A control method and system for grinding equipment based on brushless motor

Abstract

The present invention relates to the field of grinding equipment control technology, and specifically to a grinding equipment control method and system based on a brushless motor. The method includes: obtaining a target speed; obtaining an actual speed, calculating a first difference between the target speed and the actual speed; if it is less than a second preset difference and greater than a first preset difference, performing current compensation on the grinding equipment, including the steps of: compensating the current of the grinding equipment to obtain a first compensation speed; judging whether the second difference between the first compensation speed and the target speed is greater than the first preset difference; if it is greater than the first preset difference, judging whether it is less than a sixth preset difference; if it is greater than the sixth preset difference, generating a first shift signal; if it is less than the sixth preset difference, continuing to compensate the current in batches. The present invention incorporates current compensation, speed feedback, and reciprocating acceleration cycle adjustment into a unified control framework to form a closed-loop adjustment with high scene adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding equipment control, and in particular to a grinding equipment control method and system based on a brushless motor. Background Art

[0002] There are many potential safety hazards in the use of grinding equipment. At present, some control methods for grinding equipment are provided in the prior art.

[0003] For example, patent application CN113199348A discloses a grinding equipment control method, system, and grinding equipment. The method includes obtaining target information input by a user; if the target information includes the target position information of the end effector during the grinding process, then determining the real-time force information of the end effector, and determining the speed information of the grinding motor based on the real-time force information; based on the target position information and the speed information, controlling the grinding motor to drive the end effector to grind the grinding object in a constant position grinding mode. Since the real-time force information of the end effector is allowed to change during the grinding process, smooth constant position grinding can be achieved. Moreover, it can meet the force changes of the end effector when the corrugation of the groove cutting surface is corrected, and realize the correction of the corrugation of the groove cutting surface. There is no need for manual post-repair, which saves labor costs. It can also realize functions such as residual grinding and weld smoothing. It can be used in the process of welding and other process grinding of medium and large workpieces to improve the grinding efficiency.

[0004] Although this method provides an effective approach for solving specific problems (such as groove correction), it is not suitable for fine grinding scenarios of small grinding equipment.

[0005] Therefore, there is an urgent need for a method that can ensure that even ordinary users who are not familiar with grinding operations can use small grinding equipment safely and efficiently. Summary of the Invention

[0006] The purpose of the present invention is to provide a method and system for controlling grinding equipment based on a brushless motor, which partially solves or alleviates the above-mentioned shortcomings in the prior art and can ensure that even ordinary users who are not familiar with grinding operations can use small grinding equipment safely and efficiently.

[0007] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0008] A first aspect of the present invention is to provide a method for controlling a grinding device based on a brushless motor, comprising:

[0009] Obtaining a first target speed of the grinding equipment;

[0010] Acquire an actual speed, and calculate a first difference between the first target speed and the actual speed;

[0011] If the first difference is smaller than the second preset difference and larger than the first preset difference, current compensation is performed on the grinding device, and the current compensation includes the steps of:

[0012] Compensating the current of the grinding device to obtain a first compensation speed;

[0013] determining whether a second difference between the first compensation speed and a second target speed at the current moment is greater than the first preset difference;

[0014] If the second difference is greater than the first preset difference, determining whether the second difference is less than a sixth preset difference;

[0015] If it is greater than the sixth preset difference, generating a first gear shift signal;

[0016] If it is less than the sixth preset difference, then continue to compensate the current in batches; wherein each compensation current does not exceed the first current compensation value;

[0017] The sixth preset difference is greater than the first preset difference, and both the sixth preset difference and the first preset difference are predefined by a user.

[0018] In some embodiments, before generating the first shift signal, the method further includes the following steps:

[0019] monitoring the temperature of the grinding device, and limiting the current of the grinding device if the temperature of the grinding device is continuously greater than a preset temperature threshold;

[0020] If the body temperature is continuously lower than the preset temperature threshold, current limiting is stopped.

[0021] In some embodiments, including:

[0022] Controlling the grinding device according to a reciprocating grinding cycle, wherein one reciprocating grinding cycle includes: a gear acceleration cycle T and a gear deceleration cycle T;

[0023] Obtaining the gear acceleration period T during the first time period;

[0024] Obtaining a plurality of actual speeds and a fourth target speed corresponding to the gear acceleration period T;

[0025] A plurality of speed ratios between the actual speed and the fourth target speed within the gear acceleration period T are calculated, and if the number of the speed ratios greater than a first ratio does not exceed a preset number, the gear acceleration period T is shortened.

[0026] In some embodiments, the steps further include:

[0027] If the number of the speed ratios greater than the first ratio exceeds a preset number, the gear acceleration period T is lengthened.

[0028] In some embodiments, the steps further include:

[0029] Acquire multiple actual speeds and multiple third target speeds in a second period;

[0030] calculating third differences between the plurality of actual speeds and the plurality of third target speeds;

[0031] When the third difference is less than the fifth preset difference, the gear acceleration period T is lengthened.

[0032] In some embodiments, the steps further include:

[0033] determining whether the first difference between the first target speed and the actual speed is less than a fourth preset difference;

[0034] If so, generating a first prompt signal;

[0035] If the duration of the first prompt signal exceeds a preset threshold time, a first control signal is generated, and the first control signal is used to control the main power switch of the grinding device.

[0036] In some embodiments, the steps further include:

[0037] If the first difference is greater than the second preset difference and less than the third preset difference, a polishing posture adjustment prompt is generated;

[0038] If the first difference is greater than the third preset difference, it is determined whether the first target speed exceeds the grinding speed threshold of the grinding device; if so, the device is forced to shut down.

