Range hood control method and device and range hood

Abstract

The invention provides a control method and device of a range hood and the range hood, the range hood comprises a shell, an exhaust fume collecting hood, a driving mechanism and a transmission structure, the exhaust fume collecting hood is driven by the driving mechanism and the transmission structure to do lifting motion relative to the shell, and the motion mode of the transmission structure causes a mechanical gap to exist in the transmission structure; the method comprises the steps that after a descending instruction is received, a driving mechanism is controlled to increase the height of the exhaust fume collecting hood; wherein the lifting height of the exhaust fume collecting hood is the gap value of the mechanical gap; controlling the driving mechanism to reduce the height of the exhaust fume collecting hood at constant speed; when the load torque of the driving mechanism is greater than or equal to a preset threshold value, controlling the driving mechanism to linearly accelerate to a target speed; and when the distance between the exhaust fume collecting hood and the end point is a preset distance, the driving mechanism is controlled to enable the exhaust fume collecting hood to descend in an S-shaped speed curve. By optimizing the control strategy of the driving mechanism, on the premise that extra hardware cost is not increased, abnormal sound generated by mechanical gaps in the descending process of the range hood is effectively eliminated, and the use experience of a user is improved.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, and in particular to a control method, device, and range hood for a range hood. Background Technology

[0002] In the field of kitchen appliances, lift-up range hoods are increasingly widely used. However, during the descent of existing lift-up range hoods, due to the 0.1-0.5mm mechanical clearance in the screw and nut assembly, the smoke hood will momentarily fall freely under the influence of gravity and collide with the working surface of the screw, producing a "clicking" noise with a peak noise level exceeding 45dB, which seriously affects the user experience.

[0003] Currently, traditional solutions to this problem have many shortcomings, such as: 1. Mechanical backlash elimination methods, such as using preload nuts and dampers, can reduce abnormal noise to some extent, but they increase manufacturing costs by more than 20%, and the screw and nut pair will still wear after long-term use, leading to backlash regeneration and recurring abnormal noise; 2. Pure end-of-stroke buffering methods, such as adding shims at the end of the stroke, can only solve the impact problem at the end of the stroke, but cannot eliminate the impact noise caused by backlash in the middle; 3. Constant-speed motor control methods, such as controlling the motor to run at a constant speed, cannot respond to dynamic changes in backlash, resulting in an abnormal noise probability of over 90%. Therefore, a new technical solution is urgently needed to solve the abnormal noise problem of the screw and nut pair. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a control method, device and range hood for a range hood, so as to effectively eliminate the abnormal noise caused by mechanical clearance during the descent of the range hood without increasing the additional hardware cost by optimizing the control strategy of the drive mechanism, thereby improving the user experience.

[0005] In a first aspect, embodiments of the present invention provide a control method for a range hood. The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement mode of the transmission structure results in mechanical clearance. The method includes: upon receiving a descent command, controlling the drive mechanism to raise the height of the smoke collection hood; wherein the height raised by the smoke collection hood is the clearance value of the mechanical clearance; controlling the drive mechanism to uniformly lower the height of the smoke collection hood; when the load torque of the drive mechanism is greater than or equal to a preset threshold, controlling the drive mechanism to linearly accelerate to a target speed; when the smoke collection hood is a preset distance from the endpoint, controlling the drive mechanism to make the smoke collection hood descend in an S-shaped speed curve.

[0006] In an optional embodiment of this application, the step of controlling the drive mechanism to raise the height of the range hood's smoke collection hood includes: controlling the drive mechanism to operate with reverse micro-torque to raise the height of the smoke collection hood; and controlling the drive mechanism to uniformly lower the height of the smoke collection hood includes: controlling the drive mechanism to operate with forward low speed to uniformly lower the height of the smoke collection hood.

[0007] In optional embodiments of this application, the above method further includes: controlling the drive mechanism to reverse backward based on a preset step distance to determine whether the components of the transmission structure are in contact with each other; if the components of the transmission structure are in contact with each other, determining the number of backward steps of the drive mechanism; and determining the clearance value of the mechanical clearance based on the step distance and the number of backward steps.

[0008] In an optional embodiment of this application, the step of determining that the components of the transmission structure are in contact with each other includes: determining whether the encoder is moving or whether the current is greater than or equal to a preset threshold; if the encoder is moving or the current is greater than the preset threshold, determining that the components of the transmission structure are in contact with each other.

