Motor brake device of dust collector, dust collector and controller

Abstract

The utility model provides a motor brake device of a dust collector, the dust collector and a controller, and relates to the technical field of dust collectors, the motor brake device comprises a motor, a bridge arm structure, a power supply battery and the controller; the bridge arm structure comprises a first switching device and a second switching device; the first switching device is electrically connected with the second switching device; the power supply battery is electrically connected with the motor through the bridge arm structure, the controller is electrically connected with the bridge arm structure, and the controller is used for controlling the second switching device to be in an on-off state and controlling the first switching device to be in an off state when the motor brakes, and current output by the motor flows back to the power supply battery when the second switching device is in the on-off state; the on-off state is the state that switching is conducted between the on state and the off state based on pulse width modulation in a unit period, the motor of the dust collector is controlled to conduct braking based on the structural design of the motor braking device and an active braking adjusting mode based on pulse width modulation, and rapid and effective motor braking is achieved.

Description

Technical Field

[0001] This utility model relates to the field of vacuum cleaner technology, and in particular to a motor braking device, a vacuum cleaner and a controller for a vacuum cleaner. Background Technology

[0002] In the design of vacuum cleaners, the way the motor stops is one of the important factors affecting user experience and product performance.

[0003] In related technologies, vacuum cleaners typically use a natural coaster stopping method, which means that after the power is turned off, the motor naturally decelerates until it stops by relying on its own mechanical resistance and air resistance.

[0004] However, the above method may result in a slow stopping process due to the large rotational inertia of the rotor and fan blades inside the motor. Utility Model Content

[0005] This utility model provides a motor braking device for a vacuum cleaner, a vacuum cleaner and a controller. Through the coordinated work of the motor, bridge arm structure, power supply battery and controller, the vacuum cleaner motor is controlled to brake by active braking adjustment based on pulse width modulation, so that the vacuum cleaner motor can still complete fast and effective braking while maintaining a large rotational inertia of the rotor and fan blades.

[0006] In a first aspect, this utility model provides a motor braking device for a vacuum cleaner, the motor braking device including a motor, a bridge arm structure, a power supply battery and a controller; the bridge arm structure includes a first switching device and a second switching device; the first switching device and the second switching device are electrically connected;

[0007] The power supply battery is electrically connected to the motor through the bridge arm structure, and the controller is electrically connected to the bridge arm structure. The controller is used to control the second switching device to be in the on state and the first switching device to be in the off state when the motor is braking, and when the second switching device is in the on state, the current output by the motor flows back to the power supply battery; the switching state is a state that switches between the on state and the off state based on pulse width modulation within a unit cycle.

[0008] Compared with existing technologies, this invention, based on the design of a motor braking device, enables the motor to decelerate and stop quickly through current recirculation and electrical control, shortening the stopping time and meeting the vacuum cleaner's requirement for rapid motor braking. It avoids the prolonged deceleration process of traditional natural coasting methods. Furthermore, the energy recovered during braking is stored back in the battery, reducing energy waste and improving the overall energy efficiency of the vacuum cleaner. In addition, the braking process reduces vacuum cleaner movement or damage caused by inertia and minimizes mechanical wear, thereby extending the motor's lifespan and lowering maintenance costs.

[0009] Optionally, the bridge arm structure is a three-phase inverter, which includes a lower switch and an upper switch of the three-bridge arm. The connection terminals of the lower switch and the upper switch are electrically connected to the motor.

[0010] Therefore, as a DC-AC conversion device, the three-phase inverter converts the DC power output from the power supply battery into three-phase AC power, which can drive the three-phase motor in a balanced and stable manner. Moreover, the use of the inverter allows the motor's kinetic energy to be recovered to the power supply battery more effectively, thereby improving energy utilization efficiency. This not only shortens braking time but also extends the battery's range.

[0011] Optionally, the motor braking device also includes a current detection circuit, which is electrically connected to the bridge arm structure and is used to detect the bus current and / or bridge arm current.

[0012] Therefore, the current detection circuit can provide real-time current feedback data, enabling the controller to dynamically adjust the braking force and speed according to the actual current situation, thereby improving the smoothness and efficiency of the braking process. Moreover, by monitoring the bus current and / or bridge arm current, the energy recovery process can be better managed, ensuring that the return current of the circuit is always within a safe level to prevent the circuit from burning out, reducing the impact of the energy recovery process on the circuit, and ensuring that the motor kinetic energy is effectively returned to the power supply battery, thereby improving the energy utilization efficiency of the motor braking device.

[0013] Optionally, the controller includes a proportional-integral control unit, which implements pulse width modulation in a closed-loop manner to control the magnitude of the bus current and / or bridge arm current.

[0014] In this way, because the PI control unit can precisely control the current magnitude, the motor braking process is more stable and controllable, which is crucial for achieving fast and smooth braking. The P control part in the PI control unit can quickly respond to current changes, ensuring that the closed-loop control system can quickly adapt to load changes or external disturbances. The I control part adjusts by accumulating errors, eliminating the steady-state error of the closed-loop control system, ensuring that the current can reach the set value, improving control accuracy, and thus enabling the closed-loop control system to automatically adjust to cope with changes, improving the system's stability and robustness, reducing sensitivity to changes in external conditions, and through precise current control, the closed-loop control system can also more effectively manage the energy recovery process and improve the utilization efficiency of the power supply battery.

[0015] Optionally, the controller also includes a pulse width modulation generator; the proportional-integral control unit is electrically connected to the pulse width modulation generator, the proportional-integral control unit is used to control the pulse width modulation generator to generate a pulse width modulation signal, and the pulse width modulation signal is used to indicate that the first switching device and the second switching device are in a switching state, an on state, or an off state.

[0016] Therefore, by combining a PI control unit and a PWM generator, and controlling the PWM generator to generate a PWM signal, precise current control can be achieved. This helps to achieve fast and smooth motor braking. Moreover, PWM control can effectively regulate current, reduce energy loss, and improve braking efficiency. In addition, precise current control can also reduce impact and wear on mechanical parts, extending the service life of the vacuum cleaner.

[0017] Optional, proportional-integral control unit, specifically used for:

[0018] A pulse width modulation duty cycle is generated based on the detected bus current and / or bridge arm current, and the pulse width modulation duty cycle is sent to the pulse width modulation generator so that the pulse width modulation generator can generate a pulse width modulation signal based on the pulse width modulation duty cycle.

[0019] In the case where the pulse width modulation signal is used to indicate that the second switching device is in a switching state, the pulse width modulation duty cycle is determined by the initial pulse width modulation duty cycle, which is determined based on the initial speed of the motor during braking and the preset current peak value. The pulse width modulation duty cycle is less than the first threshold.

[0020] Therefore, by dynamically adjusting the PWM duty cycle, precise control of the current can be achieved. Furthermore, by controlling the feedback current, the braking is controlled, ensuring the safety of the motor braking device while achieving rapid braking. Moreover, this invention ensures a smooth transition from start to finish of the braking process through the setting and gradual adjustment mechanism of the initial duty cycle, reducing impact and vibration. This smooth braking process can also reduce wear on mechanical parts, thereby extending the service life of the vacuum cleaner.

[0021] Furthermore, this dynamic adjustment of the PWM duty cycle enables the motor braking device to adapt to different load conditions and braking requirements, thereby improving the adaptability and flexibility of the motor braking device.

[0022] Optionally, the current detection circuit includes a first resistor and / or at least one second resistor; one end of the first resistor is electrically connected to the positive terminal of the power supply battery, and the other end of the first resistor is electrically connected to the first switching device; one end of the at least one second resistor is electrically connected to one of the switches of the second switching device, and the other end of the at least one second resistor is electrically connected to the negative terminal of the power supply battery.