[0039] The present invention also provides a brushless motor-based grinding equipment control system, the system comprising:

[0040] A speed acquisition module is used to acquire a first target speed of the grinding device; acquire an actual speed, and calculate a first difference between the target speed and the actual speed;

[0041] A current compensation module is configured to perform current compensation on the grinding device when the first difference is less than the second preset difference and greater than the first preset difference, wherein the current compensation includes:

[0042] a compensation unit, configured to compensate the current of the grinding device to obtain a first compensation speed;

[0043] a first determining unit, configured to determine whether a second difference between the first compensation speed and a second target speed at a current moment is greater than the first preset difference;

[0044] a second judging unit, configured to judge whether the second difference is less than a sixth preset difference when the second difference is greater than the first preset difference;

[0045] The first execution unit is configured to generate a first shift signal when the current is greater than the sixth preset difference; and to continue compensating the current in stages when the current is less than the sixth preset difference; wherein each compensation current does not exceed the first current compensation value; wherein the sixth preset difference is greater than the first preset difference, and both the sixth preset difference and the first preset difference are predefined by a user.

[0046] In some embodiments, further comprising:

[0047] The temperature monitoring unit is used to monitor the body temperature of the grinding device. If the body temperature is continuously greater than a preset temperature threshold, the current of the grinding device is limited; if the body temperature is continuously less than the preset temperature threshold, the current limiting is stopped.

[0048] In some embodiments, further comprising:

[0049] A reciprocating grinding cycle unit, configured to control the grinding device according to a reciprocating grinding cycle, wherein one reciprocating grinding cycle includes a gear acceleration cycle T and a gear deceleration cycle T;

[0050] an acceleration cycle acquiring unit, configured to acquire the gear acceleration cycle T in the first time period; and acquire a plurality of actual speeds and a fourth target speed corresponding to the gear acceleration cycle T;

[0051] The gear cycle adjustment unit is used to calculate multiple speed ratios between the actual speed and the target speed within the gear acceleration cycle T, and shorten the gear acceleration cycle T if the number of the speed ratios greater than the first ratio does not exceed a preset number.

[0052] Beneficial technical effects:

[0053] This invention integrates the speed difference judgment and compensation current linkage mechanism with the gear acceleration cycle adjustment strategy to integrate current compensation, speed feedback, and gear switching into a unified control framework, forming a closed-loop regulation with high adaptability to various scenarios. This is especially true for household handheld grinding equipment, as shown in the following aspects:

[0054] 1) This invention implements a segmented compensation process for speed differences generated during the grinding process, triggering current compensation within an adaptively adjustable range to directly perform closed-loop corrections based on the speed difference. If the speed difference becomes unadjustable, progressive current compensation is abandoned, and a prompt to adjust the grinding posture or terminate the grinding process is generated directly. This ensures grinding efficiency while better adapting to the varying skill levels of various operators, effectively avoiding potential safety hazards caused by operator unfamiliarity or distraction.

[0055] 2) The present invention also provides a speed feedback mechanism based on segmented compensation. By dynamically adjusting the gear acceleration period T, the reciprocating grinding period is further adaptively adjusted. The hardness of the material being ground is distinguished and the corresponding grinding gear acceleration period is designed based on the speed feedback after segmented compensation. This can meet the requirements of the fineness of grinding in home grinding scenarios while, to a certain extent, avoiding the operator's inability to select the appropriate grinding speed due to unfamiliarity with the grinding process, thereby helping to adaptively improve the grinding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the various elements or parts are not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work.

[0057] Figure 1 A schematic flow chart of a method for controlling a grinding device based on a brushless motor provided in an embodiment of the present application;

[0058] Figure 2 A schematic diagram of a control system for a grinding device based on a brushless motor provided in an embodiment of the present application;

[0059] Figure 3 A schematic structural diagram of a brushless motor-based grinding device provided in an embodiment of the present application;

[0060] Figure 4 Another flowchart of a method for controlling a grinding device based on a brushless motor provided in an embodiment of the present application;

[0061] Figure 5 Another flow chart of a method for controlling a grinding device based on a brushless motor provided in an embodiment of the present application;

[0062] Figure 6A schematic diagram of the working range of a brushless motor-based grinding equipment control method provided in an embodiment of the present application;

[0063] Summary of reference numerals: 01, brushless motor; 02, grinding head. DETAILED DESCRIPTION

[0064] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] Herein, suffixes such as "module," "component," or "unit" used to represent elements are only used to facilitate description of the present invention and have no specific meaning. Therefore, "module," "component," or "unit" may be used interchangeably.

[0066] As used herein, terms such as "upper," "lower," "inner," "outer," "front," "back," "one end," and "the other end" indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] As used herein, unless otherwise expressly specified or limited, the terms "installed," "provided with," and "connected" should be understood broadly. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention on a case-by-case basis.

[0068] As used herein, "and / or" includes any and all combinations of one or more of the associated listed items.

[0069] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0070] As used in this specification, the term "about" typically means + / - 5% of the stated value, more typically + / - 4% of the stated value, more typically + / - 3% of the stated value, more typically + / - 2% of the stated value, even more typically + / - 1% of the stated value, and even more typically + / - 0.5% of the stated value.