[0009] In an optional embodiment of this application, the step of controlling the drive mechanism to reverse backward based on a preset step distance includes: recording the number of times the drive mechanism is used by a counter; if the number of times the drive mechanism is used is greater than or equal to a preset threshold, controlling the drive mechanism to reverse backward based on a preset step distance.

[0010] In an optional embodiment of this application, the preset distance from the smoke hood to the endpoint is calculated using the following formula: L0 = 0.2S + 0.1V 2 / a max Where L0 is the preset distance, S is the total stroke length of the drive mechanism, V is the current descent speed of the drive mechanism, and a max This represents the maximum acceleration of the driving mechanism.

[0011] In an optional embodiment of this application, the drive mechanism is controlled by the following function to cause the smoke hood to descend in an S-shaped speed curve: V(t) = V max •e^(-t 2 / τ); where t is the time from the preset distance between the smoke hood and the endpoint, and V max The starting speed is e, the natural constant is τ, and the preset time constant is τ. The time constant is determined based on the total mass of the smoke hood.

[0012] In an optional embodiment of this application, the method further includes: calculating the remaining distance of the smoke hood from the endpoint using the following formula: ; where s(t) is the remaining distance.

[0013] Secondly, embodiments of the present invention also provide a control device for a range hood. The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement mode of the transmission structure results in mechanical clearance. The device includes: a smoke collection hood height lifting module, used to control the drive mechanism to lift the height of the smoke collection hood after receiving a descent command; wherein the height of the smoke collection hood is the clearance value of the mechanical clearance; a smoke collection hood height lowering module, used to control the drive mechanism to lower the height of the smoke collection hood at a uniform speed; a drive mechanism linear acceleration module, used to control the drive mechanism to linearly accelerate to a target speed when the load torque of the drive mechanism is greater than or equal to a preset threshold; and a smoke collection hood soft landing module, used to control the drive mechanism to make the smoke collection hood descend in an S-shaped speed curve when the smoke collection hood is a preset distance from the endpoint.

[0014] Thirdly, embodiments of the present invention also provide a range hood for performing the above-described range hood control method.

[0015] The embodiments of the present invention bring the following beneficial effects: This invention provides a control method, device, and range hood for a range hood. Upon receiving a descent command, the method controls a drive mechanism to raise the height of the smoke collection hood; the height raised is defined by the mechanical clearance value. The method then controls the drive mechanism to uniformly lower the height of the smoke collection hood. When the load torque of the drive mechanism is greater than or equal to a preset threshold, the drive mechanism linearly accelerates to a target speed. When the smoke collection hood is a preset distance from the endpoint, the drive mechanism lowers the hood in an S-shaped speed curve. This method effectively eliminates abnormal noise caused by mechanical clearance during the descent of the range hood without increasing additional hardware costs by optimizing the drive mechanism control strategy, thus improving the user experience.

[0016] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0017] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention 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. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A flowchart of a control method for a range hood provided in an embodiment of the present invention; Figure 2 A schematic diagram of a control method for a range hood provided in an embodiment of the present invention; Figure 3 A flowchart illustrating another control method for a range hood provided in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating a self-learning of mechanical clearance after power-on, provided as an embodiment of the present invention. Figure 5 This is a schematic diagram illustrating a periodic self-learning of mechanical clearance provided in an embodiment of the present invention; Figure 6 This invention provides a schematic diagram of a range hood system architecture. Figure 7 This is a schematic diagram of the structure of a control device for a range hood provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Currently, traditional solutions for abnormal noise in lead screw and nut assemblies have many shortcomings. For example: 1. Mechanical backlash elimination methods, such as using preloaded nuts and dampers, can reduce noise to some extent, but they increase manufacturing costs by more than 20%, and the lead screw and nut assemblies will still wear down after long-term use, leading to backlash regeneration and recurring noise problems; 2. Pure end-of-stroke buffering methods, such as adding shims at the end of the stroke, only solve the impact problem at the end of the stroke and cannot eliminate the impact noise caused by backlash in the middle; 3. Constant-speed motor control methods, such as controlling the motor to run at a constant speed, cannot respond to dynamic changes in backlash, resulting in a probability of abnormal noise of over 90%. Therefore, a new technical solution is urgently needed to solve the problem of abnormal noise in lead screw and nut assemblies.

