are compared every 10 milliseconds. The first preset threshold is the angular velocity threshold, and the second preset threshold is the filtering times threshold. For example, the second preset threshold can be set to 10. When the value of the filter counter (filtering times) is greater than ten, a stop signal is sent, that is, a stop signal is sent after the actual angular velocity continuously exceeds the threshold within 100 milliseconds (filtering time). During the threshold comparison process, if the actual angular velocity is less than the first preset threshold midway, the counter is reset and recalculated. By setting and judging the second preset threshold, the speed of the braking response is controlled, realizing intelligent protection while avoiding misjudgment and affecting the normal use of the tool. It can be understood that the lower the filtering time, the shorter the response time, but it may lead to too high sensitivity and easy false triggering. Therefore, the settings of the filtering times and the filtering time need to be reasonably set and adjusted according to the actual application to avoid false triggering while ensuring the protection sensitivity.

[0097] In step S160, the position processing unit monitors the over-threshold states of three planes respectively, and triggering a stop when any plane continuously exceeds the limit. Specifically, the actual angular velocities on the three moving planes are respectively compared with the first preset threshold, and the filter counting is respectively performed. When any one of the values of the first counter, the second counter, and the third counter is greater than the second preset threshold, a stop instruction is sent to the motor to control the motor to stop running, that is, a stop signal is sent when the actual angular velocity in any direction continuously exceeds the first preset threshold within the filtering time, and the braking protection is started; when the values of the first counter, the second counter, and the third counter are not greater than the second preset threshold, the angle value and the angular velocity value are obtained again, and the data processing and threshold comparison are performed again.

[0098] Please refer to Figures 1 to 10 , when the motor control unit receives the stop instruction sent by the position processing unit, it controls the motor to stop running to achieve braking. After the motor stops running, if it needs to be started again, the switch needs to be released first. After releasing the switch circuit signal for a certain time, then press the corresponding switch signal again to achieve a safe restart; after the switch is reset, the motor start signal is sent to the motor control unit again through the switch circuit to control the motor to restart. At the same time, the motor control unit sends the start signal to the position processing unit, and the position processing unit restarts and executes the control process to perform real-time motion detection and braking judgment; if the switch is not reset, the motor control unit will not receive the start signal of the switch circuit, the motor remains in the stopped state, and the position processing unit will not start.

[0099] Please refer toFigures 11 to 12 , the present invention also provides a control method for a power tool, which uses an accelerometer and a gyroscope to detect the linear acceleration and angular velocity in multiple directions respectively, and compares them with corresponding set thresholds to achieve braking judgment. Specifically, the control method of the power tool includes the following steps:

[0100] S210. Receive the motor start signal. After the motor control unit receives the start signal given by the switch circuit, it sends a start command to the position processing unit, and the position processing unit starts.

[0101] S220. Collect and obtain the acceleration values of the triaxial accelerometer according to the start signal. Specifically, first collect the static values of the triaxial accelerometer when the power tool starts according to the motor start signal, and after an interval of a preset time, collect the real-time acceleration values of the triaxial accelerometer. The difference between the real-time acceleration value and the static value is the acceleration value.

[0102] S230. Collect and obtain the angular velocity values of the triaxial gyroscope according to the start signal.

[0103] S240. When the acceleration value is greater than the third preset threshold, control the value of the fourth counter to increase by one; otherwise, clear the value of the fourth counter.

[0104] S250. When the angular velocity value is greater than the fourth preset threshold, control the value of the fifth counter to increase by one; otherwise, clear the value of the fifth counter.

[0105] S260. When the value of the fourth counter is greater than the fifth threshold or the value of the fifth counter is greater than the sixth threshold, send a stop command to the motor to control the motor to stop running; when the value of the fourth counter is not greater than the fifth threshold and the value of the fifth counter is not greater than the sixth threshold, then obtain the acceleration value and the angular velocity value again.

[0106] In steps S220 and S240, the triaxial accelerometer obtains the acceleration values on three coordinate axes, and after filtering processing respectively, compares them with the third preset threshold, and counts the filters corresponding to the three acceleration values respectively. The third preset threshold is the acceleration threshold; similarly, in steps S230 and S250, the triaxial gyroscope obtains the angular velocity values on three coordinate planes respectively, and after filtering processing respectively, compares them with the fourth preset threshold, and counts the filters corresponding to the three angular velocity values respectively. The fourth preset threshold is the angular velocity threshold.