[0023] In this way, the current detection circuit, based on the design of the first resistor and / or at least one second resistor, can monitor the current flow in the circuit corresponding to the motor braking device in real time. This allows the controller to dynamically adjust the state of the switching devices based on the real-time current data, achieving more precise motor control and braking. Furthermore, by monitoring the current, the motor braking device can better manage energy flow, optimize the energy recovery process, and improve battery utilization efficiency.

[0024] In addition, the detected current data can be used to diagnose faults, help identify potential problems in motors or three-phase inverters, and enable timely maintenance and repair.

[0025] Optionally, the controller is also used for:

[0026] Based on the detected current speed of the motor, the current speed is compared with a first preset speed;

[0027] When the current rotational speed is determined to be less than or equal to the first preset speed, the motor is controlled to brake.

[0028] When the current rotational speed is determined to be greater than the first preset speed, the first and second switching devices are both turned off until the motor speed is less than or equal to the first preset speed.

[0029] Therefore, in this invention, by avoiding direct braking at higher speeds, the impact of current on the circuit and the power supply battery can be reduced, mechanical wear and failure risks can be reduced, and the aforementioned intelligent braking control logic can ensure braking at the appropriate time, improving the smoothness and efficiency of the braking process.

[0030] Furthermore, the design of this invention temporarily shuts off the switching device at high speeds, allowing the motor to decelerate naturally. This helps control the current in the circuit during braking, thus extending the service life of the motor and related components by avoiding excessive mechanical and thermal stress.

[0031] Optionally, the controller is specifically used for:

[0032] When the motor starts braking, the second switching device is switched from the off state to the on state, while the first switching device remains in the off state.

[0033] In this way, by adjusting only the state of the second switching device, the motor can smoothly switch into the braking process. Through this staged control strategy, the motor braking device can provide optimized performance when braking begins, ensuring the safety, efficiency and reliability of the motor.

[0034] Optionally, the controller is also used for:

[0035] Based on the detected current speed of the motor, the current speed is compared with the second preset speed;

[0036] When the current rotational speed is determined to be greater than the second preset speed, the motor is controlled to brake.

[0037] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device is controlled to be in the off state and the second switching device is controlled to be in the target state. The target state includes a first state and a second state. The first state is that the second switching device is in the fully on state. The second state is that within a unit cycle, the second switching device is in the on state for a first duration and in the off state for a second duration. The first duration is longer than the second duration.

[0038] Therefore, when the motor reaches a given low speed or is close to stopping, more precise current control and braking force can be achieved by giving a particularly high PWM duty cycle or fully turning on the second switching device, ensuring rapid braking of the motor. Furthermore, at low speeds, rapid control of the motor braking can also reduce vibration and noise, making it less noticeable to the user and improving the user's perception, control, and overall experience.

[0039] It should be noted that a particularly high PWM duty cycle means that the signal is at a high level for most of the time during a PWM cycle. During the high level period, the MOSFET is in the on state, while it is in the off state for a small part of the time.

[0040] Furthermore, by selecting the appropriate target state under different operating conditions, this invention can flexibly adapt to different braking requirements and load conditions, thereby improving the stability of the motor braking device and reducing vibration and noise.

[0041] Optionally, when the pulse width modulation signal is used to indicate that the second switching device is in the second state, the pulse width modulation duty cycle is less than the second threshold.

[0042] The second threshold is used to ensure that a particularly high PWM duty cycle is directly applied during braking, so that the maximum braking torque can be provided in the shortest time, thereby achieving the effect of quickly stopping the motor.

[0043] Optionally, the controller is used for:

[0044] Based on the detected current speed of the motor, the current speed is compared with the second preset speed;

[0045] When the current rotational speed is determined to be greater than the second preset speed, the motor is controlled to brake.

[0046] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device is controlled to be in the off state and the second switching device is controlled to be in the target state. The target state includes the first state and the second state. The first state is that the second switching device is in the fully on state. The second state is that within a unit cycle, the second switching device is in the on state for a first duration and in the off state for a second duration. The first duration is longer than the second duration.

[0047] When the pulse width modulation signal is used to indicate that the second switching device is in the second state, the pulse width modulation duty cycle is less than the second threshold.

[0048] The second threshold is greater than the first threshold.

[0049] In this way, by setting different thresholds, the control strategy can be dynamically adjusted according to different working conditions and needs, thereby improving the flexibility and adaptability of the motor braking device. In addition, the setting of the first threshold is to allow the current to be controlled within a safe and adjustable range, while setting the second threshold to be greater than the first threshold allows for a higher duty cycle under specific conditions to achieve rapid and complete braking of the motor, while ensuring that it does not exceed the safe range, thus protecting the safety of the motor and electronic components.

[0050] Optionally, the controller is specifically used for:

[0051] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device is controlled to remain in the off state, and the second switching device is controlled to switch from the on state to the target state.

[0052] In this way, the motor braking device can dynamically adjust the braking strategy according to the actual speed to adapt to different operating conditions and needs. Especially at low speeds or near complete stop, by adjusting the state of the second switching device, more precise current control and braking force can be achieved, resulting in more stable control of the braking process. This ensures that the motor is brought to a rapid and complete stop while reducing vibration and noise. Through this control strategy, the motor braking device can provide optimized braking performance at low speeds, ensuring the safety, efficiency, and reliability of the motor.

[0053] Secondly, this utility model provides a vacuum cleaner, including a motor braking device as described in any of the first aspects.

[0054] Thirdly, this utility model provides a controller that is electrically connected to a bridge arm structure in a motor braking device. The bridge arm structure includes a first switching device and a second switching device. The first switching device and the second switching device are electrically connected. The controller is used to control the second switching device to be in a switching state and control the first switching device to be in a turning-off state when the motor is braking. When the second switching device is in a switching state, the current output by the motor flows back to the power supply battery in the motor braking device. The switching state is a state that switches between an on state and a off state based on pulse width modulation within a unit cycle.

[0055] It should be noted that the second and third aspects of this utility model correspond to the technical solutions of the first aspect of this utility model, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be repeated here.

[0056] In summary, this utility model provides a motor braking device, a vacuum cleaner, and a controller for a vacuum cleaner. It controls the vacuum cleaner's motor to brake using active braking adjustment based on pulse width modulation (PWM). The motor braking device includes a motor, a bridge arm structure, a power supply battery, and a controller. The bridge arm structure includes a first switching device and a second switching device. Under normal operating conditions, the motor obtains electrical energy from the power supply battery through the bridge arm structure to drive the vacuum cleaner. When braking is required, the controller receives a braking signal and initiates the braking operation. Specifically, the controller controls the second switching device to enter a switching state, switching between an on and off state based on PWM within a unit cycle. Simultaneously, the controller places the first switching device in the off state. While the second switching device is in the on / off state, the motor rotor continues to rotate due to inertia. The motor then functions as a generator, and the generated current flows back to the power supply battery through the bridge arm structure, achieving energy recovery. Through this process, the motor's kinetic energy is quickly converted into electrical energy and recovered, reducing the impact of the rotor's rotational inertia on the braking process, thus achieving rapid stopping and improving the vacuum cleaner's operational safety, especially in applications requiring frequent start-stop operations. Attached Figure Description

[0057] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale. The drawings are as follows:

[0058] Figure 1 An application scenario diagram of a motor braking device for a vacuum cleaner provided by this utility model;

[0059] Figure 2This utility model provides a schematic diagram of the structure of a motor braking device for a vacuum cleaner. Figure 1 ;

[0060] Figure 3 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 2 ;

[0061] Figure 4 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 3 ;

[0062] Figure 4 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 5 ;

[0063] Figure 5 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 6 ;

[0064] Figure 6 A circuit diagram corresponding to the motor braking device of a vacuum cleaner provided by this utility model;

[0065] Figure 7 A partial circuit diagram of the motor braking device of another vacuum cleaner provided by this utility model;

[0066] Figure 8 This is a schematic diagram illustrating the effect of an electric motor brake provided by this utility model.