[0022] Based on this, the present invention provides a control method, device and range hood for a range hood, specifically involving a soft-start control method for a range hood based on dynamic gap compensation. By optimizing the control strategy of the drive mechanism, the method effectively eliminates abnormal noise caused by mechanical gaps during the descent of the range hood without increasing additional hardware costs, thereby improving the user experience.

[0023] To facilitate understanding of this embodiment, a control method for a range hood disclosed in this embodiment of the invention will first be described in detail.

[0024] Example 1: This invention provides a control method for a range hood. The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement mode of the transmission structure results in mechanical backlash. For example, the drive mechanism of the range hood may include a motor, and the transmission structure may include a lead screw and nut pair. The movement mode of the lead screw and nut pair during the descent of the smoke collection hood results in mechanical backlash.

[0025] Based on the above description, see Figure 1 The flowchart shown illustrates a control method for a range hood, which includes the following steps: Step S102: After receiving the descent command, control the drive mechanism to raise the height of the smoke collection hood; wherein the height raised by the smoke collection hood is the clearance value of the mechanical clearance.

[0026] During the pre-tightening stage (eliminating gaps), upon receiving a descent command, the drive mechanism of the range hood is controlled to raise the height of the smoke collection hood. The height raised by the smoke collection hood is equal to the gap value of the mechanical clearance, thereby eliminating the mechanical clearance.

[0027] In some embodiments, the drive mechanism can be controlled to operate with reverse micro-torque to increase the height of the smoke hood.

[0028] In this embodiment, the drive mechanism can first operate with reverse micro-torque to raise the height of the smoke hood by 0.05-0.2mm (i.e., the mechanical clearance value is 0.05-0.2mm), thereby eliminating the mechanical clearance.

[0029] See Figure 2 The diagram shows a control method for a range hood. The drive mechanism operates with reverse micro-torque, and the reverse rotation time is t1, which raises the smoke collection hood by 0.1mm and eliminates mechanical clearance.

[0030] Step S104: Control the drive mechanism to lower the height of the smoke hood at a uniform speed.

[0031] After controlling the drive mechanism of the range hood to operate with reverse micro-torque to raise the height of the smoke collection hood, the drive mechanism can also be controlled to lower the height of the smoke collection hood at a uniform speed.

[0032] In some embodiments, the drive mechanism can be controlled to run at a low forward speed to uniformly lower the height of the smoke hood.

[0033] This includes the ability to control the drive mechanism to operate at a low forward speed of 5%-10% of its rated speed. For example... Figure 2As shown, the drive mechanism operates at a low forward speed V1, where V1 is the rated maximum speed V. max 5%.

[0034] Step S106: When the load torque of the drive mechanism is greater than or equal to a preset threshold, control the drive mechanism to accelerate linearly to the target speed.

[0035] During the buffer phase (anti-shock descent), the load torque of the drive mechanism can be detected in real time. When the load torque suddenly increases to a value greater than or equal to a preset threshold, it indicates that the mechanical backlash has been eliminated. At this time, the drive mechanism can be controlled to accelerate linearly to the target speed.

[0036] like Figure 2 As shown, the load torque change ΔT of the drive mechanism is monitored in real time. When ΔT ≥ threshold Tx, it is determined that a gap has been detected and the impact is eliminated. Linear acceleration is initiated, accelerating to the target speed Vx at a slope of k = 0.2V / s.

[0037] Step S108: When the smoke hood is at a preset distance from the endpoint, control the drive mechanism to make the smoke hood descend in an S-shaped speed curve.

[0038] like Figure 2 As shown, after the drive mechanism accelerates linearly to the target speed, when the smoke hood is a preset distance L0 from the endpoint (also known as the end point), the drive mechanism can be controlled to make the smoke hood descend in an S-shaped speed curve, thereby achieving a soft landing.

[0039] This embodiment can digitize mechanical backlash into a controllable sequence of drive mechanism movements, achieving efficient backlash compensation and noise reduction without the need for additional hardware.

[0040] This invention provides a control method for a range hood. Upon receiving a descent command, the method controls a drive mechanism to raise the height of the smoke collection hood, wherein the height raised is equal to the mechanical clearance value. The method then controls the drive mechanism to uniformly lower the height of the smoke collection hood. When the load torque of the drive mechanism is greater than or equal to a preset threshold, the drive mechanism linearly accelerates to a target speed. When the smoke collection hood is a preset distance from the endpoint, the drive mechanism lowers the hood in an S-shaped speed curve. This method effectively eliminates abnormal noise caused by mechanical clearance during the descent of the range hood without increasing additional hardware costs by optimizing the drive mechanism control strategy, thus improving the user experience.

