Multifunctional electric pruning shear control method and device

Abstract

The invention provides a multifunctional electric pruning shear control method and device. The pruning shear is powered on and started, and a tool edge of the pruning shear is controlled to retract to a tool retracting limiting point; after the trigger is shifted, the motion amount of the trigger is detected, and the motion amount of the trigger is processed to obtain the target stroke of the motor; pID processing is carried out on the target stroke of the motor to obtain a PWM duty ratio of the driving motor; and driving the motor to operate according to the PWM duty ratio, and calibrating the actual stroke of the motor when the knife edge operates to the calibration position. According to the pruning shears, enough shearing force can be maintained, and the precision and smoothness of knife edge and stroke control are improved. Moreover, three-ring control of a position ring, a speed ring and a current ring is adopted to replace braking with speed reduction, so that the pause feeling during shutdown disappears, and the user experience is improved.

Description

Technical Field

[0001] The invention relates to the technical field of pruning shears control, and in particular to a multifunctional electric pruning shears control method and device. Background Art

[0002] Electric scissors are handheld electric tools that use an electric motor as a power source to drive the scissor heads for cutting operations. Currently, the scissor heads of most electric scissors can only be opened and closed at a fixed angle, and cannot be changed according to the size of the object to be cut, which is inconvenient to use.

[0003] The patent application with the publication number CN115362841A and the invention name "A method for controlling the cutting opening of an electric shearing tool" uses the inductive principle to sense the distance between the trigger key and the inductive sensor to control the cutting opening of the electric shearing tool. The control of the electric shears uses the basic principle of stroke control, and the accuracy and smoothness of the control need to be improved.

[0004] The patent application with publication number CN116058188A and invention name "A method for calibrating the blade position, electric tool and computer-readable medium" discloses a scheme for calibrating the blade position. The blade position of the pruning shears is calibrated by calculating the number of rotations through the change in the motor's back electromotive force. This scheme is only applicable to the case of no load and it is difficult to ensure the stability of the blade position control under heavy load conditions.

[0005] Therefore, the control of electric trimmers currently needs to be improved. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a multifunctional electric pruning shears control method and device, so as to solve the problem of poor control effect of the electric pruning shears blade in the prior art.

[0007] To achieve the above-mentioned and other related purposes, the present invention provides a multifunctional electric pruning shears control method, which comprises at least the following steps:

[0008] The pruning shears are powered on and the blade is controlled to retract to the retraction limit point;

[0009] After the trigger is pulled, the trigger movement amount is detected, and the trigger movement amount is processed to obtain the motor target stroke;

[0010] Performing PID processing on the motor target stroke to obtain a PWM duty cycle of the drive motor;

[0011] The motor is driven to run according to the PWM duty cycle, and the actual stroke of the motor is calibrated when the blade runs to the calibration position.

[0012] Optionally, when the actual stroke of the motor is inconsistent with the target stroke, the motor rotates to pursue the target stroke and enters PID closed-loop control.

[0013] Optionally, in the PID closed-loop control, the position loop, the speed loop and the current loop are processed in sequence to obtain the PWM duty cycle of the drive motor.

[0014] Optionally, the step of processing the motor target stroke to obtain a PWM duty cycle of the driving motor includes:

[0015] 1) obtaining a stroke difference according to the motor target stroke and the motor actual stroke, and calculating a target speed according to the stroke difference;

[0016] 2) obtaining a speed difference according to the target speed and the actual speed, and calculating a target current according to the speed difference;

[0017] 3) According to the current difference between the target current and the actual current, the PWM duty cycle of the driving motor is calculated according to the current difference.

[0018] Optionally, when the motor driving board controls the phase change rotation of the motor, each phase change is counted once, based on the set initial stroke point, and the actual stroke of the motor is obtained by adding or subtracting the stroke according to whether the motor rotates forward or reverse.

[0019] Optionally, the calibration position includes a closed calibration point and an open calibration point.

[0020] Optionally, it also includes controlling the working mode of the pruning shears after pulling the trigger; the working mode includes a stroke controllable mode and a single full-stroke mode: the pruning shears are placed in different working modes by processing the trigger value area.

