Smart power tool and control method thereof

Abstract

Embodiments of the present application disclose an intelligent electric power tool and a control method thereof. The intelligent electric power tool comprises: a motor; a power switch, which outputs a switch signal to control the power-on state of the motor; a detection unit, which is configured to detect the running parameters of the motor in real time; and a controller, which is electrically connected to at least the motor and the detection unit. The controller is configured to: when a power-off signal of the power switch is detected, acquire the running parameters of the motor; set the brake time of the intelligent electric power tool according to the running parameters, and control the motor to reduce the rotating speed within the brake time in response to the power-off signal. The intelligent electric power tool can solve the problems of the prior art, such as long brake time, slow start response speed and poor brake stability in the process of frequent on-off, so that the brake time of the intelligent electric power tool is automatically adjusted according to the real-time running parameters of the motor during the working process, the fast start is realized while the brake stability is ensured, the response speed of the intelligent electric power tool in the process of frequent on-off is improved, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of electric tool control, and particularly to an intelligent electric tool and a control method thereof. BACKGROUND

[0002] With the development of electric tools, intelligent control technology of electric tools is applied more and more widely. For example, a controller is used to drive a motor to realize the characteristics of fast start and smooth braking of an electric tool.

[0003] However, in the process of frequent on-off of the existing electric tool, if the rotating speed of the motor before starting is higher than a certain rotating speed A, i.e. the rotating speed when the last start is not completely stopped, the motor can be started immediately after the start signal is sent; if the rotating speed of the motor before starting is lower than a certain speed B, wherein B is less than A, the motor can be started immediately after the start signal is sent; however, if the rotating speed of the motor before starting is between A and B, the motor needs to be completely stopped based on a fixed time period after the start signal is sent, and then the motor can be restarted, and usually, in order to ensure that the motor can be completely stopped, the fixed time is relatively long, for example, it can be as long as 400 ms. Therefore, the response speed of the restart is affected. SUMMARY

[0004] The present application provides an intelligent electric tool and a control method thereof, so as to realize that during the working process of the intelligent electric tool, the braking time of the intelligent electric tool can be automatically adjusted according to the real-time running parameter of the motor, and the response speed of the intelligent electric tool during frequent on-off is improved.

[0005] In a first aspect, an embodiment of the present application provides an intelligent electric tool, comprising:

[0006] a motor;

[0007] a power switch, outputting a switch signal to control the power-on state of the motor;

[0008] a detection unit, configured to detect and obtain a running parameter of the motor in real time;

[0009] a controller, at least electrically connected with the motor and the detection unit;

[0010] the controller is configured to:

[0011] obtain the running parameter of the motor when detecting an off signal of the power switch;

[0012] set a braking time of the intelligent electric tool according to the running parameter, and control the motor to reduce the rotating speed within the braking time in response to the off signal.

[0013] In a second aspect, the embodiments of the present application further provide a control method of an intelligent electric power tool, which is executed by the intelligent electric power tool, and the intelligent electric power tool comprises a motor, a power switch, an output switch signal for controlling a power-on state of the motor, a detection unit for detecting an operating parameter of the motor in real time, and a controller electrically connected to at least the motor and the detection unit.

[0014] The control method comprises:

[0015] detecting the operating parameter of the motor when a power-off signal of the power switch is detected;

[0016] setting a brake time of the intelligent electric power tool according to the operating parameter, and controlling the motor to reduce a rotating speed within the brake time in response to the power-off signal.

[0017] The intelligent electric power tool comprises a motor, a power switch, an output switch signal for controlling a power-on state of the motor, a detection unit for detecting an operating parameter of the motor in real time, and a controller electrically connected to at least the motor and the detection unit. The controller is configured to: detect the operating parameter of the motor when a power-off signal of the power switch is detected; and set a brake time of the intelligent electric power tool according to the operating parameter, and control the motor to reduce a rotating speed within the brake time in response to the power-off signal. The intelligent electric power tool can solve the problems of the prior art, such as a long brake time, a slow response speed, and poor brake stability in a frequent on-off process, so that the intelligent electric power tool can automatically adjust the brake time according to the real-time operating parameter of the motor during the working process, and can realize a fast start while ensuring the brake stability, thereby improving the response speed of the intelligent electric power tool in the frequent on-off process and improving the working efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a circuit structure block diagram of an intelligent electric power tool in the embodiments of the present application;