[0041] Example 2: This embodiment provides another control method for a range hood, which is implemented based on the above embodiment. It focuses on describing the specific methods of mechanical clearance self-learning and dynamic control of the descent process. (See [link]). Figure 3 The flowchart shown illustrates another control method for a range hood, which includes the following steps: Step S302: Control the drive mechanism to reverse backward based on a preset step distance to determine whether the components of the transmission structure are in contact with each other; if the components of the transmission structure are in contact with each other, determine the number of backward steps of the drive mechanism; determine the clearance value of the mechanical clearance based on the step distance and the number of backward steps.

[0042] This embodiment allows for self-learning of mechanical backlash. Taking a transmission structure component including a lead screw and nut pair as an example, mechanical backlash self-learning can be performed after power-on or periodically. See also Figure 4 The diagram shown illustrates a self-learning mechanism for mechanical backlash after power-on. After power-on, the drive mechanism can be controlled to slowly retract in the opposite direction (retracting only 0.01mm each time, i.e., the step distance is 0.01mm). The drive mechanism can determine whether the lead screw and nut pair are in contact with each other while retracting.

[0043] In some embodiments, it can be determined whether the encoder is moving or whether the current is greater than or equal to a preset threshold; if the encoder is moving or the current is greater than the preset threshold, it is determined that the components of the transmission structure are in contact with each other.

[0044] In this embodiment, two checks can be performed while moving backward: Check 1: Check if the encoder detects movement; Check 2: Check if the current suddenly increases. If either condition is met, the process stops and the number of backward steps (e.g., 20 backward steps) is recorded. The gap value = 20 steps × 0.01 mm = 0.2 mm. The value is stored in the chip's "memory bank", such as EEPROM (Electrically Erasable Programmable Read Only Memory).

[0045]

[0046] Table 1 As shown in Table 1, step distance = lead ÷ (number of steps per revolution of the drive mechanism × differential). Taking a lead of 4mm, a 200-step drive mechanism, and a differential of 16 as an example, the specific calculation process is as follows: Substituting the lead of 4mm, the number of steps per revolution of the drive mechanism of 200, and the differential of 16 into the formula, we can get the step distance = 4 ÷ (200 × 16) = 0.00125mm.

[0047] In some embodiments, a counter can be used to record the number of times the drive mechanism is used; if the number of times the drive mechanism is used is greater than or equal to a preset threshold, the drive mechanism is controlled to reverse backward based on a preset step distance.

[0048] After prolonged use, the lead screw and threads of the drive mechanism wear, increasing the clearance and requiring re-learning of the clearance. (See also...) Figure 5The diagram illustrates a periodic self-learning process for mechanical backlash, where the number of uses recorded by the counter is greater than or equal to a threshold. Figure 5 If the threshold is 1000, then the drive mechanism needs to be controlled to reverse backward based on the preset step distance to perform mechanical backlash self-learning.

[0049] This embodiment addresses the issue of increased clearance caused by long-term use of the lead screw (e.g., from 0.05mm to 0.2mm) by periodically learning and updating the clearance value, thus automatically compensating for wear. This embodiment employs a dual-verification mechanism based on displacement and current surges, avoiding false triggering (traditional solutions have a single-condition false judgment rate >30%). This embodiment utilizes existing encoders and current sensors, achieving zero hardware cost without requiring additional dampers / preload nuts. This embodiment can also actively fill mechanical clearances, eliminate free fall, and prevent gravitational impacts.

[0050] Step S304: After receiving the descent command, control the drive mechanism to raise the height of the smoke hood.

[0051] Step S306: Control the drive mechanism to lower the height of the smoke hood at a uniform speed.

[0052] Step S308: When the load torque of the drive mechanism is greater than or equal to a preset threshold, control the drive mechanism to accelerate linearly to the target speed.

[0053] Step S310: When the smoke hood is at a preset distance from the endpoint, control the drive mechanism to make the smoke hood descend in an S-shaped speed curve.