[0067] The accompanying drawings have illustrated specific embodiments of the present invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art through reference to specific embodiments.

[0068] Figure label:

[0069] 100-Motor brake device; 200-Vacuum cleaner; 101-Motor; 102-Bridge arm structure; 103-Power supply battery; 104-Controller; 105-Current detection circuit; 11-First switching device; 12-Second switching device; 13-Proportional-integral control unit; 14-Pulse width modulation generator; 15-First resistor; 16-Second resistor. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0071] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0072] The technical solution of this utility model and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The utility model will now be described with reference to the accompanying drawings.

[0073] The following explains the technical terms involved in this utility model.

[0074] Natural stop: This can refer to the phenomenon in an electric motor-driven system where, when the motor stops applying driving force, the system continues to move due to inertia until it naturally stops due to friction or other resistance.

[0075] Active braking refers to the process of quickly stopping a motor or slowing its speed by applying additional braking force, such as mechanical braking, electric braking, and regenerative braking. This utility model mainly relates to regenerative braking, which converts the kinetic energy of the motor into electrical energy and feeds it back to the power supply system to achieve deceleration.

[0076] Energy recovery: This can refer to the process where, during deceleration or braking, the electric motor reverses its direction, acts as a generator, converts kinetic energy into electrical energy, and stores it in a battery for later reuse.

[0077] In one possible implementation, the vacuum cleaner typically uses a natural coaster-stop method, where the motor naturally decelerates until it stops after the power is turned off, relying on its own mechanical resistance and air resistance.

[0078] However, the above methods may result in a slow stopping process due to the large rotational inertia of the rotor and fan blades inside the motor. For some faster stopping methods, the required rotational inertia of the rotor and fan blades is relatively small. Therefore, it is very difficult to achieve a balance between motor performance and small rotational inertia.

[0079] It should also be noted that the motor of the natural scooter parking mode usually takes 2 to 3 seconds to turn off, which is relatively slow and has a long trailing sound, affecting the user's perception and experience.

[0080] To address the aforementioned problems, this utility model provides a motor braking device for a vacuum cleaner. This device brakes the motor without relying on the rotational inertia of the rotor and fan blades. Instead, it controls the vacuum cleaner motor's braking through active braking adjustment based on pulse width modulation (PWM). Specifically, this motor braking device achieves rapid and effective motor braking through the coordinated operation of the motor, bridge arm structure, power supply battery, and controller. In normal operation, the motor obtains electrical energy from the power supply battery via the bridge arm structure to drive the vacuum cleaner. When braking is required, the controller receives a braking signal and initiates the braking operation. Specifically, the controller controls the second switching device to enter a switching state, switching between on and off states within a unit cycle based on PWM. Simultaneously, the controller sets the first switching device to the off state. While the second switching device is in the on / off state, the motor rotor continues to rotate due to inertia, and the motor then functions as a generator. The generated current flows back to the power supply battery through the bridge arm structure, achieving energy recovery. In this way, through the above process, the kinetic energy of the motor is quickly converted into electrical energy and recovered, reducing the impact of the rotor's rotational inertia on the braking process, thereby achieving rapid stopping and improving the operational safety of the vacuum cleaner, especially in application scenarios that require frequent start-stop.

[0081] Furthermore, since the braking of the motor is mainly achieved through electrical means, the reliance on mechanical braking components is reduced, thereby reducing mechanical wear and maintenance costs.

[0082] For example, Figure 9 An application scenario diagram of a motor braking device for a vacuum cleaner provided by this utility model is shown, such as... Figure 1 As shown, the application scenario is a household cleaning scenario, which includes a vacuum cleaner 200. The vacuum cleaner 200 has a built-in motor braking device 100, which includes a motor, a bridge arm structure, a power supply battery, and a controller.

[0083] After the user finishes cleaning the surfaces in the living room with the vacuum cleaner 200, if they want to turn off the vacuum cleaner 200, they can do so by clicking the off button on the vacuum cleaner 200 or sending a voice control command to the vacuum cleaner 200. This will cause the vacuum cleaner 200 to generate a braking signal. Upon receiving the braking signal, the controller will begin to execute the braking operation. That is, through the coordinated work of the motor, the bridge arm structure, the power supply battery, and the controller, fast and effective motor braking is achieved, thereby realizing active braking.

[0084] It should be noted that the application scenarios of the motor braking device for vacuum cleaners provided by this utility model are not specifically limited. It can also be applied to a series of scenarios that require dust removal, such as shopping malls, schools, and hospitals.

[0085] Based on the above application scenarios, the vacuum cleaner 200 can convert the kinetic energy of the motor into electrical energy and store it back in the battery during braking. This energy recovery mechanism improves the overall energy efficiency of the vacuum cleaner 200, extends battery life, reduces charging frequency, and, through electrical control, quickly achieves motor deceleration and stopping, greatly shortening stopping time. The specific structure of the motor braking device 100 is as follows: Figure 1 As shown, Figure 2 This utility model provides a schematic diagram of the structure of a motor braking device for a vacuum cleaner. Figure 2 ,like Figure 1 As shown, the motor braking device 100 includes a motor 101, a bridge arm structure 102, a power supply battery 103, and a controller 104; the bridge arm structure 102 includes a first switching device 11 and a second switching device 12; the first switching device 11 and the second switching device 12 are electrically connected.

[0086] The power supply battery 103 is electrically connected to the motor 101 through the bridge arm structure 102, and the controller 104 is electrically connected to the bridge arm structure 102. The controller 104 is used to control the second switching device 12 to be in the on state and control the first switching device 11 to be in the off state when the motor 101 is braking. When the second switching device 12 is in the on state, the current output by the motor 101 flows back to the power supply battery 103. The switching state is a state that switches between the on state and the off state based on pulse width modulation within a unit cycle.

[0087] When the vacuum cleaner is working normally, the power supply battery 103 supplies power to the motor 101 through the bridge arm structure 102, and the state of the first switching device 11 and the second switching device 12 is controlled by the controller 104 to maintain the normal operation of the motor.

[0088] It should be noted that this utility model does not limit the specific device corresponding to the bridge arm structure 102. For example, the bridge arm structure 102 can be a three-bridge arm structure or a four-bridge arm structure, and different bridge arm structures correspond to different device types.

[0089] It should also be noted that active braking requires an energy-absorbing device to absorb energy. This utility model uses a power supply battery 103 to absorb the feedback energy of the motor braking, that is, to absorb the feedback current. After the motor 101 starts braking, the current will flow back to the power supply battery 103 when the second switching device 12 is in the off state, and the controller 104 controls the magnitude of the return current.

[0090] Optionally, the first switching device 11 may include at least one metal-oxide-semiconductor (MOS) transistor, and the second switching device 12 may also include at least one MOS transistor. Both are used to control the on and off of the current. Since the MOS transistor can quickly switch states under pulse width modulation control, it can achieve precise regulation of the speed and torque of the motor 101. Moreover, the MOS transistor has low on-resistance and fast switching speed, which can efficiently perform energy conversion and reduce energy loss. Due to the high-efficiency energy conversion characteristics of the MOS transistor, the heat loss in the bridge arm structure 102 is low, which simplifies the thermal management design. Therefore, in the bridge arm structure 102, the MOS transistor is used as a switching device, and by quickly switching the on and off states of the MOS transistor, precise control of the current of the motor 101 can be achieved.