[0021] Optionally, when the trigger value area is processed into two extreme values, the pruning shears are in a single full-stroke mode; when the trigger value area is processed into a continuous value, the pruning shears are in a stroke controllable mode.

[0022] Optionally, the trigger value area is a trigger Hall value or a motor target stroke.

[0023] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a multifunctional electric pruning shears control device, comprising a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the above-mentioned multifunctional electric pruning shears control method are implemented.

[0024] As described above, the multifunctional electric pruning shears control method and device of the present invention have the following beneficial effects:

[0025] The present invention provides a multifunctional electric pruning shear control method and device. When the pruning shears are powered on, the blade is controlled to retract to the retraction limit point; after the trigger is pulled, the trigger movement is detected, and the trigger movement is processed to obtain the motor target stroke; the motor target stroke is processed by PID to obtain the PWM duty cycle of the drive motor; the motor is driven to run according to the PWM duty cycle, and the actual motor stroke is calibrated when the blade runs to the calibration position. The present invention obtains the PWM duty cycle of the drive motor through the processing of the PID position loop, speed loop and current loop, wherein the position loop makes the blade run with the trigger, the speed loop makes the blade run speed follow the trigger run speed, and the current loop realizes shear force control, maintains sufficient shear force of the pruning shears, and improves the accuracy and smoothness of the blade and stroke control. In addition, the three-loop control of the position loop + speed loop + current loop is adopted to realize deceleration instead of braking, so that the sense of frustration when stopping disappears, and the user experience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a schematic diagram of the blade travel control logic of the pruning shears in the present invention.

[0027] Figure 2 Shown is a schematic flow chart of the control method of the multifunctional pruning shears of the present invention.

[0028] Figure 3 It is a schematic diagram showing the distribution of key points of the blade operation in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] See also Figure 1-Figure 3 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0031] The position of the pruning shears blade is obtained by calculating the motor stroke, so the blade stroke can be matched with the motor stroke. However, under some working conditions, the motor stroke and the blade stroke will be inconsistent, which will eventually lead to over-cutting, that is, the blade will be separated from the motor gear. Special working conditions, such as when the machine is turned on, the motor stroke and the blade position are generally not matched; or under heavy load, the motor stroke and the blade position are also prone to errors.

[0032] In order to avoid the above situation, it is necessary to place sensors as calibration points in the closing and opening directions to assist in calibrating the motor stroke so that it matches the blade position; at the same time, sensors are also required as tool retraction limit points for the corresponding tool stop and stroke when the machine is turned on.

[0033] Therefore, the present invention proposes a multifunctional electric pruning shear control solution, which is specifically introduced in detail through the following embodiments:

[0034] Embodiment 1

[0035] The positioning sensor of the trigger of the pruning shears of the present invention is a linear Hall sensor, that is, a magnet is installed on the trigger. The linear Hall sensor outputs different voltages according to the magnitude of the magnetic field, and the operating state of the trigger can be judged, thereby controlling the blade travel of the pruning shears. Figure 1 As shown, the blade stroke changes according to the output value of the trigger Hall, that is, the blade follows the trigger to achieve controllable stroke.

[0036] The present invention proposes a multifunctional electric pruning shear control method, such as Figure 2 As shown, the method comprises at least the following steps:

[0037] S1, the pruning shears are powered on and the blade is controlled to retract to the retraction limit point;

[0038] In a specific embodiment of the present invention, the blade may appear at any position when the machine is turned on. Therefore, the blade needs to be controlled to retract first, and the motor controls the blade to retract to the retraction limit point to stop immediately, and the blade and motor stroke are initialized synchronously.

[0039] Therefore, the pruning shears of the present invention are powered on and turned on, and then the blade of the pruning shears is controlled to retract at a uniform speed to a retraction limit point.

[0040] S2, detecting the amount of movement of the trigger after the trigger is pulled, and processing the amount of movement of the trigger to obtain a target stroke of the motor;

[0041] The pruning shears have a motor that drives the blade to run, so the stroke of the blade can be equivalent to the stroke of the motor; and the stroke of the blade is controlled by the stroke of the trigger, that is, the blade stroke is proportional to the trigger stroke; then, the present invention realizes the operation control of the blade / blade by converting the trigger stroke into the motor stroke, so as to perform subsequent detection and processing.