[0054] This embodiment also provides a dynamic control mechanism for the descent process: if the acceleration or speed of the drive mechanism is too large when it stops in the lowered position, it will damage the screw and threads. In order to achieve a smooth stop with zero impact within a limited distance, this embodiment proposes an S-shaped speed curve to achieve a soft landing. The S-curve is essentially a speed planning curve with continuously changing acceleration. By defining the functional relationship between acceleration, speed and displacement in segments, the acceleration of the equipment is not abrupt (avoiding impact and vibration) during the process of "start-up → acceleration → constant speed → deceleration → stop", while taking into account motion efficiency (more suitable for complex scenarios than pure constant speed / trapezoidal curve).

[0055] In some embodiments, the preset distance from the smoke hood to the endpoint can be calculated using the following formula: L0 = 0.2S + 0.1V 2 / a max Where L0 is the preset distance, S is the total stroke length of the drive mechanism, V is the current descent speed of the drive mechanism, and a max This represents the maximum acceleration of the driving mechanism.

[0056] This embodiment can dynamically calculate the deceleration trigger point: L0 = 0.2S + 0.1V 2 / a max Of these, 0.2S is the basic safety distance (to prevent position detection errors); 0.1V 2 / a max For dynamic adjustment items (the higher the current speed, the greater the lead time), the meaning of each symbol can be seen in Table 2.

[0057]

[0058] Table 2 For example, if S = 380 mm, v = 20 mm / s, a max =0.5m / s 2 Then the distance at which deceleration begins is L0 = 0.2 × 380 + 0.1 × 20. 2 / 500=76.08mm.

[0059] In some embodiments, the drive mechanism can be controlled by the following function to enable the smoke hood to soft-land with an S-shaped velocity curve: V(t) = V max •e^(-t 2 / τ); where t is the time from the preset distance between the smoke hood and the endpoint, and V max The starting speed is e, the natural constant is τ, and the preset time constant is τ. The time constant is determined based on the total mass of the smoke hood.

[0060] In this embodiment, an S-shaped velocity curve V(t) = V can be generated. max •e^(-t 2 / τ). The S-shaped velocity curve has the following characteristics: t=0 (trigger point): V=V max As t increases: the velocity decreases exponentially; as t→∞: V→0 (theoretical value).

[0061] The adaptive calculation formula for the time constant τ can be: τ=0.3×(m / 5)1 / 2, and the meaning of each symbol can be shown in Table 3. Examples of adaptive effects can be shown in Table 4.

[0062]

[0063] Table 3

[0064] Table 4 In some embodiments, the remaining distance from the smoke hood to the endpoint can also be calculated using the following formula: ; where s(t) is the remaining distance.

[0065] The remaining distance mentioned above can For velocity integrals (from time t to infinity), numerical computation or the use of an error function is required. Velocity integrals can involve error functions; in this example, numerical integration can be used.

[0066] The dynamic control mechanism for the descent process in this embodiment allows for continuous variation of acceleration (traditional trapezoidal curve impact force > 5N → S-curve < 0.5N), exhibiting zero-impact stop characteristics. The τ value can be dynamically adjusted according to the mass, adapting to different weights and thus self-adapting to the load.

[0067] For example, suppose V max =20mm / s, S=380mm, m=10kg, preset τ=0.3s, a max =0.5m / s 2 .

[0068] 1. Calculate the deceleration trigger point L0 = 0.2 × 380 + 0.1 × 20 2 / 500=76.08mm. When deceleration is triggered, the remaining distance is 76.08mm (distance from the endpoint).

[0069] 2. Calculate the deceleration time constant τ = 0.3 × (10 / 5)¹ / ² = 0.424 s.

[0070] 3. Generate an S-shaped velocity curve and motion process: V(t) = 20•e^(-t) 2 / 0.424); The remaining distance s(t) is calculated numerically based on L0=76.08mm minus the displacement integral. The motion process data table is shown in Table 5.

[0071]

[0072] Table 5 See Figure 6 The diagram shows a system architecture of a range hood. The operating logic in this embodiment is as follows: 1. Initialization and parameter reading: After the system starts, the MCU (microcontroller unit) reads the gap value and other initialization parameters from the EEPROM (electrically erasable programmable read-only memory). These parameters are used for the relevant calculations and adjustments of the subsequent drive mechanism control.

[0073] 2. Position signal acquisition: The encoder collects the position information of the drive mechanism in real time and transmits the position signal to the MCU so that the MCU knows the current position status of the drive mechanism.