[0071] In this specification, certain embodiments may be disclosed in a format that is within a range. It should be understood that this description of "within a range" is merely for convenience and brevity and should not be interpreted as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within this range. For example, the description of a range of 1-6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. Regardless of the breadth of the range, the above rules apply.

[0072] Definition of noun:

[0073] A brushless motor (also known as a brushless DC motor, BLDC) is an electric motor that does not use traditional mechanical carbon brushes and a commutator for current commutation. Instead, an electronic controller (such as a circuit board) precisely switches the direction of the current in the coils, driving the rotation of the internal permanent magnet rotor. Compared to brushed motors, brushless motors offer significant advantages such as higher efficiency, longer life, lower noise, more precise speed control, and reduced maintenance requirements. Consequently, they are widely used in applications requiring high performance and reliability, such as drones, power tools, fans, electric vehicles, hard drives, robotics, and household appliances.

[0074] Field-oriented control (FOC) is a technique for precisely controlling AC motors (particularly permanent magnet synchronous motors (PMSMs) and brushless DC motors (BLDCs). Its core concept is to virtually convert the actual three-phase AC current in the motor's stator windings into a DC current in the coordinate system of the rotating rotor magnetic field through complex mathematical transformations (such as the Clarke and Park transforms). One component (the direct-axis current, Id) is dedicated to generating or weakening the magnetic field, while the other (the quadrature-axis current, Iq) directly and linearly controls the motor's torque output. By continuously tracking the rotor pole position (typically using an encoder) and performing this coordinate transformation and current regulation in real time, FOC ensures that the motor magnetic field (the stator magnetic field vector) always maintains a precise angular relationship (typically 90 degrees) with the rotor magnetic field, maximizing torque efficiency and achieving extremely smooth, quiet, and responsive speed and torque control. This makes FOC particularly suitable for high-performance applications such as electric vehicles, industrial robots, and precision servo systems.

[0075] A Hall effect controller is an electronic control device that uses Hall effect sensors to detect the real-time position of the permanent magnet rotor in a brushless motor. By reading signals from the Hall effect sensors mounted on the motor's stator, it accurately determines the angle of the rotor's magnetic poles. Based on this information, it logically switches the direction and timing of the current supplied to the stator windings, thereby driving the motor's continuous and smooth rotation. A Hall effect controller is a key component for basic commutation (determining when the coils are energized) in brushless motors. Its relatively simple structure and low cost make it widely used in applications where reliable operation is essential but control accuracy is not critical, such as electric bicycles, fans, hard drive motors, and some power tools.

[0076] The present invention provides a control method based on a closed-loop brushless motor, which can be applied to various types of electric equipment, such as grinding equipment (such as Figure 3 The control method of the brushless motor will be exemplarily described below using a grinding device as an example. It is understandable that in other embodiments, the grinding device can be replaced by an electric screwdriver.

[0077] Example 1:

[0078] See also Figure 1 As shown, the present invention provides a method for controlling a grinding device based on a brushless motor, comprising the steps of:

[0079] Obtaining a first target speed of a grinding device (i.e., an electric device);

[0080] Acquire an actual speed, and calculate a first difference between the first target speed and the actual speed;

[0081] If the first difference is smaller than the second preset difference and larger than the first preset difference, current compensation is performed on the grinding device, and the current compensation includes the steps of:

[0082] Compensating the current of the grinding device to obtain a first compensation speed;

[0083] determining whether a second difference between the first compensation speed and a second target speed at the current moment is greater than the first preset difference;

[0084] If the second difference is greater than the first preset difference, determining whether the second difference is less than a sixth preset difference;

[0085] If it is greater than the sixth preset difference, generating a first gear shift signal;

[0086] If it is less than the sixth preset difference, the current compensation continues in batches; wherein, each compensation current does not exceed the first current compensation value; wherein, the sixth preset difference is greater than the first preset difference, and the sixth preset difference and the first preset difference are both pre-defined by the user.

[0087] Among them, see Figure 3 The brushless motor-based grinding equipment used in the present invention at least includes a brushless motor 01 and a grinding head 02.

[0088] In some embodiments, the grinding device is a grinding pen with an overall pen-like structure. The brushless motor is placed vertically directly inside the body of the device. The output shaft of the brushless motor is coaxial with the grinding head, cutter head, and screwdriver head (the coaxiality deviation between the two shafts is approximately 0-0.5mm). The motor is directly driven, and there is no reduction mechanism between the motor and the grinding head. The grinding head is designed to be quickly interchangeable and can be locked using various methods (including but not limited to splines, set screws, threaded interlocks, etc.). Different grinding heads, cutter heads, screwdriver heads, etc. (wherein cutter heads should include but not be limited to round, semi-circular, oval, serrated, needle-shaped, grinding wheels, etc.) can be quickly replaced.

[0089] This embodiment provides a segmented compensation mechanism for manual sanding. This mechanism improves both the performance of manual sanding and the safety of household manual operations. It provides a categorized compensation strategy based on current compensation feedback, particularly mitigating or reducing operational risks caused by improper operator posture or distraction.