[0019] Figure 2 is a brake control comparison effect diagram of the present application and the prior art in the embodiments of the present application;

[0020] Figure 3 is a circuit system block diagram of an intelligent electric power tool in the embodiments of the present application;

[0021] Figure 4 is a flowchart of a control method of an intelligent electric power tool in the embodiments of the present application. DETAILED DESCRIPTION

[0022] The application will be described in further detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be illustrative only and not limiting of the application. It should also be understood that, in the description, relative terms are used to generally describe the components of the application and their relationships to one another. These terms are not intended to limit the scope or application of the application.

[0023] Figure 1 A circuit structure block diagram of an intelligent electric tool is provided for the embodiments of the application. Referring to Figure 1 , the intelligent electric tool comprises: a motor 101; a power switch 102, outputting a switch signal to control the power-on state of the motor 101; a detection unit 103, configured to detect the running parameters of the motor 101 in real time; a controller 104, electrically connected to at least the motor 101 and the detection unit 103; the controller 104 is configured to: acquire the running parameters of the motor 101 when detecting the power-off signal of the power switch 102; set the brake time of the intelligent electric tool according to the running parameters, and control the motor 101 to reduce the rotating speed within the brake time in response to the power-off signal.

[0024] The motor 101 can be a three-phase motor, the power switch 102 can be a relay switch, and the controller 104 can be a single-chip microcomputer, an electronic control unit (ECU), etc. The controller 104 can also be electrically connected to the power switch 102, and the power-on signal or power-off signal output by the power switch 102 can also be output to the controller 104. Thus, the controller 104 can detect in real time whether the power switch 102 outputs a power-off signal or a power-on signal. When detecting that the power switch 102 outputs a power-off signal, the running parameters of the motor 101 before power-off are acquired, the brake time of the intelligent electric tool is set according to the running parameters, and the motor 101 is controlled to reduce the rotating speed within the brake time in response to the power-off signal. The so-called reduction of the rotating speed can be to control the motor rotating speed to reduce to a certain range, or to control the motor rotating speed to reduce to zero, i.e., to control the motor to stop rotating.

[0025] Typically, during frequent power tool switching, if the motor is at a high speed (e.g., 36,000 RPM) before starting, it can start immediately upon receiving a start signal. If the motor is at a lower speed (e.g., 18,000 RPM) before starting, it can also start immediately upon receiving a start signal. However, if the motor speed is between the higher and lower speeds before starting, it requires a longer braking time (e.g., typically around 400 milliseconds) after receiving a start signal before it can start. This is because it is difficult to find a suitable rotor position at this speed, requiring complete braking before starting. The intelligent power tool provided by this embodiment can: detect in real-time whether the power switch is issuing a switching signal; when a power switch shutdown signal is detected, obtain the current motor operating parameters; set the braking time of the intelligent power tool based on the real-time motor operating parameters; and respond to the shutdown signal during the braking time to control the motor to reduce its speed or directly reduce it to zero. Therefore, it can be seen that the controller can adaptively adjust the braking time of the intelligent power tool according to the real-time operating parameters of the motor. This avoids the problems caused by setting a fixed braking time in the conventional way, which cannot be adaptively adjusted. Such problems include braking time that is too short, affecting braking smoothness, and braking time that is too long, affecting the response speed of frequent start-up and shutdown. This allows the intelligent power tool to achieve rapid start-up while ensuring braking smoothness, improving the response speed of the intelligent power tool when frequently starting and stopping, and improving work efficiency.