[0091] It should be noted that this utility model does not limit the specific type of switching device or MOSFET corresponding to the first switching device 11 and the second switching device 12. For example, they can be N-channel enhancement-mode MOSFETs, P-channel enhancement-mode MOSFETs, etc., as long as they can control the current switching.

[0092] For example, when the motor 101 needs to stop working, the controller 104 initiates the braking process. The controller 104 controls the second switching device 12 to enter the switching state, that is, it frequently switches between the on and off states based on pulse width modulation. At the same time, the first switching device 11 is placed in the off state. When the second switching device 12 is in the switching state, the kinetic energy of the motor 101 is converted into electrical energy and flows back to the power supply battery 103 in the form of current. This energy recovery mechanism converts the kinetic energy of the motor 101 into electrical energy and stores it back in the battery, thereby improving energy efficiency.

[0093] In this way, due to the current return and electrical control, the motor 101 can decelerate and stop quickly, shortening the stopping time and avoiding the long deceleration process of the traditional natural coasting method. Moreover, the energy recovered during braking is stored back into the power supply battery, reducing energy waste and improving the overall energy efficiency of the vacuum cleaner 200. In addition, the above-mentioned braking process can also reduce the movement or damage of the vacuum cleaner 200 caused by inertia, and reduce mechanical wear, thereby extending the service life of the motor 101 and reducing maintenance costs.

[0094] It should be noted that, through testing of the aforementioned motor braking device 100, it was found that the vacuum cleaner can achieve a stopping speed of less than 500ms. This fast and smooth stopping process improves the user experience and avoids the discomfort caused by sudden stops or delays.

[0095] Optionally, the bridge arm structure 102 is a three-phase inverter, which includes a lower switch and an upper switch of the three-bridge arm. The connection terminals of the lower switch and the upper switch are electrically connected to the motor 101.

[0096] Since the three-phase inverter consists of a lower switch and an upper switch of the three bridge arms, each bridge arm can correspond to one phase of the motor 101. Therefore, there are a total of three pairs of switching devices. The connection terminals of the lower and upper switches of the three bridge arms are electrically connected to the motor 101. This means that the three-phase inverter can directly control the current flow of each phase of the motor 101. Thus, by controlling the switching state of the three-phase inverter, the controller 104 can accurately adjust the operating state of the motor 101. Especially during braking, the three-phase inverter achieves current return and kinetic energy consumption by adjusting the on and off states of the lower and upper switches of the three bridge arms.

[0097] Among them, the lower switch of the three bridge arms is the second switching device 12, which may include three lower bridge metal-oxide-semiconductor MOSFETs, and the upper switch of the three bridge arms is the first switching device 11, which may include three upper bridge MOSFETs.

[0098] It should be noted that this utility model does not limit the specific device types corresponding to the lower and upper transistor switches of the three-arm bridge. For example, an insulated gate bipolar transistor (IGBT) can also be used as the upper and lower transistor switches of the three-arm bridge.

[0099] Therefore, as a DC-AC conversion device, the three-phase inverter converts the DC power output from the power supply battery into three-phase AC power, which can drive the three-phase motor in a balanced and stable manner. Moreover, the use of the inverter allows the kinetic energy of the motor 101 to be recovered to the power supply battery 103 more effectively, thereby improving energy utilization efficiency. This not only shortens the braking time but also extends the range of the power supply battery 103.

[0100] Optional, Figure 2 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 3 ,like Figure 2 As shown, the motor brake device 100 includes, in addition to Figure 3In addition to the structure shown, the motor braking device 100 also includes a current detection circuit 105, which is electrically connected to the bridge arm structure 102. The current detection circuit 105 is used to detect the bus current and / or the bridge arm current.

[0101] In this invention, the bus current refers to the current flowing through the DC bus of the bridge arm structure 102. By detecting the bus current, the current demand and load of the entire motor braking device 100 can be understood. The bridge arm current refers to the current flowing through each bridge arm. By detecting the bridge arm current, the current distribution of each phase and the working state of the motor can be accurately understood.

[0102] In this invention, the current detection circuit 105 can feed back the detected current data to the controller 104, so that the controller 104 can adjust the state of the switching device according to the current data to control the braking process of the motor.

[0103] Therefore, the current detection circuit 105 can provide real-time current feedback data, enabling the controller 104 to dynamically adjust the braking force and speed according to the actual current situation, thereby improving the smoothness and efficiency of the braking process. Moreover, by monitoring the bus current and / or bridge arm current, the energy recovery process can be better managed, ensuring that the return current of the circuit is always within a safe level to prevent the circuit from burning out, reducing the impact of the energy recovery process on the circuit, and ensuring that the kinetic energy of the motor 101 is effectively returned to the power supply battery 103, thereby improving the energy utilization efficiency of the motor braking device 100.

[0104] Optional, Figure 2 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 4 ,like Figure 3 As shown, the motor braking device 100 includes a motor 101, a bridge arm structure 102, a power supply battery 103, and a controller 104; the bridge arm structure 102 includes a first switching device 11 and a second switching device 12; the controller 104 includes a proportional-integral control unit 13, which implements pulse width modulation based on a closed-loop method to control the magnitude of the bus current and / or the bridge arm current.

[0105] The proportional-integral control unit 13 is part of a closed-loop control system, which is a system in the controller 104. The closed-loop mode means that the system continuously monitors the magnitude of the bus current and / or bridge arm current and compares it with the set value to adjust the state of the switching devices. For example, after the motor 101 starts braking, the controller 104 will immediately start the closed-loop control system to control the return current based on the closed-loop mode.

[0106] Therefore, this invention can realize pulse width modulation based on a closed-loop control system to adjust the feedback current or adjust the peak current of the three-phase bridge arm, so as to brake and stop the machine in a controlled manner. This method ensures that the active braking feedback current is controlled and the bridge arm current is controlled, thereby achieving smooth and fast braking.

[0107] Optionally, the proportional-integral (PI) control unit 13 can also be replaced with a proportional-integral-derivative (PID) control unit, wherein the PI control unit consists of a proportional (P) control part and an integral (I) control part, and the PID control unit consists of a proportional (P) control part, an integral (I) control part and a derivative (D) control part.

[0108] The P control section provides control proportional to the current error, the I control section eliminates steady-state error by accumulating the integral of the error over time, and the D control section predicts the future trend of the error by differentiating the rate of change of the error, thereby providing early correction. This can improve the dynamic response of the closed-loop control system and reduce overshoot and oscillation. Therefore, the PID control unit has both the functions of the PI control unit 13 and the advantages of differentiation, and can provide better dynamic and steady-state performance. However, the PI control unit 13 is simpler in structure and easier to implement than the PID control unit, while the PID control unit has a more complex structure, more difficult parameter adjustment, and may require more computing resources. Therefore, this invention can choose to use either the PID control unit or the PI control unit 13 according to application requirements or product performance parameters.

[0109] For example, the PI control unit 13 can control the magnitude of the bus current and / or bridge arm current by adjusting the state of the first switching device 11 and the second switching device 12. This control can be achieved by pulse width modulation (PWM), such as by adjusting the on-time and frequency of the switching devices to regulate the current.

[0110] Optionally, the bus current is typically an average value, and the PI control unit 13 can adjust the magnitude of this average value through pulse width modulation.

[0111] In this way, because the PI control unit 13 can accurately control the current magnitude, the braking process of the motor 101 is more stable and controllable, which is crucial for achieving fast and smooth braking. The P control part in the PI control unit 13 can quickly respond to current changes, ensuring that the closed-loop control system can quickly adapt to load changes or external disturbances. The I control part adjusts by accumulating errors to eliminate the steady-state error of the closed-loop control system, ensuring that the current can reach the set value, improving control accuracy, and thus enabling the closed-loop control system to automatically adjust to cope with changes, improving the stability and robustness of the system, reducing sensitivity to changes in external conditions, and through precise current control, the closed-loop control system can also more effectively manage the energy recovery process and improve the utilization efficiency of the power supply battery 103.