[0090] This segmented compensation mechanism is particularly suitable for ordinary DIY enthusiasts. It should be noted that ordinary DIY enthusiasts may not have professional experience in operating industrial equipment, so there are problems such as incorrect use of grinding equipment or poor grinding results. The segmented compensation mechanism proposed in this invention can solve these problems in a targeted manner. Specifically:

[0091] Different solutions are set for different numerical intervals in which the first difference between the target speed and the actual speed lies. When the first difference is within an acceptable range (i.e., less than the second preset difference and greater than the first preset difference), current compensation can be performed on the grinding equipment; when the first difference is large (i.e., greater than the second preset difference and less than the third preset difference), the problem is most likely not caused by the grinding equipment parameters (i.e., grinding speed). At this time, the user's grinding posture problem is considered, and a posture adjustment prompt is initiated to the user; when the first difference exceeds the acceptable range (i.e., greater than the third preset difference), it is determined whether the target speed of grinding exceeds the grinding speed threshold to prevent the operator from losing control of the grinding equipment due to distraction or unfamiliarity with the grinding process, thereby damaging the grinding equipment and even causing injury to the operator.

[0092] It should be understood that the purpose of setting the first preset difference, the second preset difference, and the third preset difference is to classify the reasons behind the speed difference. For example, when the first difference is greater than the first preset difference and less than the second preset difference, it means that the difference between the actual speed of the grinding device and the target speed is within the adaptive control range; when the difference between the actual speed of the grinding device and the target speed is greater than the second preset difference and less than the third preset difference, it means that the grinding speed of the grinding device has a large gap with the preset gear speed. In order to avoid the operator's erroneous operation due to lack of expertise or distraction, the corresponding grinding posture adjustment prompt is provided. In this way, the speed adjustment is avoided through current compensation or current limiting in a one-size-fits-all manner, and the operator's own factors in the grinding scene are also included in the grinding device control method, further enhancing the scene adaptability of the present invention. It should be noted that the target speed mentioned in the present invention can be a preset or user-selected gear speed.

[0093] The inventors have noticed that the grinding equipment may not be able to reach the preset grinding speed due to grinding resistance, so it is necessary to perform current compensation on the grinding equipment so that the actual grinding speed of the grinding equipment is as close to the target speed as possible. In this embodiment, for ease of understanding, the target speed can refer to the target grinding speed of each gear, or it can be the target speed of current compensation or current limiting, or it can be the target speed after adjusting the reciprocating grinding cycle. Based on the different grinding states at different times, the target speed is adaptively adjusted by compensating / limiting the current, which is conducive to improving the scenario adaptability of the present invention.

[0094] In some embodiments, the actual speed refers to the actual grinding speed during the grinding process. The gear acceleration period is the acceleration period T for the grinding speed of the grinding device to reach the preset grinding speed (i.e., target speed) of each grinding gear (e.g., high speed, medium speed, low speed).

[0095] In some embodiments, the compensation speed is the actual grinding speed of the grinding device after the compensation current is applied.

[0096] The present invention proposes a gradual current compensation scheme for grinding equipment (i.e., incremental current compensation of the grinding equipment, for example, by 1% each time) to ensure the safety and controllability of the grinding process and effectively improve the adaptability of the grinding equipment under abnormal working conditions. The scheme includes the following steps:

[0097] In some embodiments, if the second difference between the first compensation speed and the second target speed is greater than the first preset difference, two situations may occur: first, a stall or a potential stall has occurred, in which case the speed gear should be increased to overcome the stall or potential stall; second, insufficient compensation current is required, and further compensation is required. By determining whether the second difference is less than a sixth preset difference, the "insufficient compensation current" and "potential stall" conditions can be distinguished, significantly reducing the risk of motor burnout due to stalling and extending the life of the equipment.

[0098] Specifically, a determination is made as to whether the second difference is less than a sixth preset difference. If so, this indicates that the grinding device's speed is increasing with the increase in compensation current, and current compensation can be continued. If the second difference is greater than the sixth preset difference, this indicates that even with current compensation, the speed has not significantly changed. In this case, a stall or stalling situation is likely. Continuing current compensation or grinding could cause the grinding device to overheat or even damage the device. Therefore, a first shift signal is generated, discontinuing current compensation within the target speed range of the original gear and instead updating the target speed to a higher gear, thereby avoiding the stall or stalling situation. If the difference is adjustable, current compensation continues until the target speed is approached. If the difference is not adjustable, progressive compensation (i.e., incremental current compensation) is abandoned, and the device is directly switched to a higher speed gear, thus breaking through speed bottlenecks and adapting to complex operating conditions (such as sudden changes in workpiece surface hardness). This solution, through speed difference determination and compensation current linkage mechanisms, combined with a gear shifting strategy, integrates current compensation and speed feedback into a unified control framework, forming a closed-loop regulation system and improving the adaptability of the grinding device control method to various scenarios.

[0099] In some embodiments, current compensation is continued in stages within the target speed range; wherein each compensation current does not exceed the first current compensation value. The purpose of this stepwise current compensation is to gradually increase the current, preventing excessive current compensation at once that could overheat the grinding equipment, damage the equipment, or even injure the operator. The compensation current is limited by a threshold value, effectively preventing current overload, thereby balancing response speed and stability, reducing ineffective compensation energy consumption, and improving the energy efficiency of the grinding process.

[0100] In some embodiments, before generating the first shift signal, the method further includes:

[0101] monitoring the temperature of the grinding device, and limiting the current of the grinding device if the temperature of the grinding device is continuously greater than a preset temperature threshold;

[0102] In some embodiments, if the body temperature is continuously lower than a preset temperature threshold, current limiting is stopped.

[0103] In some embodiments, current limiting refers to limiting the current in the circuit so that the current does not exceed a preset value. The purpose of current limiting is to avoid excessive temperatures during grinding, which may cause the grinding equipment to overheat (including motor temperature, main control circuit temperature, battery temperature, etc.). On the one hand, it prevents the operator from accidentally dropping the device due to excessive temperature, and on the other hand, it can also protect the grinding equipment.