[0026] It should be noted that the intelligent power tools provided in the embodiments of this invention can be handheld power tools, garden power tools, vehicle-mounted power tools, etc. These power tools include, but are not limited to, the following: screwdrivers, drills, wrenches, angle grinders, and other power tools requiring speed adjustment; sanders and other power tools that may be used for grinding workpieces; reciprocating saws, circular saws, jigsaws, and other power tools that may be used for cutting workpieces; and electric hammers and other power tools that may be used for impact applications. These power tools may also be garden tools, such as pruning machines and chainsaws; furthermore, these power tools may also be used for other purposes, such as mixers.

[0027] The technical scheme of the embodiment provides an intelligent electric tool, which comprises: a motor; a power switch, which outputs a switch signal to control the power-on state of the motor; a detection unit, which is configured to detect the running parameter of the motor in real time; and a controller, which is electrically connected to the motor and the detection unit; the controller is configured to: acquire the running parameter of the motor when detecting a power-off signal of the power switch; set the brake time of the intelligent electric tool according to the running parameter; and control the motor to reduce the rotating speed within the brake time in response to the power-off signal. The intelligent electric tool can solve the problems of the prior art, such as long brake time, slow start response speed and poor brake stability in the process of frequent on-off, so that the intelligent electric tool can automatically adjust the brake time according to the real-time running parameter of the motor during the working process, realize fast start while ensuring the brake stability, improve the response speed of the intelligent electric tool in the process of frequent on-off, and improve the working efficiency.

[0028] The intelligent electric tool provided in the embodiment can execute the control method of the intelligent electric tool provided in any of the embodiments, and has the corresponding function modules and beneficial effects.

[0029] Optionally, the running parameter comprises the rotating speed, the current or the voltage.

[0030] The running parameter of the motor 101 can be the rotating speed of the motor, the working current of the motor or the working voltage of the motor. Correspondingly, the detection unit 103 can be a rotating speed detection unit, a current detection unit or a voltage detection unit. The rotating speed detection unit can be a Hall sensor or an encoder, which is configured to detect the rotating speed of the motor 101 in real time. The current detection unit can be a current transformer, which is configured to detect the current value of the motor 101 in real time. The voltage detection unit can be a voltage transformer, which is configured to detect the voltage value of the motor 101 in real time.

[0031] Specifically, when the detection unit 103 is a rotation speed detection unit, the rotation speed detection unit detects the rotation speed of the motor in real time and sends it to the controller 104, and when the controller 104 detects that the power switch 102 sends a shutdown signal, the rotation speed value of the motor 101 sent by the rotation speed detection unit at this time is obtained, and the brake time of the intelligent power tool is set according to the rotation speed value of the motor 101 at this time, and the motor 101 is controlled to reduce the rotation speed or directly reduce to zero within the brake time in response to the shutdown signal. When the detection unit 103 is a current detection unit, the current detection unit detects the current value of the motor in real time and sends it to the controller 104, and when the controller 104 detects that the power switch 102 sends a shutdown signal, the current value of the motor 101 sent by the current detection unit at this time is obtained, and the brake time of the intelligent power tool is set according to the current value of the motor 101 at this time, and the motor 101 is controlled to reduce the rotation speed or directly reduce to zero within the brake time in response to the shutdown signal. When the detection unit 103 is a voltage detection unit, the voltage detection unit detects the voltage value of the motor in real time and sends it to the controller 104, and when the controller 104 detects that the power switch 102 sends a shutdown signal, the voltage value of the motor 101 sent by the voltage detection unit at this time is obtained, and the brake time of the intelligent power tool is set according to the voltage value of the motor 101 at this time, and the motor 101 is controlled to reduce the rotation speed or directly reduce to zero within the brake time in response to the shutdown signal.

[0032] It should be noted that in the embodiments of the present application, only the operating parameters of the motor such as rotation speed, current and voltage are taken as examples for description, and the operating parameters of the motor can also be power and the like, which can be set according to actual conditions and are not limited specifically herein.

[0033] Optionally, the brake time includes a preset brake time.

[0034] The controller is configured to control the motor to reduce the rotation speed in response to the shutdown signal after the preset brake time.

[0035] The preset brake time is the free running time of the motor after the power switch 102 sends the shutdown signal, and the preset brake time is a time period for determining that the power switch 102 is completely released (that is, there is a buffer time from the release to the complete release of the power switch 102). The preset brake time can be 20 milliseconds.