[0107] In step S260, the motion of each axis independently performs threshold comparison. When the acceleration or angular velocity on any axis continuously exceeds the limit (that is, the counter value of any filter is greater than its corresponding preset threshold), the machine stops. The fifth threshold and the sixth threshold respectively correspond to the filtering times thresholds of the acceleration value and the angular velocity value, and they can be set to the same or different thresholds.

[0108] Please refer to Figures 11 to 12 , during the working process of the chainsaw, the sensor module continuously collects data. The position processing unit obtains the acceleration value and the angular velocity value through the triaxial accelerometer and the triaxial gyroscope respectively, and performs corresponding filtering processing on the data, and then compares it with the set threshold. Similar to the above control method, two-level judgments of the motion data threshold and the counter threshold are adopted. When the acceleration value or the angular velocity value in any direction is greater than the corresponding threshold and meets the filtering time, the position processing unit sends a stop command to the motor control unit. After receiving the stop command, the motor control unit controls the motor to stop. If the machine needs to be started again, the switch circuit signal needs to be released and the corresponding switch signal needs to be pressed again. Only then will the motor control unit drive the motor again and send a start signal to the position processing unit, and the position processing unit restarts to perform motion detection.

[0109] In summary, the control method and control system of the power tool of the present invention can effectively detect the motion and position changes of the power tool, realize effective intelligent braking control, and avoid risks caused by various uncertain and uncontrollable situations during the use of the power tool. By adopting the two-in-one sensor module of the accelerometer and the gyroscope, the accurate angular velocity value is obtained through fusion calculation. The actual angular velocity values in multiple directions are compared with the threshold for independent braking judgment, and the counter mechanism triggered by two-level conditions is adopted, which can adapt to complex motion scenarios, effectively avoid misjudgment, make the motion detection more accurate, the braking more sensitive, and improve the safety of using the power tool.

[0110] The above embodiments merely illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

[0111] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, parts, materials, articles, etc. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

[0112] Throughout the specification, reference to "an embodiment", "embodiment", or "specific embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, appearances of the phrases "in an embodiment", "in embodiments", or "in a specific embodiment" in various places throughout the specification are not necessarily referring to the same embodiment. Additionally, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be made in accordance with the teachings herein and will be considered part of the spirit and scope of the present invention.

[0113] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separated or more integrated manner, or even removed in some cases as they are inoperable or provided as they may be useful for a particular application.

[0114] Furthermore, unless otherwise explicitly specified, any marked arrows in the figures should be considered merely exemplary and not limiting. Additionally, unless otherwise indicated, the term "or" as used herein generally intends to mean "and / or". Where separation or combination capabilities are unclear due to the term being foreseen, a combination of components or steps will also be considered to have been specified.

[0115] As used in the description herein and throughout the claims below, unless otherwise indicated, "a", "an", and "the" include plural references. Also, as used in the description herein and throughout the claims below, unless otherwise indicated, the meaning of "in" includes "in" and "on".

[0116] The foregoing description of the embodiments shown in the present invention (including what is described in the abstract of the specification) is not intended to be exhaustive or to limit the present invention to the precise forms disclosed herein. While specific embodiments of the invention and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications will be apparent to and can be made by those skilled in the art within the spirit and scope of the present invention. As noted, these modifications can be made to the present invention in accordance with the foregoing description of the embodiments of the present invention, and these modifications will be within the spirit and scope of the present invention.

[0117] The systems and methods have been described generally herein to facilitate an understanding of the details of the present invention. In addition, various specific details have been given to provide a general understanding of embodiments of the present invention. However, one of ordinary skill in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of the specific details, or with other devices, systems, components, methods, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

[0118] Accordingly, while the present invention has been described herein with reference to its specific embodiments, modifications, various changes and substitutions are also within the foregoing disclosure, and it is to be understood that in some instances, some features of the present invention may be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Accordingly, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms and / or the specific embodiments disclosed as the best mode contemplated for carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the present invention will be determined only by the appended claims.

Claims

1. A control method for a power tool, characterized in that, including: Receiving a motor start signal; Collecting the acceleration values of a triaxial accelerometer according to the start signal and calculating to obtain corresponding angle values; Collecting and obtaining the angular velocity values of a triaxial gyroscope according to the start signal; Calculating and obtaining the actual angular velocity of the power tool movement according to the angle values and the angular velocity values; When the actual angular velocity is greater than a first preset threshold, controlling the counter value to be incremented by one; otherwise, clearing the counter value; When the counter value is greater than a second preset threshold, sending a stop command to the motor to control the motor to stop running; when the counter value is not greater than the second preset threshold, obtaining the angle values and the angular velocity values again.