[0104] In some embodiments, see Figure 4 , also includes:

[0105] Controlling the grinding device according to a reciprocating grinding cycle, wherein one reciprocating grinding cycle includes: a gear acceleration cycle T and a gear deceleration cycle T;

[0106] Obtaining the gear acceleration period T during the first time period;

[0107] Obtaining a plurality of actual speeds and a fourth target speed corresponding to the gear acceleration period T;

[0108] A plurality of speed ratios between the actual speed and the fourth target speed within the gear acceleration period T are calculated, and if the number of the speed ratios greater than a first ratio does not exceed a preset number, the gear acceleration period T is shortened.

[0109] Preferably, the present invention also proposes a reciprocating grinding method. Compared with the traditional electric grinding method, the present invention adopts a brushless motor and FOC control technology to enable the grinding equipment to realize a variety of grinding methods, such as reciprocating grinding. Reciprocating grinding can be regarded as a bionic grinding method during the working process of the grinding equipment, that is, it can be close to the effect of manually grinding the workpiece with sandpaper reciprocatingly. Since improper control of unidirectional high-speed rotation grinding can easily damage the workpiece, reciprocating grinding can ensure that the grinding process is more controllable. Therefore, reciprocating grinding can more accurately control the grinding position and speed (especially suitable for processing details such as sprues and part edges), and the grinding effect will be smoother than unidirectional grinding.

[0110] In some embodiments, when the grinding device is performing reciprocating grinding, its grinding head will undergo a process of forward acceleration, grinding at a constant speed at a certain speed, and then decelerating in the reverse direction. This process will be repeated in each reciprocating grinding motion. In the forward acceleration stage, the rotation speed of the grinding head gradually increases from zero. When the rotation speed reaches or is infinitely close to the preset grinding speed of the gear under the action of resistance, it will maintain this maximum speed and grind at a constant speed for a period of time. Then, in the reverse deceleration stage, the rotation speed of the grinding head gradually decreases to zero, and then forward acceleration, constant speed grinding, and reverse deceleration are performed in the other grinding direction, and this is repeated. Therefore, when the grinding device is performing reciprocating grinding, the curve of the rotation speed of the grinding device over time presents a periodic morphological feature similar to a sine wave.

[0111] In some embodiments, due to the influence of grinding resistance, if the number of speed ratios greater than the first ratio does not exceed a preset number, it usually indicates that the material being ground is a hard material. At this time, the gear acceleration cycle T of the grinding equipment can be shortened, so as to approach the target speed within a shorter gear acceleration cycle.

[0112] In some embodiments, the gear acceleration period T may be shortened or lengthened by accurately compensating or limiting the current through a brushless motor and a FOC control method.

[0113] In some embodiments, it further includes:

[0114] If the number of the speed ratios greater than the first ratio exceeds a preset number, the gear acceleration period T is lengthened.

[0115] In this embodiment, the present invention also provides a speed feedback mechanism based on segmented compensation. According to the speed change characteristics of the grinding equipment during the reciprocating operation, the gear acceleration cycle T is dynamically adjusted to further achieve adaptive adjustment of the reciprocating grinding cycle, which is conducive to improving the grinding quality and efficiency of manual grinding. Specifically, the dynamic adjustment of the gear acceleration cycle T is reflected in: according to the speed feedback after segmented compensation, the hardness of the material being ground is distinguished and the corresponding grinding gear acceleration cycle is designed. In this way, while meeting the fineness requirements of the grinding in the home grinding scene, it can avoid the operator's inability to select the appropriate grinding speed due to unfamiliarity with the grinding process to a certain extent, thereby helping to adaptively improve the grinding efficiency.

[0116] Furthermore, for hard materials, the gear acceleration cycle T is shortened, that is, the period during which the actual grinding speed approaches the maximum speed is shortened, so that grinding can be completed in a shorter time, and the adaptability of grinding parameters to hard materials (such as metal surfaces) is improved; for soft materials, the gear acceleration cycle T is lengthened, so that the actual grinding speed approaches the maximum speed more slowly, avoiding overheating that causes plastic melting and affects the grinding quality or efficiency.

[0117] In some embodiments, the present invention can reduce the temperature of the machine body to a certain extent by lengthening the gear acceleration period T, thereby alleviating or reducing the risk of the grinding material melting due to overheating and hindering the grinding process.

[0118] In some embodiments, see Figure 5 , the method further comprises the steps of:

[0119] Acquire multiple actual speeds and multiple third target speeds in a second period;

[0120] calculating third differences between the plurality of actual speeds and a plurality of third target speeds;

[0121] When the difference is less than a fifth preset difference, the gear acceleration period T is lengthened.

[0122] The fifth preset difference is smaller than the first preset difference.

[0123] That is to say, in this embodiment, after the gear acceleration cycle T is reduced and adjusted, the effect of the adjustment can be continuously observed. When it is found that the actual speed in the next time period is too high, it is preferred to extend the gear acceleration cycle again to avoid improper adjustment of the gear acceleration cycle.

[0124] This adjustment of the gear acceleration cycle can, to a certain extent, avoid misadjustment for soft materials. For example, the applicant noted that during the grinding process of soft materials, the material may rapidly heat up and melt due to reciprocating grinding. This melt may increase the resistance to the grinding head, prompting the grinding equipment to significantly compensate for the speed (e.g., reduce the gear acceleration cycle) to overcome this resistance. However, once the melt is eliminated by grinding (i.e., the resistance is significantly reduced), an excessively short gear acceleration cycle may result in excessively fast grinding speeds that are unsuitable for grinding soft materials. For example, this may cause recurring problems such as high temperature overheating and material melting.