[0112] Optional, Figure 4 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 5 ,like Figure 4 As shown, the motor braking device 100 includes a motor 101, a bridge arm structure 102, a power supply battery 103, and a controller 104; the bridge arm structure 102 includes a first switching device 11 and a second switching device 12; the controller 104 includes, in addition to, a motor 101, a bridge arm structure 102, a first switching device 11, and a second switching device 12; the controller 104 includes, in addition to, Figure 5 In addition to the structure shown, the controller 104 also includes a pulse width modulation generator 14; the proportional-integral control unit 13 is electrically connected to the pulse width modulation generator 14, the proportional-integral control unit 13 is used to control the pulse width modulation generator 14 to generate a pulse width modulation signal, and the pulse width modulation signal is used to indicate that the first switching device 11 and the second switching device 12 are in a switching state, an on state, or an off state.

[0113] The PI control unit 13 is used to calculate the current error and generate a control signal based on the current error. The control signal is then sent to the pulse width modulation generator (PWM generator) 14. After receiving the control signal from the PI control unit 13, the PWM generator 14 generates a PWM signal based on the control signal. The PWM signal is a modulation signal that can control the magnitude and direction of the current by changing the width of the pulse.

[0114] Optionally, the control signal can be a PWM duty cycle, which is the ratio of the duration of the high level in the PWM signal to the entire cycle, and determines the conduction time of the switching device. This invention does not specifically limit the type of control signal, which can control the PWM generator 14 to generate a pulse width modulation signal. The control signal can also be an analog signal.

[0115] It should be noted that by adjusting the PWM duty cycle to generate the PWM signal, the braking force and speed of the motor 101 can be controlled more flexibly to adapt to different working conditions.

[0116] For example, when the PI control unit 13 generates a continuous PWM duty cycle between 0 and 1, it controls the PWM generator 14 to generate a PWM signal that controls the first switching device and the second switching device to be in a switching state, an on state, or an off state.

[0117] Therefore, by combining the PI control unit 13 and the PWM generator 14, the PWM generator 14 generates a PWM signal, enabling precise current control. This facilitates fast and smooth motor braking. Furthermore, the PWM control method effectively regulates the current, reduces energy loss, and improves braking efficiency. In addition, precise current control can reduce impact and wear on mechanical components, extending the service life of the vacuum cleaner 200.

[0118] Optional, the proportional-integral control unit 13 is specifically used for:

[0119] A pulse width modulation duty cycle is generated based on the detected bus current and / or bridge arm current, and the pulse width modulation duty cycle is sent to the pulse width modulation generator so that the pulse width modulation generator can generate a pulse width modulation signal based on the pulse width modulation duty cycle.

[0120] In the case where the pulse width modulation signal is used to indicate that the second switching device is in the switching state, the pulse width modulation duty cycle is determined by the initial pulse width modulation duty cycle. The initial pulse width modulation duty cycle is determined based on the initial speed of the motor during braking and the preset current peak value. The pulse width modulation duty cycle is less than the first threshold value, which is used to ensure that the current is controlled within a safe and adjustable range during the initial braking phase.

[0121] Optionally, when the PWM signal is used to indicate that the second switching device is in a switching state, the initial PWM duty cycle is a digital signal that is less than the first threshold or a specific threshold. The PWM duty cycle can be positively correlated with the braking time. For example, if the initial PWM duty cycle is 0.1, the PWM duty cycle will increase accordingly as the braking time increases, until it approaches the first threshold, such as approaching 0.98.

[0122] It should be noted that this invention does not specifically limit the PWM duty cycle, the magnitude of the initial PWM duty cycle, or the relationship between the PWM duty cycle and the braking time; these can be set based on specific requirements.

[0123] In this invention, when the motor 101 starts braking, the initial duty cycle is determined based on the initial speed of the motor 101 and the preset current peak value. This initial duty cycle is used to set the starting conditions of the braking process to ensure the smoothness of braking.

[0124] Optionally, when the motor 101 begins braking, the PI control unit 13 dynamically assigns an initial PWM duty cycle D0 for the first motor braking based on the initial braking speed. This initial PWM duty cycle D0 is determined by the following formula:

[0125]

[0126] Among them, I target is the target peak current, which is the peak value of the bridge arm current; rpm is the initial speed of the motor when braking; L is the motor phase inductance, i.e., the inductance characteristic in the motor windings; ke is the back electromotive force constant; and fs is the switching frequency of the PWM signal.

[0127] In this way, by dynamically initializing the settings, i.e. dynamically giving the initial PWM duty cycle, the braking start current can be controlled, thereby ensuring braking consistency.

[0128] For example, the PI control unit 13 generates a PWM duty cycle based on the detected bridge arm current, and then sends the PWM duty cycle to the PWM generator 14 so that the PWM generator 14 generates an actual PWM signal based on the PWM duty cycle to control the switching device.

[0129] Therefore, by dynamically adjusting the PWM duty cycle, precise control of the current can be achieved. Furthermore, by controlling the feedback current, the braking is controlled, ensuring the safety of the motor braking device 100 while achieving rapid braking. Moreover, this invention ensures a smooth transition from start to finish of the braking process through the setting and gradual adjustment mechanism of the initial duty cycle, reducing impact and vibration. This smooth braking process can also reduce wear on mechanical parts, thereby extending the service life of the vacuum cleaner 200.

[0130] Furthermore, the dynamic adjustment of the PWM duty cycle enables the motor brake device 100 to adapt to different load conditions and braking requirements, thereby improving the adaptability and flexibility of the motor brake device 100.

[0131] Optional, Figure 6 A schematic diagram of the structure of a motor braking device for a vacuum cleaner provided by this utility model. Figure 5 ,like Figure 6As shown, the motor braking device 100 includes a motor 101, a bridge arm structure 102, a power supply battery 103, a controller 104, and a current detection circuit 105; the bridge arm structure 102 includes a first switching device 11 and a second switching device 12; the current detection circuit 105 includes a first resistor 15 and / or at least one second resistor 16; one end of the first resistor 15 is electrically connected to the positive terminal of the power supply battery 103, and the other end of the first resistor 15 is electrically connected to the first switching device 11; one end of at least one second resistor 16 is electrically connected to one of the switches of the second switching device 12, and the other end of at least one second resistor 16 is electrically connected to the negative terminal of the power supply battery 103.

[0132] One end of the first resistor 15 is connected to the positive terminal of the power supply battery 103, and the other end is connected to the first switching device 11. This connection method is used to monitor the bus current. One end of at least one second resistor 16 is connected to one of the switches of the second switching device 12, and the other end is connected to the negative terminal of the power supply battery 103. This connection method is used to monitor the current through a specific switching device, i.e., the bridge arm current.

[0133] For example, Figure 7 A circuit diagram corresponding to the motor braking device of a vacuum cleaner provided by this utility model is shown below. Figure 7 As shown, taking the bridge arm structure 102 as a three-phase inverter, the first resistor 15 is resistor R4, and at least one second resistor 16 including resistors R1, R2, and R3 as an example, the three-phase inverter includes three upper-bridge MOSFETs g1, g3, and g5, and three lower-bridge MOSFETs g2, g4, and g6. The motor M is electrically connected to the connection terminals between MOSFETs g1 and g2, between MOSFETs g3 and g4, and between MOSFETs g5 and g6, respectively. One end of resistor R4 is connected to the positive terminal of the power supply battery 103, and the other end is connected to the upper-bridge switch of the three-phase inverter. One end of resistor R1 is electrically connected to MOSFET g2, and the other end is electrically connected to the negative terminal of the power supply battery 103. One end of resistor R2 is electrically connected to MOSFET g4, and the other end is electrically connected to the negative terminal of the power supply battery 103. One end of resistor R3 is electrically connected to MOSFET g6, and the other end is electrically connected to the negative terminal of the power supply battery 103. It is easy to understand that resistors R1, R2, R3, and R4 can all function as current sensors to detect bridge arm current or bus current.