[0042] In a specific embodiment of the present invention, after the pruning shears are initialized, the trigger is pulled, the trigger operation is detected, and the trigger movement amount is converted and normalized into the motor target stroke. The trigger movement amount refers to the stroke amount of pulling the trigger.

[0043] S3, performing PID processing on the motor target stroke to obtain a PWM duty cycle of the driving motor;

[0044] In a specific embodiment of the present invention, the normalized motor target stroke and the motor actual stroke are processed to obtain the target speed, and then the target current is obtained based on the target speed and the actual speed; finally, the PWM duty cycle of the drive motor is obtained based on the target current and the actual speed, that is, the position loop, speed loop and current loop are processed to obtain the PWM duty cycle of the drive motor.

[0045] In a specific embodiment of the present invention, the process of processing the motor target stroke to obtain the PWM duty cycle of the driving motor includes:

[0046] 1) obtaining a stroke difference according to the motor target stroke and the motor actual stroke, and calculating a target speed according to the stroke difference;

[0047] In the present invention, the actual stroke of the motor is obtained by counting once each time the motor driver board controls the motor to change phase and rotate, based on the set initial stroke point, and adding or subtracting the stroke according to whether the motor rotates forward or reverse to obtain the actual stroke of the motor.

[0048] In the present invention, when the actual stroke of the motor is inconsistent with the target stroke, the motor rotates to pursue the target stroke, thereby entering into PID closed-loop control.

[0049] More specifically, the difference between the actual stroke of the motor and the target stroke (ie, the stroke difference) is substituted into the PID (position loop) calculation formula to obtain the target speed of the motor.

[0050] 2) obtaining a speed difference according to the target speed and the actual speed, and calculating a target current according to the speed difference;

[0051] In a specific embodiment of the present invention, the difference between the actual speed of the motor and the target speed of the motor (ie, the speed difference) is brought into a PID (speed loop) calculation formula to obtain the target current of the motor.

[0052] 3) According to the current difference between the target current and the actual current, the PWM duty cycle of the driving motor is calculated according to the current difference.

[0053] In a specific embodiment of the present invention, the difference between the actual current and the target current of the motor (ie, the current difference) is brought into a PID (current loop) calculation formula to obtain an output PWM waveform to drive the motor to operate.

[0054] In a specific embodiment of the present invention, the operation state of the blade is determined according to the difference; the operation state includes the direction of movement, speed change and duty cycle adjustment change. Among them, the sign of the stroke difference determines the direction of movement (closed operation or open operation), the sign of the speed difference determines the speed change (acceleration or deceleration), and the sign of the current difference determines the duty cycle adjustment change (increase duty cycle or decrease duty cycle). In addition: the absolute value of the stroke difference will also affect acceleration / deceleration, and acceleration or deceleration will affect the increase or decrease of current, and finally affect the increase or decrease of duty cycle.

[0055] The present invention adopts the control mode of position loop + speed loop + current loop to achieve the following functions: the position loop makes the blade follow the trigger, the speed loop makes the blade follow the trigger, and the current loop controls the shearing force to maintain sufficient shearing force of the pruning shears.

[0056] In addition, using the brakes during the operation of the pruning shears' motor will cause the motor to feel jerky when it stops, affecting the feel of use. The present invention uses a three-loop control of position loop + speed loop + current loop to achieve deceleration instead of braking, which eliminates the jerky feeling when stopping and improves the user experience.

[0057] S4, driving the motor to run according to the PWM duty cycle, and calibrating the actual stroke of the motor when the blade runs to a calibration position. The calibration position includes a closed calibration point and an open calibration point.

[0058] In a specific embodiment of the present invention, when the blade is running in a closed position, if a closed calibration point is encountered, the actual stroke of the motor is calibrated; when the blade is running in an open position, if an open calibration point is encountered, the actual stroke of the motor is calibrated. The calibration is to calibrate the number of motor turns before the calibration position. The present invention uses the interaction between the number of motor turns and the Hall element to ensure that the blade position remains stable under heavy load.