[0125] To this end, the present invention utilizes continuous adjustment and monitoring during the first and second time periods to avoid misadjustments to the gear acceleration cycle caused by melt. Notably, the present invention provides a dual adjustment mechanism based on speed compensation and acceleration cycle adjustment. This dual adjustment mechanism, based on feedback from single-point speed compensation and cross-analysis and verification of acceleration cycles, can provide a safe and versatile set of grinding equipment for household grinding. Specifically, this dual adjustment mechanism of cross-analysis and verification can, on the one hand, provide matching grinding parameters (such as speed and cycle) for different types of grinding surfaces, while also preventing over-adjustment from negatively impacting grinding safety or effectiveness.

[0126] In summary, for materials of different hardness and softness, the present invention provides a dynamic adjustment mechanism for adjusting the reciprocating grinding cycle based on speed adjustment feedback.

[0127] According to the difference between the actual speed and the target speed, the present invention can accurately infer whether the working state of the grinding equipment is abnormal, and further dynamically and adaptively respond to the misjudgment of material hardness according to the working state of the grinding equipment, which is conducive to achieving more detailed grinding scenes by adjusting the gear acceleration cycle T, thereby improving the grinding efficiency and safety of the grinding equipment.

[0128] It can also be understood from another perspective: when the hardness of the material being polished is low but is mistakenly judged to be high, it will usually lead to excessive polishing effect and even the grinding equipment idling phenomenon. The present invention can judge whether idling phenomenon occurs or is about to occur based on the difference between the actual speed and the target speed (that is, if the difference between the actual speed and the target speed is less than the fifth preset difference, it is judged that the grinding equipment is idling or is about to occur idling trend). At this time, the gear acceleration cycle T is adjusted, which can make the grinding equipment make the actual grinding speed approach the maximum speed more slowly, thereby getting rid of the idling trend.

[0129] In some embodiments, the present invention can further enhance the adaptability of a grinding device to various operating conditions by adjusting the gear acceleration period of the grinding device. By lengthening the gear acceleration period T, both efficiency and safety of grinding can be balanced, to some extent avoiding the situation where the difference between the actual speed and the target speed is less than the fifth preset difference, thus preventing the grinding device from being engulfed by molten material, resulting in a sudden drop in friction and a phenomenon similar to idling.

[0130] In some embodiments, including:

[0131] Determine whether a first difference between the first target speed and the actual speed is less than a fourth preset difference; if so, generate a first prompt signal.

[0132] In some embodiments, it further includes:

[0133] If the duration of the first prompt signal exceeds a preset threshold time, a first control signal is generated, and the first control signal is used to control the main power switch of the grinding device.

[0134] In some embodiments, due to improper operation by the operator or too little grinding friction, the grinding equipment may idle or tend to idle. Therefore, when there is a suspected idling trend, that is, when the first difference between the target speed and the actual speed is less than the fourth preset difference, the present invention sends a first prompt signal to the operator to avoid damage to the equipment caused by idling.

[0135] In some embodiments, it also includes that if the duration of the first prompt signal exceeds a preset threshold time, it means that the idling trend or idling situation has continued for a period of time. At this time, a first control signal is issued to avoid equipment damage and safety hazards caused by long-term idling of the grinding equipment.

[0136] In some embodiments, it further includes:

[0137] If the first difference is greater than the second preset difference and less than the third preset difference, a polishing posture adjustment prompt is generated.

[0138] In some embodiments, it further includes:

[0139] If the first difference is greater than a third preset difference, it is determined whether the target speed exceeds a grinding speed threshold of the grinding device; if so, the device is forced to shut down.

[0140] It should be understood that when the first difference is greater than the third preset difference, it means that the difference between the actual speed and the target speed is very large, which means that the material being polished is not suitable for this polishing equipment (for example, the material being polished is very hard). Even if the speed gear is increased, the polishing requirements cannot be met. Therefore, the operator needs to switch to other polishing equipment (for example, other polishing equipment with higher or lower rated power) to meet his polishing needs.

[0141] See Figure 6 For ease of understanding, the “difference” and “preset difference” in the present invention will be uniformly described below as examples to explain the operating rules of the above technical solution:

[0142] 1. The first difference mentioned in this article refers to the difference between the initial first target speed and the actual speed; the second difference mentioned in this article refers to the difference between the second target speed after current compensation and the actual speed (i.e., the first compensated speed); the third difference mentioned in this article refers to the difference between the third target speed after adjusting the acceleration period and the actual speed;

[0143] In this document, each preset difference is used to define a range of differences. For example, the first through fourth preset differences are defined to determine whether to activate the current compensation mechanism. The fifth and sixth preset differences are defined to determine whether and how to further adjust the operating parameters of the current compensation mechanism (e.g., the gear acceleration cycle) after the current compensation mechanism is activated.

[0144] 2. For example, the first preset difference, the second preset difference, and the third preset difference mentioned in this article are used to distinguish the control schemes of the grinding equipment according to the difference range of the first difference between the first target speed and the actual speed; specifically:

[0145] If the first difference is smaller than the second preset difference and larger than the first preset difference, it belongs to the current compensation range. Within this range, the first difference can be reduced by current compensation, thereby improving the grinding efficiency;

[0146] If the first difference is less than the third preset difference and greater than the second preset difference, a prompt is given to adjust the posture to avoid low polishing efficiency due to user distraction;

[0147] If the first difference is greater than the third preset difference, the handheld grinding device is forced to shut down to prevent the material being ground from being unsuitable for the household handheld grinding device.