[0134] Optionally, the three upper-bridge MOSFETs g1, g3 and g5, and the three lower-bridge MOSFETs g2, g4 and g6 can be N-type MOSFETs. This invention does not limit the specific type of MOSFETs in the three-phase inverter.

[0135] Optionally, when the motor 101 starts braking, the three upper bridge MOSFETs g1, g3 and g5 are in the off state, and the three lower bridge MOSFETs g2, g4 and g6 are in the on state. The MOSFETs g2, g4 and g6 can be driven by the same PWM signal, which is given by the PI control unit 13 and the PWM generator 14.

[0136] For example, Figure 8 A partial circuit diagram of the motor braking device of another vacuum cleaner provided by this utility model is shown below. Figure 8 As shown, in Figure 7 Based on the circuit structure corresponding to the motor braking device shown, the circuit also includes a controller 104. The controller 104 includes a PI control unit c1 and a PWM generator c2. The PI control unit c1 and the PWM generator c2 are electrically connected. One end of the PI control unit c1 is connected to a resistor R4 to monitor the bus current. One end of the PWM generator c2 is connected to a three-phase inverter to send the generated PWM signal to the corresponding MOSFETs, thereby controlling the three upper bridge MOSFETs g1, g3 and g5, and the three lower bridge MOSFETs g2, g4 and g6 to be in a switching state, an on state, or a off state.

[0137] It should be noted that using resistance for current detection is a relatively simple and cost-effective method that does not require complex sensor equipment. Therefore, it can greatly reduce the cost of the motor brake device 100.

[0138] In this way, the current detection circuit 105, based on the design of the first resistor 15 and / or at least one second resistor 16, can monitor the current flow in the circuit corresponding to the motor brake device 100 in real time, so that the controller 104 can dynamically adjust the state of the switching device based on the real-time current data, thereby achieving more precise motor control and braking process. Furthermore, by monitoring the current, the motor brake device 100 can better manage energy flow, optimize the energy recovery process, and improve battery utilization efficiency.

[0139] In addition, the detected current data can also be used to diagnose faults, help identify potential problems in motor 101 or the three-phase inverter, and thus enable timely maintenance and repair.

[0140] Optionally, controller 104 is also used for:

[0141] Based on the detected current speed of motor 101, the current speed is compared with the first preset speed;

[0142] When the current rotational speed is determined to be less than or equal to the first preset speed, the motor 101 is controlled to brake.

[0143] When the current rotational speed is determined to be greater than the first preset speed, the first switching device 11 and the second switching device 12 are both turned off until the rotational speed of the motor 101 is less than or equal to the first preset speed.

[0144] In this invention, the controller 104 can detect the current speed of the motor 101 in real time. This can be achieved by a speed sensor or other speed detection devices. This invention does not specifically limit the device used to detect the speed in the controller 104. For example, the device for detecting the speed can be a Hall effect sensor or a photoelectric encoder.

[0145] Optionally, the controller 104 compares the detected current rotational speed with a first preset speed. This can be achieved by a comparator or other devices used for speed comparison. This invention does not specifically limit the devices used for speed comparison in the controller 104.

[0146] The first preset speed is a pre-set threshold used to determine when to start braking. This invention does not specifically limit the magnitude of the first preset speed, which can be set based on the actual application scenario requirements or product performance parameters. For example, the first preset speed can be set to 80krpm.

[0147] For example, the motor speed of the vacuum cleaner 200 is detected by a Hall effect sensor and converted into a voltage or digital signal. Optionally, this signal can be processed by a signal conditioning circuit, such as an amplification or filtering circuit, to become a signal suitable for the input requirements of the comparator. The comparator then receives the processed motor speed signal and compares it with the signal corresponding to the first preset speed. If the current speed is less than or equal to the first preset speed, the comparator outputs a first drive signal to cause the controller 104 to start the braking process of the motor 101. If the current speed is greater than the first preset speed, the comparator outputs a low-level second drive signal. This second drive signal is given to the PWM generator 14 to generate a PWM signal, which in turn controls the first switching device 11 and the second switching device 12 to be in the off state. This means that the motor 101 does not brake temporarily, but instead coasts naturally to decelerate until the speed drops below the first preset speed. Once the speed of the motor 101 drops to less than or equal to the first preset speed, the controller 104 can then apply further braking.

[0148] Understandably, the motor braking device can dynamically adjust the braking strategy according to the actual speed, which can adapt to different operating conditions and needs.

[0149] Therefore, in this invention, by avoiding direct braking at higher speeds, the impact of current on the circuit and the power supply battery 103 can be reduced, mechanical wear and failure risks can be reduced, and the aforementioned intelligent braking control logic can ensure braking at the appropriate time, improving the smoothness and efficiency of the braking process.

[0150] Furthermore, the design of this invention temporarily shuts off the switching devices at high speeds, allowing the motor to decelerate naturally. This helps control the current in the circuit during braking, thus extending the service life of the motor 101 and related components by avoiding excessive mechanical and thermal stress.

[0151] Optionally, controller 104 is specifically used for:

[0152] When the control motor 101 starts braking, the control second switch device 12 switches from the off state to the on state, while the first switch device 11 remains in the off state.

[0153] In this invention, before controlling the motor 101 to start braking, the controller 104 determines whether to start braking based on the detected current speed of the motor 101. When the current speed is greater than the first preset speed, the controller 104 controls the motor 101 to slide naturally, that is, controls both the first switching device 11 and the second switching device 12 to be in the off state. This corresponds to the first stage of braking. Until the current speed of the motor 101 is detected to drop below the first preset speed, the controller 104 controls the second switching device 12 to switch from the off state to the on state. This means that the second switching device starts to conduct and turn off in a closed-loop pulse width modulation manner, while the first switching device 11 remains in the off state and does not participate in the current current regulation. This corresponds to the second stage of braking.

[0154] For example, such as Figure 7 As shown, in the first stage, MOSFETs g1 to g6 receive a low PWM signal, so that all MOSFETs g1 to g6 are in the off state. In the second stage, MOSFETs g1, g3, and g5 receive a low PWM signal, and MOSFETs g1, g3, and g5 are still in the off state, while MOSFETs g2, g4, and g6 receive the same PWM signal generated based on pulse width modulation, so that MOSFETs g2, g4, and g6 switch from the off state to the switching state.

[0155] In this way, by adjusting only the state of the second switching device 12, the motor can smoothly switch into the braking process. Through this staged control strategy, the motor braking device 100 can provide optimized performance when braking begins, ensuring the safety, efficiency and reliability of the motor 101.

[0156] Optionally, controller 104 is also used for:

[0157] Based on the detected current speed of motor 101, the current speed is compared with the second preset speed;

[0158] When the current rotational speed is determined to be greater than the second preset speed, the motor is controlled to brake.

[0159] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device 11 is controlled to be in the off state and the second switching device 12 is controlled to be in the target state.

[0160] The target state usually refers to a specific switching mode, which may be an on state or a state that controls the switch with a specific high PWM duty cycle in order to achieve a rapid and complete stop of the motor 101. Its main purpose is to completely eliminate the tail noise of the motor 101.

[0161] Optionally, the target state includes a first state and a second state; the first state is that the second switching device 12 is in a fully turned-on state, and the second state is that within a unit cycle, the second switching device 12 is in a turned-on state for a first duration and in a turned-off state for a second duration; the first duration is longer than the second duration.