2. The control method of the power tool according to claim 1, wherein The angle values include a first angle value, a second angle value, and a third angle value corresponding to the three axes on the triaxial accelerometer, and the angular velocity values include a first angular velocity value, a second angular velocity value, and a third angular velocity value corresponding to the three planes of the triaxial gyroscope. Among them, the steps of calculating and obtaining the actual angular velocity of the power tool movement according to the angle values and the angular velocity values include: Calculating and obtaining a first actual angular velocity according to the first angle value and the first angular velocity value; Calculating and obtaining a second actual angular velocity according to the second angle value and the second angular velocity value; Calculating and obtaining a third actual angular velocity according to the third angle value and the third angular velocity value.

3. The control method of the power tool according to claim 2, wherein, The steps of when the actual angular velocity is greater than the first preset threshold, controlling the counter value to be incremented by one; otherwise, clearing the counter value include: When the first actual angular velocity is greater than the first preset threshold, controlling the first counter value to be incremented by one; otherwise, clearing the first counter value; When the second actual angular velocity is greater than the first preset threshold, controlling the second counter value to be incremented by one; otherwise, clearing the second counter value; When the third actual angular velocity is greater than the first preset threshold, controlling the third counter value to be incremented by one; otherwise, clearing the third counter value.

4. The control method of the power tool according to claim 3, characterized in that, The steps of when the counter value is greater than the second preset threshold, sending a stop command to the motor to control the motor to stop running; when the counter value is not greater than the second preset threshold, obtaining the angle values and the angular velocity values again include: When any one of the first counter, the second counter, and the third counter has a value greater than the second preset threshold, sending a stop command to the motor to control the motor to stop running; when the values of the first counter, the second counter, and the third counter are all not greater than the second preset threshold, obtaining the angle values and the angular velocity values again.

5. A control method for a power tool, characterized in that, including: Receiving a motor start signal; Collecting and obtaining the acceleration values of a triaxial accelerometer according to the start signal; Collecting and obtaining the angular velocity values of a triaxial gyroscope according to the start signal; When the acceleration value is greater than a third preset threshold, controlling the fourth counter value to be incremented by one; otherwise, clearing the fourth counter value; When the angular velocity value is greater than a fourth preset threshold, controlling the fifth counter value to be incremented by one; otherwise, clearing the fifth counter value; When the value of the fourth counter is greater than the fifth threshold or the value of the fifth counter is greater than the sixth threshold, a stop command is sent to the motor to control the motor to stop running; when the value of the fourth counter is not greater than the fifth threshold and the value of the fifth counter is not greater than the sixth threshold, the acceleration value and the angular velocity value are acquired again.

6. The control method of the power tool according to claim 5, characterized in that, The step of acquiring the acceleration value of the triaxial accelerometer according to the start signal includes: Acquiring the static value of the triaxial accelerometer when the power tool starts according to the motor start signal; Acquiring the real-time acceleration value of the triaxial accelerometer after a preset time interval; Obtaining the difference between the real-time acceleration value and the static value as the acceleration value.

7. A control system for a power tool, characterized in that, Including: A data acquisition module, configured to receive a motor start signal, acquire the acceleration value of the triaxial accelerometer according to the start signal, calculate and obtain the corresponding angle value, and acquire the angular velocity value of the triaxial gyroscope according to the start signal; An angular velocity calculation module, configured to calculate and obtain the actual angular velocity of the power tool movement according to the angle value and the angular velocity value; A counting module, configured to compare the actual angular velocity with a first preset threshold. When the actual angular velocity is greater than the first preset threshold, the counter value is incremented by one; otherwise, the counter value is cleared; A control module, configured to send a stop command to the motor to control the motor to stop running when the counter value is greater than a second preset threshold.

8. An electric tool, characterized in that, Including: A power tool body, an accelerometer and a gyroscope disposed in the power tool body, and a processor disposed in the power tool; The processor is electrically connected to the accelerometer, the gyroscope, and the motor, and the processor is configured to execute the control method of the power tool according to any one of claims 1 to 6.

9. The electric tool according to claim 8, characterized in that, The power tool is any one of a chain saw and a one-handed saw.

10. The power tool according to claim 8, characterized in that, The accelerometer is a triaxial accelerometer, and the gyroscope is a triaxial gyroscope.

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