[0059] Specifically, Figure 3 As shown in the figure, during the closing process, when the knife edge passes the closing calibration point (before the closing point), the calibration motor stroke is consistent with the knife edge position / stroke, so that the position of the knife edge when it reaches the closing point is stable. During the opening process, when the knife edge passes the opening calibration point (before the retracting limit point), the calibration motor stroke is consistent with the knife edge position / stroke, so that the position of the knife edge when it reaches the retracting limit point is stable.

[0060] It should be noted here that: because it is a non-sensing square wave control, it is inevitable that the motor stroke will be calculated inaccurately under heavy load. When shearing, the friction and pressure are the largest when the blade cuts to the middle of the branch diameter, so the load is also the largest, and the motor stroke will be deviated at this time. However, when the blade cuts further downward, the branch is gradually cut off, the friction and pressure of the branch will also decrease, and the load will also decrease at this time, and the impact on the blade stroke will also decrease or even have no effect. Therefore, a Hall point is added before the closed position. When the blade passes through the Hall point, the software calibrates the blade stroke value to ensure accurate stopping. Similarly, if the blade is retracted when the blade cuts half of the branch, the load is also large at this time, which also affects the motor stroke. However, when the blade gradually withdraws from the branch, the load decreases and the impact decreases. At this time, adding a Hall calibration point before the retraction limit point can calibrate the blade / motor stroke by software to make the retraction position accurate.

[0061] S5, further comprising controlling the working mode of the pruning shears after pulling the trigger; the working mode includes a stroke controllable mode and a single full stroke mode;

[0062] Among them, the stroke-controllable mode: the motor target stroke is a continuous quantity, which allows the blade to follow the trigger; the pruning shears in the stroke-controllable mode can be used for grafting openings, fine pruning, etc.

[0063] Among them, in single full-stroke mode: the motor target stroke has only two values: opening stroke and closing stroke; the pruning shears in single full-stroke mode cut the entire stroke at the highest speed, which can improve the cutting speed and efficiency.

[0064] In a specific embodiment of the present invention, two working modes of the pruning shears are realized by processing the trigger value area into a continuous value or a two-extreme value, wherein the trigger value area is a trigger Hall value or a motor target stroke.

[0065] In a specific embodiment of the present invention, if the pruning shears are in a single full-stroke mode, the trigger value area needs to be processed into two poles. A specific implementation method is: when the trigger value area is a trigger Hall value, if the trigger Hall value is greater than A, the trigger is considered to be "1", and the target stroke of the motor is fully closed throughout the entire stroke; if the trigger Hall value is less than B, the trigger is considered to be "0", and the target stroke of the motor is fully opened at the starting position, where A>B, in order to achieve a hysteresis anti-shake function.

[0066] In a specific embodiment of the present invention, if the pruning shears are in a single full-stroke mode, the trigger value area needs to be processed into two poles. Another specific implementation method is: when the trigger value area is the motor target stroke, since the trigger Hall value and the motor target stroke have a certain proportional relationship, it can be processed by the motor target stroke; that is, if the motor target stroke is greater than M, the motor target stroke is full stroke, that is, fully closed; if the motor target stroke is less than N, the motor target stroke is the starting position, that is, fully open, where M>N, in order to achieve a hysteresis anti-shake function.

[0067] Therefore, when the trigger value range is processed into two extreme values, the pruning shears are in a single full-stroke mode; when the trigger value range is processed into a continuous value, the pruning shears are in a stroke-controllable mode; that is, a pair of pruning shears has two working modes, thereby increasing the application market of the pruning shears.

[0068] In a specific embodiment of the present invention, based on the blade stroke / motor stroke obtained, the opening size of the blade can be controlled, so that the pruning shears can be controlled to enable different blades when processing branches of different thicknesses.

[0069] If the branches are relatively thin, you can use the small mouth mode to reduce power consumption while meeting your needs, increase battery life, or reduce the battery size to reduce the weight of the entire device.

[0070] If the branches are relatively thick, you can turn on the large-mouth mode to meet the needs of large-diameter cutting.