[0036] As an implementation manner, Figure 2 is a comparison effect diagram of the brake control of the present application and prior art provided by the embodiments of the present application, which is exemplary and takes the operating parameter of the motor as rotation speed for example, and is described with reference to Figure 2L1 (dashed line) is the change curve of the motor speed in the switching process in the prior art, and L2 (solid line) is the change curve of the motor speed in the switching process in the embodiment of the application. Wherein, the period of 0-T1 is the normal operation period of the motor; the period of T1-T2 is the preset brake time, which is used to determine a time period in which the power switch 102 is completely released; T3 is the brake stop time of the intelligent electric tool in the embodiment of the application, and T4 is the restart time of the intelligent electric tool after the brake stop for a certain time in the embodiment of the application; T5 is the brake stop time of the electric tool in the prior art, and T6 is the restart time of the electric tool after the brake stop for a certain time in the prior art; wherein, the time period of T3-T4 is the same as the time period of T5-T6. At the moment of T1, the power switch 102 sends a shutdown signal to the controller 104 and shuts down, and after the controller 104 receives the shutdown signal, the brake time is set according to the speed of the motor 101 at this time (when the shutdown signal is sent) detected by the detection unit 103, and the motor is controlled to reduce the speed or directly reduce to zero after the preset brake time. At the same time, during the period of T1-T2, the motor 101 freely slides, the motor speed slightly reduces, and after experiencing the preset brake time (i.e. the period of T1-T2), the brake instruction sent by the controller 104 is executed.

[0037] Specifically, referring to the curve L1, under the control of the prior art, when the motor 101 runs 36000 revolutions, the power switch 102 is disconnected, the motor 101 freely slides for 20 milliseconds of filtering time, and then executes the brake instruction, and after 140 milliseconds, the motor 101 speed reduces to zero, i.e. the brake time is 140 milliseconds. Even if the power switch 102 is pressed within 140 milliseconds, it is necessary to wait until the brake ends at 140 milliseconds to determine whether the power switch is closed and restart the motor. And when the motor 101 runs 18000 revolutions, the power switch 102 is disconnected, and it can be started after 140 milliseconds.

[0038] Under the control of the intelligent electric power tool provided by the embodiment of the present application, for example, referring to the curve L2, when the motor 101 runs 18000 revolutions, the power switch 102 is disconnected, the motor 101 freely slides for 20 milliseconds of filtering time, and then the braking instruction is executed, and after 70 milliseconds, the motor 101 speed is reduced to zero, that is, the braking time is 70 milliseconds. Compared with the prior art, it can be judged that the braking time of 70 milliseconds can be stopped stably, and then it can be judged that the power switch 102 is closed and the motor is started, so that the entire time length can be shortened by 70 milliseconds from the braking stop to the restart of the motor. It can be seen that the fast start is realized while ensuring the braking stability, the response speed of the intelligent electric power tool is improved, and the work efficiency is improved. It should be noted that the embodiment is only an example, different speeds correspond to different braking times, and the longest can be shortened by 110 milliseconds, and the specific braking time can be set according to the actual motor operating parameters.

[0039] Figure 3 is a circuit system block diagram of an intelligent electric power tool provided by the embodiment of the present application. Optionally, referring to Figure 3 The intelligent electric power tool further comprises:

[0040] The capacitor element C0 is connected in parallel with the motor 101.

[0041] The switch element S0 is connected in series with a resistor element R0 and then connected in parallel with the motor 101.

[0042] The controller 104 is configured to:

[0043] After detecting the shutdown signal for a preset time period, the switch element S0 is turned on.