[0148] 3. The fourth preset difference mentioned in this article is to avoid idling tendency. If the first difference is smaller than the fourth preset difference, it means that the actual speed is very close to the first target speed and idling tendency is likely to occur;

[0149] In some embodiments, when the first difference is greater than or equal to a fourth preset difference, the user may decide whether to start current compensation.

[0150] Alternatively, in other embodiments, the fourth preset difference may not be set (or, the fourth preset difference = the first preset difference), that is, when it is less than the first preset difference, a first prompt signal may be generated to prompt the user to determine whether there is a risk of idling.

[0151] 4. The fifth and sixth preset differences mentioned in this article are used to further determine the working condition of the grinding equipment after adjusting the acceleration cycle or compensation current. Specifically:

[0152] If the third difference is less than the fifth preset difference, it means that the compensation is too much or the material being polished is soft. In this case, the cycle should be lengthened to avoid idling.

[0153] If the second difference is greater than the sixth preset difference, it means that the compensation current is ineffective, and a gear shift is recommended;

[0154] If the second difference is smaller than the sixth preset difference, it indicates that the compensation is effective, and the compensation is continued in batches.

[0155] For example, the relative sizes of the first preset difference to the sixth preset difference are Figure 6 In some embodiments, the fourth preset difference and the fifth preset difference are less than or equal to the first preset difference, and their specific sizes are not limited. The relative positions of the two in the figure are only for the convenience of understanding.

[0156] It should be understood that the difference in the present invention essentially refers to the difference between the target speed and the actual speed. Setting different difference values ​​(first difference / second difference / third difference) in different embodiments is also to facilitate understanding of how the present invention sets the grinding equipment control method accordingly under different circumstances (initial situation / after current compensation / after adjusting the acceleration cycle).

[0157] It should be understood that the preset differences in the present invention can be specifically set by the user in combination with work experience. For example, the user can adaptively adjust the preset differences in combination with different grinding equipment models, specifications, or grinding gears.

[0158] Example 2:

[0159] See also Figure 2As shown, the present invention also provides a control system for a grinding device based on a brushless motor. The system 200 includes: a speed acquisition module 201, configured to acquire a first target speed of the grinding device; acquire an actual speed and calculate a first difference between the target speed and the actual speed; a current compensation module 202, configured to perform current compensation on the grinding device when the first difference is less than a second preset difference and greater than the first preset difference. The current compensation includes: a compensation unit, configured to compensate the current of the grinding device to obtain a first compensated speed; a first judgment unit, configured to determine whether a second difference between the first compensated speed and a second target speed at a current moment is greater than the first preset difference; a second judgment unit, configured to determine whether the second difference is less than a sixth preset difference when the second difference is greater than the first preset difference; a first execution unit, configured to generate a first shift signal when the second difference is greater than the sixth preset difference; and to continue to compensate the current in steps when the second difference is less than the sixth preset difference. The current compensation does not exceed the first current compensation value at each time. The sixth preset difference is greater than the first preset difference, and both the sixth preset difference and the first preset difference are predefined by the user.

[0160] In some embodiments, it also includes: a temperature monitoring unit for monitoring the body temperature of the grinding device. If the body temperature is continuously greater than a preset temperature threshold during a first time period, the current of the grinding device is limited; if the body temperature is continuously less than the preset temperature threshold during a second time period, the current limiting is stopped.

[0161] In some embodiments, it also includes: a reciprocating grinding cycle unit, used to control the grinding equipment according to the reciprocating grinding cycle, wherein one reciprocating grinding cycle includes: a gear acceleration cycle T and a gear deceleration cycle T; an acceleration cycle acquisition unit, used to obtain the gear acceleration cycle T in the first time period; obtain the corresponding multiple actual speeds and the fourth target speed within the gear acceleration cycle T; a gear cycle adjustment unit, used to calculate multiple speed ratios between the actual speed and the target speed within the gear acceleration cycle T, and if the number of speed ratios greater than the first ratio does not exceed a preset number, shortening the gear acceleration cycle T.

[0162] In some embodiments, the system further includes: an acceleration period lengthening unit configured to lengthen the gear acceleration period T when the number of the speed ratios greater than the first ratio exceeds a preset number.

[0163] In some embodiments, it also includes: a speed acquisition subunit, used to obtain multiple actual speeds and multiple third target speeds in the second time period; a speed difference calculation subunit, used to calculate the third difference between the multiple actual speeds and the multiple third target speeds; a gear acceleration cycle adjustment subunit, used to extend the gear acceleration cycle T when the difference is less than the fifth preset difference.

[0164] In some embodiments, it also includes: a first prompt signal generating unit, used to determine whether the first difference between the target speed and the actual speed is less than a fourth preset difference; if so, generating a first prompt signal; a first control signal generating unit, used to generate a first control signal if the duration of the first prompt signal exceeds a preset threshold time, and the first control signal is used to control the main power switch of the grinding equipment.

[0165] In some embodiments, it also includes: a posture adjustment prompt generation unit, which is used to generate a polishing posture adjustment prompt if the first difference is greater than the second preset difference and less than the third preset difference; a forced shutdown unit, which is used to determine whether the target speed exceeds the polishing speed threshold of the polishing device if the first difference is greater than the third preset difference; if so, force shutdown.