[0162] The second state is actually a PWM control, which controls the conduction duration of the second switching device 12 by adjusting the ratio of the on and off times, i.e. the ratio of the first duration and the second duration.

[0163] Optionally, when it is necessary to maximize current flow to achieve rapid braking, the second switching device 12 is set to the fully on state.

[0164] Optionally, when more precise control of the current is required to achieve rapid braking, the second switching device 12 is configured to alternately turn on and off within a unit cycle, and the first duration of the on state is longer than the second duration of the off state.

[0165] Optionally, the controller 104 compares the detected current rotational speed with a second preset speed. This process can also be implemented by a comparator or other devices used for speed comparison, and the present invention does not specifically limit this.

[0166] The second preset speed is a pre-set threshold used to determine the braking strategy under low-speed conditions. The second preset speed can be a very small value close to 0. This utility model does not specifically limit the size of the second preset speed, but can set it based on the actual application scenario requirements or product performance parameters. For example, the first preset speed can be set to 0.1krpm.

[0167] For example, the motor speed of the vacuum cleaner 200 is detected by a Hall effect sensor and converted into a voltage or digital signal. Further, the comparator receives the voltage or digital signal and compares it with the signal corresponding to the second preset speed. If the current speed is less than or equal to the second preset speed, the comparator will output a third drive signal. The third drive signal is given to the PWM generator 14 so that the PWM generator 14 generates a PWM signal. Then, the controller 104 controls the first switching device 11 to be in the off state and controls the second switching device 12 to be in the target state.

[0168] Therefore, when the motor 101 reaches a given low speed or is close to stopping, more precise current control and braking force can be achieved by giving a particularly high PWM duty cycle or by fully turning on the second switching device 12, ensuring that the motor 101 is stopped quickly. Furthermore, at low speeds, by quickly controlling the motor to stop, vibration and noise can be reduced, so that the user cannot hear a noticeable stopping sound, thus improving the user's perception, control, and user experience.

[0169] It should be noted that a particularly high PWM duty cycle means that the signal is at a high level for most of the time during a PWM cycle. During the high level period, the MOSFET is in the on state, while it is in the off state for a small part of the time.

[0170] Furthermore, in this invention, by selecting a suitable target state under different operating conditions, it is possible to flexibly adapt to different braking requirements and load conditions, which helps to improve the stability of the motor braking device 100 and reduce vibration and noise.

[0171] Optionally, when the pulse width modulation signal is used to indicate that the second switching device is in the second state, the pulse width modulation duty cycle is less than a second threshold. The second threshold is used to ensure that a particularly high PWM duty cycle is directly given during braking to achieve rapid and complete braking of the motor.

[0172] For example, the motor braking device can detect the current speed of the motor in real time and compare it with the second preset speed. If the current speed is greater than the second preset speed, the second switching device can be controlled to be in the second state to quickly reduce the motor speed and stop the motor. At this time, the PWM duty cycle used to generate the PWM signal is a particularly high PWM duty cycle, which can provide the maximum braking torque in the shortest time and achieve the effect of quickly stopping the motor.

[0173] Optionally, the controller is used for:

[0174] Based on the detected current speed of the motor, the current speed is compared with the second preset speed;

[0175] When the current rotational speed is determined to be greater than the second preset speed, the motor is controlled to brake.

[0176] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device is controlled to be in the off state and the second switching device is controlled to be in the target state. The target state includes the first state and the second state. The first state is that the second switching device is in the fully on state. The second state is that within a unit cycle, the second switching device is in the on state for a first duration and in the off state for a second duration. The first duration is longer than the second duration.

[0177] When the pulse width modulation signal is used to indicate that the second switching device is in the second state, the pulse width modulation duty cycle is less than the second threshold; the second threshold is greater than the first threshold.

[0178] In this way, by setting different thresholds, the control strategy can be dynamically adjusted according to different working conditions and needs, thereby improving the flexibility and adaptability of the motor braking device. In addition, the setting of the first threshold is to allow the current to be controlled within a safe and adjustable range, while setting the second threshold to be greater than the first threshold allows for a higher duty cycle under specific conditions to achieve rapid and complete braking of the motor, while ensuring that it does not exceed the safe range, thus protecting the safety of the motor and electronic components.

[0179] Optionally, controller 104 is specifically used for:

[0180] When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device 11 is controlled to remain in the off state, and the second switching device 12 is controlled to switch from the switching state to the target state.

[0181] In this invention, after the motor 101 starts braking, the controller 104 can determine the selected braking strategy based on the real-time detected current speed of the motor 101. For example, when the current speed is less than or equal to the first preset speed and greater than the second preset speed, the controller 104 will control the second switching device 12 to be in the on state and the first switching device 11 to remain in the off state, which corresponds to the second braking stage. When the current speed is less than or equal to the second preset speed, the controller 104 will control the first switching device 11 to remain in the off state and control the second switching device 12 to switch from the on state to the target state, which corresponds to the third braking stage.

[0182] For example, such as Figure 7As shown, in the second stage, MOSFETs g1, g3, and g5 receive the pulled-low PWM signal and are in the off state, while MOSFETs g2, g4, and g6 receive the same PWM signal generated based on pulse width modulation and are in the switching state. In the third stage, MOSFETs g1, g3, and g5 continue to receive the pulled-low PWM signal and remain in the off state, while MOSFETs g2, g4, and g6 receive a PWM signal generated with a particularly high PWM duty cycle and switch from the switching state to the target state.

[0183] In this way, the motor braking device 100 can dynamically adjust the braking strategy according to the actual speed to adapt to different operating conditions and needs. Especially at low speeds or near complete stop, by adjusting the state of the second switching device 12, more precise current control and braking force can be achieved, and the braking process can be controlled more stably. This ensures that the motor 101 is brought to a rapid and complete stop while reducing vibration and noise. Through this control strategy, the motor braking device 100 can provide optimized braking performance at low speeds, ensuring the safety, efficiency and reliability of the motor 101.

[0184] In summary, the motor 101 brake adopts a three-stage braking scheme. In the first stage of automatic trolley braking, the controller 104 controls both the first switch device 11 and the second switch device 12 to be in the off state. In the second stage of active braking, the controller 104 controls the second switch device 12 to switch from the off state to the on state, while the first switch device 11 remains in the off state. In the third stage when low speed is reached, the controller 104 controls the first switch device 11 to remain in the off state and controls the second switch device 12 to switch from the on state to the target state.

[0185] It should be noted that at each stage of braking, such as Figure 7 As shown, taking the first switching device 11 as three upper-bridge MOSFETs g1, g3, and g5, and the second switching device 12 as three lower-bridge MOSFETs g2, g4, and g6 as an example, the switching states of the MOSFETs in each switching device can be referred to the description in the above embodiment, and will not be repeated here. The braking effect diagram for each stage can be referred to Figure 9 The resulting image is shown.

[0186] For example, Figure 9 A schematic diagram illustrating the effect of an electric motor brake provided by this utility model, such as... Figure 9 As shown in the diagram, stage A corresponds to the first stage of braking, stage B corresponds to the second stage of braking, and stage C corresponds to the third stage of braking. Figure 9The upper part of the waveform corresponding to serial number 1 shows the change of phase current over time, and the lower part of the waveform corresponding to serial number 2 shows the change of bus current over time. As shown in stage A of the figure, there is no feedback current when motor 101 is naturally sliding. As shown in stage B of the figure, when motor 101 starts to actively brake, the initial current is controlled, and the feedback current is adjusted by using closed-loop control. As shown in stage C of the figure, in the third stage, a large PWM duty cycle or a full braking method with all second switching devices 12 turned on is used. There is a current fluctuation in a very short time, but the braking is completed quickly, thus eliminating the tail noise of motor 101.