[0044] In the prior art, generally, after the power switch is disconnected, the capacitor element is discharged, and after the power switch is closed again within a predetermined time, the capacitor element is recharged, and the instantaneous charging current is too large, which is easy to cause the power switch to spark and stick failure. Therefore, in the embodiment of the present application, the capacitor element C0 is connected in parallel with the motor 101, the switch element S0 is connected in series with a resistor element R0 and then connected in parallel with the motor 101, and the controller 104 is arranged to control the switch element S0 to be turned on after detecting the shutdown signal for a preset time period. Thus, when the power switch 102 is disconnected and the intelligent electric power tool brakes, the switch element S0 is turned on after a preset time, and even if the power switch 102 is closed again, that is, the continuous start after shutdown, the capacitor element C0 does not need to be charged within the preset time, so that the capacitor element C0 has not been discharged after the previous charging, so that the power switch 102 will not spark. The preset time can be about 60 seconds.

[0045] Optionally, the switch element S0 is a transistor.

[0046] wherein the reference Figure 3 The control terminal of the switch element S0 is electrically connected with the controller 104, and the controller 104 outputs a switch signal to control the conduction or turn-off of the switch element S0. The switch element S0 can be a semiconductor power device (such as FET, BJT, IGBT, etc.), or any other type of solid-state switch, such as an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc.

[0047] Optionally, referring to Figure 3 The intelligent electric power tool further comprises a power supply 10, a power conversion circuit 20 and a driving circuit 30. The power energy output by the power supply 10 is output by the power conversion circuit 20 and then provided to the motor 101 and the controller 104, and the power conversion circuit 20 can be a power conversion chip; the driving circuit 30 is used to drive the motor to rotate. In order to make the motor rotate, the driving circuit 30 has multiple driving states, and in one driving state, the stator winding of the motor will generate a magnetic field, and the controller 104 outputs a corresponding PWM control signal to the switch element in the driving circuit 30 according to the rotor position or back electromotive force of the motor, so as to make the driving circuit 30 switch the driving state, so that the stator winding generates a changing magnetic field to drive the rotor to rotate, thereby realizing the rotation or commutation or speed adjustment of the motor. It should be noted that any circuit and control mode capable of driving the rotation or commutation or speed adjustment of the motor can be used in the present disclosure, and the circuit structure of the driving circuit 30 and the control of the controller 104 to the driving circuit 30 are not limited.

[0048] Figure 4 is a flowchart of a control method of an intelligent electric power tool provided by an embodiment of the present application. The embodiment can be applied to the implementation process of the control method of the intelligent electric power tool. The method can be executed by the intelligent electric power tool provided by the embodiment of the present application. The intelligent electric power tool comprises a motor, a power switch, an output switch signal for controlling the power-on state of the motor, a detection unit for real-time detection of the running parameters of the motor, and a controller electrically connected with the motor and the detection unit. Referring to Figure 4 , specifically comprising the following steps:

[0049] Step 110, obtaining the running parameters of the motor when the power-off signal of the power switch is detected;

[0050] The intelligent electric power tool comprises a motor, a controller, a detection unit and a power switch, and specifically, the power switch sends a power-on signal or a power-off signal to the controller, and the controller responds to the power-on signal or the power-off signal after receiving the power-on signal or the power-off signal. Specifically, the controller obtains the running parameters of the motor detected by the detection unit after receiving the power-off signal of the power switch.

[0051] Step 120: Set the braking time of the intelligent power tool according to the operating parameters, and control the motor to reduce the speed in response to the shutdown signal during the braking time.

[0052] Specifically, the detection unit monitors the motor's operating parameters in real time and sends them to the controller. The controller monitors whether the power switch is sending a switching signal. When it detects a power-off signal, it obtains the motor's operating parameters before braking, sets the braking time of the smart power tool based on the motor's real-time operating parameters, and responds to the power-off signal within the braking time to control the motor to reduce its speed or reduce it to zero. Therefore, the controller can adaptively adjust the braking time of the smart power tool according to the motor's real-time operating parameters. This avoids the problems associated with conventional fixed braking times that cannot be adaptively adjusted, such as braking time that is too short affecting braking smoothness or braking time that is too long affecting the response speed of frequent power on / off cycles. This allows the smart power tool to achieve rapid start-up while ensuring braking smoothness, improving the response speed of frequent power on / off cycles and increasing work efficiency.