[0071] It should be noted here that the control of the knife-edge mode is modified when the motor is stationary, and can be selected by double-clicking or long pressing the button or trigger.

[0072] Embodiment 2

[0073] To achieve the above-mentioned purpose and other related purposes, the present invention provides a multifunctional electric pruning shears control device, comprising a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the multifunctional electric pruning shears control method are implemented.

[0074] The processor in the present invention can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc., and can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0075] Among them, the detailed process of the steps of the multifunctional electric pruning shears control method has been described in detail in the method embodiment and will not be repeated here.

[0076] In summary, a multifunctional electric pruning shear control method and device are provided. When the pruning shears are powered on, the blade is controlled to retract to the retraction limit point; after the trigger is pulled, the trigger movement is detected, and the trigger movement is processed to obtain the motor target stroke; the motor target stroke is PID processed to obtain the PWM duty cycle of the drive motor; the motor is driven to run according to the PWM duty cycle, and the actual motor stroke is calibrated when the blade runs to the calibration position. The present invention improves the accuracy and smoothness of the blade and stroke control through the three-loop control of position loop + speed loop + current loop. In addition, the three-loop control of position loop + speed loop + current loop is used to achieve deceleration instead of braking, so that the sense of frustration when stopping disappears and the user experience is improved. In addition, the two working modes and optional opening sizes can meet different application scenarios. Therefore, the present invention effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A multifunctional electric pruning shears control method, It is characterized in that At least the following steps are included: The pruning shears are powered on and the blade is controlled to retract to the retraction limit point; After the trigger is pulled, the trigger movement amount is detected, and the trigger movement amount is processed to obtain the motor target stroke; Performing PID processing on the motor target stroke to obtain a PWM duty cycle of the drive motor; The motor is driven to run according to the PWM duty cycle, and the actual stroke of the motor is calibrated when the blade runs to the calibration position.

2. The multifunctional electric pruning shears control method according to claim 1, It is characterized in that When the actual motor stroke is inconsistent with the target stroke, the motor rotates to pursue the motor target stroke and enters PID closed-loop control.

3. The control method of the multifunctional electric pruning shears according to claim 1, It is characterized in that In the PID closed-loop control, the position loop, speed loop and current loop are processed in sequence to obtain the PWM duty cycle of the drive motor.

4. The control method of the multifunctional electric pruning shears according to claim 1, It is characterized in that The step of processing the motor target stroke to obtain the PWM duty cycle of the driving motor includes: 1) obtaining a stroke difference according to the motor target stroke and the motor actual stroke, and calculating a target speed according to the stroke difference; 2) obtaining a speed difference according to the target speed and the actual speed, and calculating a target current according to the speed difference; 3) According to the current difference between the target current and the actual current, the PWM duty cycle of the driving motor is calculated according to the current difference.

5. The control method of the multifunctional electric pruning shears according to claim 4, It is characterized in that When the motor driving board controls the motor's phase change rotation, each phase change is counted once. Based on the set initial stroke point, the actual stroke of the motor is obtained by adding or subtracting the stroke according to whether the motor is rotating forward or reverse.

6. The control method of the multifunctional electric pruning shears according to claim 1, It is characterized in that The calibration position includes a closed calibration point and an open calibration point.

7. The control method of the multifunctional electric pruning shears according to claim 1, It is characterized in that It also includes controlling the working mode of the pruning shears after pulling the trigger; the working mode includes a stroke controllable mode and a single full-stroke mode: the pruning shears are placed in different working modes by processing the trigger value area.

8. The control method of the multifunctional electric pruning shears according to claim 7, It is characterized in that When the trigger value zone is processed into two extreme values, the pruning shears are in a single full-stroke mode; when the trigger value zone is processed into a continuous value, the pruning shears are in a stroke controllable mode.

9. The control method of the multifunctional electric pruning shears according to claim 8, It is characterized in that The trigger value area is the trigger Hall value or the motor target stroke.

10. A multifunctional electric pruning shears control device, It is characterized in that The invention comprises a memory, a processor and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the control method of the multifunctional electric pruning shears according to any one of claims 1 to 9 are implemented.

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