[0187] It should also be noted that, through testing and verification, the motor braking device 100 provided by this utility model achieves a stopping speed of less than 500ms, and the user cannot hear a noticeable stopping sound, thus eliminating the long tail sound of the existing vacuum cleaner 200 when it is sliding.

[0188] Optional, such as Figure 1 As shown, the present invention also provides a vacuum cleaner 200, including a motor brake device 100 as described in any of the above embodiments.

[0189] It should be noted that the specific implementation principle and effect of the motor braking device 100 in the vacuum cleaner 200 can be found in the relevant descriptions and effects of the above embodiments, and will not be elaborated further here.

[0190] It should also be noted that, compared with the prior art, this utility model can realize the rapid braking of the motor of the vacuum cleaner 200, which meets the requirement of the vacuum cleaner 200 for rapid motor braking. Furthermore, the vacuum cleaner 200 provided by this utility model can automatically give a suitable initial braking PWM duty cycle according to the current speed when starting to stop braking, and then adjust the feedback current through a closed loop to achieve controllable braking, which greatly improves the application flexibility of the vacuum cleaner 200.

[0191] Optional, such as Figure 2 As shown, this utility model also provides a controller 104, which is electrically connected to the bridge arm structure 102 in the motor braking device 100. The bridge arm structure 102 includes a first switching device 11 and a second switching device 12. The first switching device 11 and the second switching device 12 are electrically connected. The controller 104 is used to control the second switching device 12 to be in the on state and control the first switching device 11 to be in the off state when the motor 101 is braking. When the second switching device 12 is in the on state, the current output by the motor 101 flows back to the power supply battery 103 in the motor braking device 100. The switching state is a state that switches between the on state and the off state based on pulse width modulation within a unit cycle.

[0192] It is understood that the specific implementation principle and effect of the controller 104 can also be found in the relevant descriptions and effects of the above embodiments, and will not be elaborated further here.

[0193] Optionally, the controller 104 can also be implemented in the form of a chip. This utility model does not specifically limit the form of the controller 104.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A motor braking device for a vacuum cleaner, characterized in that, The motor braking device includes a motor, a bridge arm structure, a power supply battery, and a controller; the bridge arm structure includes a first switching device and a second switching device; the first switching device and the second switching device are electrically connected. The power supply battery is electrically connected to the motor through the bridge arm structure, and the controller is electrically connected to the bridge arm structure. The controller is used to control the second switching device to be in the switching state and control the first switching device to be in the off state when the motor is braking, and when the second switching device is in the switching state, the current output by the motor flows back to the power supply battery. The switching state is a state that switches between the on and off states based on pulse width modulation within a unit cycle.

2. The motor braking device according to claim 1, characterized in that, The bridge arm structure is a three-phase inverter, which includes a lower switch and an upper switch of the three-bridge arm. The connection terminals of the lower switch and the upper switch are electrically connected to the motor.

3. The motor braking device according to claim 1, characterized in that, The motor braking device further includes a current detection circuit, which is electrically connected to the bridge arm structure and is used to detect the bus current and / or bridge arm current.

4. The motor braking device according to claim 3, characterized in that, The controller includes a proportional-integral control unit, which implements pulse width modulation based on a closed-loop method to control the magnitude of the bus current and / or the bridge arm current.

5. The motor braking device according to claim 4, characterized in that, The controller further includes a pulse width modulation generator; the proportional-integral control unit is electrically connected to the pulse width modulation generator, the proportional-integral control unit is used to control the pulse width modulation generator to generate a pulse width modulation signal, and the pulse width modulation signal is used to indicate that the first switching device and the second switching device are in a switching state, an on state, or an off state.

6. The motor braking device according to claim 5, characterized in that, The proportional-integral control unit is specifically used for: A pulse width modulation duty cycle is generated based on the detected bus current and / or the arm current, and the pulse width modulation duty cycle is sent to the pulse width modulation generator so that the pulse width modulation generator generates the pulse width modulation signal based on the pulse width modulation duty cycle; Wherein, when the pulse width modulation signal is used to indicate that the second switching device is in a switching state, the pulse width modulation duty cycle is determined by an initial pulse width modulation duty cycle, which is determined based on the initial speed of the motor during braking and the target peak value of the bridge arm current, and the pulse width modulation duty cycle is less than a first threshold.

7. The motor braking device according to claim 3, characterized in that, The current detection circuit includes a first resistor and / or at least one second resistor; one end of the first resistor is electrically connected to the positive terminal of the power supply battery, and the other end of the first resistor is electrically connected to the first switching device; one end of the at least one second resistor is electrically connected to one of the switches of the second switching device, and the other end of the at least one second resistor is electrically connected to the negative terminal of the power supply battery.

8. The motor braking device according to claim 1, characterized in that, The controller is also used for: Based on the detected current rotational speed of the motor, the current rotational speed is compared with a first preset speed; When the current rotational speed is determined to be less than or equal to the first preset speed, the motor is controlled to brake. When it is determined that the current rotational speed is greater than the first preset speed, the first switching device and the second switching device are both controlled to be in the off state until the rotational speed of the motor is less than or equal to the first preset speed.

9. The motor braking device according to claim 8, characterized in that, The controller is specifically used for: When the motor is controlled to start braking, the second switching device is controlled to switch from the off state to the on state, while the first switching device remains in the off state.

10. The motor braking device according to claim 1, characterized in that, The controller is also used for: Based on the detected current speed of the motor, the current speed is compared with a second preset speed; When it is determined that the current rotational speed is greater than the second preset speed, the motor is controlled to brake; When the current rotational speed is determined to be less than or equal to the second preset speed, the first switching device is controlled to be in the off state and the second switching device is controlled to be in the target state. The target state includes a first state and a second state. The first state is that the second switching device is in the fully on state. The second state is that within the unit cycle, the second switching device is in the on state for a first duration and in the off state for a second duration. The first duration is longer than the second duration.

11. The motor braking device according to claim 10, characterized in that, When the pulse width modulation signal is used to indicate that the second switching device is in a second state, the pulse width modulation duty cycle is less than a second threshold.

12. The motor braking device according to claim 6, characterized in that, The controller is used for: Based on the detected current speed of the motor, the current speed is compared with a second preset speed; When it is determined that the current rotational speed is greater than the second preset speed, the motor is controlled to brake; When it is determined that the current rotational speed is less than or equal to the second preset speed, the first switching device is controlled to be in the off state and the second switching device is controlled to be in the target state. The target state includes a first state and a second state. The first state is that the second switching device is in the fully on state. The second state is that within the unit cycle, the second switching device is in the on state for a first duration and in the off state for a second duration. The first duration is longer than the second duration; When the pulse width modulation signal is used to indicate that the second switching device is in a second state, the pulse width modulation duty cycle is less than a second threshold. The second threshold is greater than the first threshold.

13. The motor braking device according to claim 10, characterized in that, The controller is specifically used for: When it is determined that the current rotational speed is less than or equal to the second preset speed, the first switching device is controlled to remain in the off state, and the second switching device is controlled to switch from the switching state to the target state.

14. A vacuum cleaner, characterized in that, Includes the motor braking device as described in any one of claims 1-13.

15. A controller, characterized in that, The controller is electrically connected to the bridge arm structure in the motor braking device, and the bridge arm structure includes a first switching device and a second switching device; the first switching device and the second switching device are electrically connected. The controller is used to control the second switching device to be in the on state and control the first switching device to be in the off state when the motor brakes, and when the second switching device is in the on state, the current output by the motor flows back to the power supply battery in the motor braking device. The switching state is a state that switches between the on and off states based on pulse width modulation within a unit cycle.

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