[0053] The technical solution of this embodiment provides a control method for an intelligent power tool. This control method is executed by the intelligent power tool, which includes: a motor; a power switch that outputs a switch signal to control the power-on state of the motor; a detection unit for real-time detection of the motor's operating parameters; and a controller electrically connected to at least the motor and the detection unit. The controller is configured to: acquire the motor's operating parameters when a power switch shutdown signal is detected; set the braking time of the intelligent power tool according to the operating parameters; and control the motor to reduce its speed in response to the shutdown signal during the braking time. This intelligent power tool solves the problems of excessively long braking time, slow start-up response, and poor braking smoothness in existing technologies during frequent power-on and power-off cycles. It enables the intelligent power tool to automatically adjust the braking time according to the real-time operating parameters of the motor during operation, achieving rapid start-up while ensuring braking smoothness, improving the response speed of the intelligent power tool during frequent power-on and power-off cycles, and increasing work efficiency.

[0054] Optionally, operating parameters may include rotational speed, current, or voltage.

[0055] Optionally, the braking time includes a preset braking time;

[0056] Responding to a shutdown signal during the braking time to control the motor to reduce its speed includes: responding to a shutdown signal after a preset braking time to control the motor to reduce its speed.

[0057] Optionally, the intelligent power tool also includes: a capacitor element connected in parallel with the motor; and a switching element connected in series with a resistor element and then in parallel with the motor.

[0058] The control method further includes controlling the switch element to be conductive after a preset time period from detecting the shutdown signal.

[0059] Optionally, the switch element is a transistor.

[0060] It should be noted that the above only describes the preferred embodiments of the present application and the principles of the applied technology. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A smart power tool that allows for frequent on / off switching, comprising: Electric motor; A power switch outputs a switch signal to control the power-on state of the motor; The detection unit is used to detect and obtain the operating parameters of the motor in real time; The controller is electrically connected to at least the motor and the detection unit; The controller is configured to: When the power switch is detected to be off, the operating parameters of the motor are acquired; The braking time of the intelligent power tool is set according to the operating parameters, and the motor is controlled to reduce its speed in response to the shutdown signal during the braking time. During the braking time, the motor is not allowed to be restarted; Also includes: The capacitor element is connected in parallel with the motor; A switching element, connected in series with a resistive element, is then connected in parallel with the motor. The controller is configured to: After a preset time period following the detection of the shutdown signal, the switching element is controlled to turn on.

2. The intelligent power tool according to claim 1, characterized in that, The operating parameters include rotational speed, current, or voltage.

3. The intelligent power tool according to claim 1, characterized in that, The braking time includes a preset braking time; The controller is configured to respond to the shutdown signal after the preset braking time and control the motor to reduce its speed.

4. The intelligent power tool according to claim 1, characterized in that, The switching element is a transistor.

5. A control method for an intelligent power tool, characterized in that, Performed by any one of claims 1-4, the intelligent power tool includes a motor, a power switch, and an output switch signal to control the power-on state of the motor; The detection unit is used to detect and obtain the operating parameters of the motor in real time; The controller is electrically connected to at least the motor and the detection unit; The control method includes: When the power switch is detected to be off, the operating parameters of the motor are acquired; The braking time of the intelligent power tool is set according to the operating parameters, and the motor is controlled to reduce its speed in response to the shutdown signal during the braking time.

6. The control method for intelligent power tools according to claim 5, characterized in that, The operating parameters include rotational speed, current, or voltage.

7. The control method for intelligent power tools according to claim 5, characterized in that, The braking time includes a preset braking time; The step of responding to the shutdown signal and controlling the motor to reduce its speed within the braking time includes: responding to the shutdown signal and controlling the motor to reduce its speed after the preset braking time.

8. The control method for intelligent power tools according to claim 5, characterized in that, The intelligent power tool further includes: a capacitor element connected in parallel with the motor; and a switching element connected in series with a resistor element and then in parallel with the motor. The control method further includes: controlling the switching element to conduct after a preset time period following the detection of the shutdown signal.

9. The control method for intelligent power tools according to claim 8, characterized in that, The switching element is a transistor.

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