[0166] It is understood that, in the absence of any conflict, the control method in the above embodiments of the present invention can be applied to the field of electric screwdrivers, and will not be described in detail here. For example, the multiple current compensation schemes in the above embodiments can all be applied to the control of electric screwdrivers.

[0167] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0168] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a computer terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0169] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for controlling a grinding device based on a brushless motor, characterized in that: include: Obtaining a first target speed of the grinding equipment; Acquire an actual speed, and calculate a first difference between the first target speed and the actual speed; If the first difference is smaller than the second preset difference and larger than the first preset difference, current compensation is performed on the grinding device, and the current compensation includes the steps of: Compensating the current of the grinding device to obtain a first compensation speed; determining whether a second difference between the first compensation speed and a second target speed at the current moment is greater than the first preset difference; If the second difference is greater than the first preset difference, determining whether the second difference is less than a sixth preset difference; If it is greater than the sixth preset difference, generating a first gear shift signal; If it is less than the sixth preset difference, then continue to compensate the current in batches; wherein each compensation current does not exceed the first current compensation value; The sixth preset difference is greater than the first preset difference, and both the sixth preset difference and the first preset difference are predefined by a user.

2. A method for controlling a grinding device based on a brushless motor according to claim 1, characterized in that: Before generating the first shift signal, the method further includes: monitoring the temperature of the grinding device, and limiting the current of the grinding device if the temperature of the grinding device is continuously greater than or equal to a preset temperature threshold; If the body temperature is continuously lower than the preset temperature threshold, current limiting is stopped.

3. The method for controlling a grinding device based on a brushless motor according to claim 1, wherein: include: Controlling the grinding device according to a reciprocating grinding cycle, wherein one reciprocating grinding cycle includes: a gear acceleration cycle T and a gear deceleration cycle T; Obtaining the gear acceleration period T during the first time period; Obtaining a plurality of actual speeds and a fourth target speed corresponding to the gear acceleration period T; A plurality of speed ratios between the actual speed and the fourth target speed within the gear acceleration period T are calculated, and if the number of the speed ratios greater than a first ratio does not exceed a preset number, the gear acceleration period T is shortened.

4. A method for controlling a grinding device based on a brushless motor according to claim 3, characterized in that: Also includes: If the number of the speed ratios greater than the first ratio exceeds a preset number, the gear acceleration period T is lengthened.

5. A method for controlling a grinding device based on a brushless motor according to claim 4, characterized in that: include: Acquire multiple actual speeds and multiple third target speeds in a second period; calculating third differences between the plurality of actual speeds and the plurality of third target speeds; When the third difference is less than the fifth preset difference, the gear acceleration period T is lengthened.

6. The method for controlling a grinding device based on a brushless motor according to claim 1, wherein: include: determining whether the first difference between the first target speed and the actual speed is less than a fourth preset difference; If so, generating a first prompt signal; If the duration of the first prompt signal exceeds a preset threshold time, a first control signal is generated, and the first control signal is used to control the main power switch of the grinding device.

7. The method for controlling a grinding device based on a brushless motor according to claim 1, wherein: include: If the first difference is greater than the second preset difference and less than the third preset difference, a polishing posture adjustment prompt is generated; If the first difference is greater than the third preset difference, determining whether the first target speed exceeds a grinding speed threshold of the grinding device; If so, force shutdown.

8. A grinding equipment control system based on a brushless motor, characterized in that: The system comprises: A speed acquisition module is used to acquire a first target speed of the grinding device; acquire an actual speed, and calculate a first difference between the target speed and the actual speed; A current compensation module is configured to perform current compensation on the grinding device when the first difference is less than the second preset difference and greater than the first preset difference, wherein the current compensation includes: a compensation unit, configured to compensate the current of the grinding device to obtain a first compensation speed; a first determining unit, configured to determine whether a second difference between the first compensation speed and a second target speed at a current moment is greater than the first preset difference; a second judging unit, configured to judge whether the second difference is less than a sixth preset difference when the second difference is greater than the first preset difference; The first execution unit is configured to generate a first shift signal when the current is greater than the sixth preset difference; and to continue compensating the current in stages when the current is less than the sixth preset difference; wherein each compensation current does not exceed the first current compensation value; wherein the sixth preset difference is greater than the first preset difference, and both the sixth preset difference and the first preset difference are predefined by a user.

9. A brushless motor-based polishing equipment control system according to claim 8, characterized in that: Also includes: The temperature monitoring unit is used to monitor the body temperature of the grinding device. If the body temperature is continuously greater than a preset temperature threshold, the current of the grinding device is limited; if the body temperature is continuously less than the preset temperature threshold, the current limiting is stopped.

10. A brushless motor-based polishing equipment control system according to claim 8, characterized in that: Also includes: A reciprocating grinding cycle unit, configured to control the grinding device according to a reciprocating grinding cycle, wherein one reciprocating grinding cycle includes a gear acceleration cycle T and a gear deceleration cycle T; an acceleration cycle acquiring unit, configured to acquire the gear acceleration cycle T in the first time period; and acquire a plurality of actual speeds and a fourth target speed corresponding to the gear acceleration cycle T; The gear cycle adjustment unit is used to calculate multiple speed ratios between the actual speed and the target speed within the gear acceleration cycle T, and shorten the gear acceleration cycle T if the number of the speed ratios greater than the first ratio does not exceed a preset number.

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