[0074] 3. Control Signal Output: Based on its internally preset control logic, the MCU generates a corresponding PWM (Pulse Width Modulation) signal by combining the received position signal and parameters read from the EEPROM. Parameters such as the duty cycle of the PWM signal determine the operating status of the drive mechanism, such as speed and direction, and this signal is then sent to the driver.

[0075] 4. Drive mechanism drive: After receiving the PWM signal from the MCU, the driver amplifies and processes it, and outputs a suitable drive signal to control the operation of the drive mechanism, so that the drive mechanism works in accordance with the mode set by the PWM signal.

[0076] 5. Current Feedback: During operation, the sampling circuit collects the operating current of the drive mechanism. The analog current signal is converted into a digital signal by an ADC (Analog-to-Digital Converter) and fed back to the MCU. Based on this feedback, the MCU further adjusts the PWM signal to achieve precise control of the drive mechanism, such as overcurrent protection and current loop control, ensuring stable and reliable operation. The entire process forms a closed-loop control system with continuous dynamic adjustments, guaranteeing precise operation of the drive mechanism as required.

[0077] The method described in this invention provides a gap self-learning system that automatically performs reverse micro-stepping upon power-up. It determines the contact point using both displacement and current change rate, calculates and stores the gap value, and refreshes the system every 1000 cycles. This automatically compensates for gap increases caused by wear, eliminates the "clunking" noise caused by gaps, and requires no manual maintenance.

[0078] The method provided in this embodiment of the invention provides an adaptive S-shaped speed planning method for dynamically calculating the deceleration trigger point, which can achieve zero-impact soft landing, automatically adapt to different loads, and eliminate end-stage vibration.

[0079] The method provided in this embodiment of the invention also provides a closed-loop linkage mechanism of a triple collaborative control architecture: preload compensation (eliminating gaps) → torque detection (triggering acceleration) → S-curve buffering (smooth stopping). This mechanism can reduce mechanical impact energy by 95%, solve the problem of abnormal noise throughout the stroke, and extend the mechanical life.

[0080] Example 3: Corresponding to the above method embodiments, this invention provides a control device for a range hood. The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement mode of the transmission structure results in mechanical backlash. See [link to relevant documentation]. Figure 7 The diagram shows a structural schematic of a control device for a range hood. The control device includes: The smoke hood height lifting module 71 is used to control the drive mechanism to lift the height of the smoke hood after receiving a descent command; wherein the height of the smoke hood is lifted is the clearance value of the mechanical clearance. The smoke hood height reduction module 72 is used to control the drive mechanism to uniformly reduce the height of the smoke hood. The linear acceleration module 73 of the drive mechanism is used to control the drive mechanism to accelerate linearly to the target speed when the load torque of the drive mechanism is greater than or equal to a preset threshold. The smoke hood soft landing module 74 is used to control the drive mechanism to make the smoke hood descend in an S-shaped speed curve when the smoke hood is at a preset distance from the endpoint.

[0081] This invention provides a control device for a range hood. Upon receiving a descent command, the device controls a drive mechanism to raise the height of the smoke collection hood, wherein the height raised is equal to the mechanical clearance value. The drive mechanism is then controlled to uniformly lower the height of the smoke collection hood. When the load torque of the drive mechanism is greater than or equal to a preset threshold, the drive mechanism linearly accelerates to a target speed. When the smoke collection hood is a preset distance from the endpoint, the drive mechanism lowers the hood in an S-shaped speed curve. This method effectively eliminates abnormal noise caused by mechanical clearance during the descent of the range hood without increasing additional hardware costs by optimizing the drive mechanism control strategy, thus improving the user experience.

[0082] The aforementioned smoke hood height lifting module is used to control the drive mechanism to operate with reverse micro-torque to raise the height of the smoke hood; the aforementioned smoke hood height lowering module is used to control the drive mechanism to operate at a forward low speed to uniformly lower the height of the smoke hood.

[0083] The aforementioned device further includes: a clearance self-learning module, used to control the drive mechanism to reverse backward based on a preset step distance, determine whether the components of the transmission structure are in contact with each other; if the components of the transmission structure are in contact with each other, determine the number of backward steps of the drive mechanism; and determine the clearance value of the mechanical clearance based on the step distance and the number of backward steps.

[0084] The aforementioned gap self-learning module is used to determine whether the encoder has moved or whether the current is greater than or equal to a preset threshold; if the encoder has moved or the current is greater than the preset threshold, it determines that the components of the transmission structure are in contact with each other.

[0085] The aforementioned gap self-learning module is used to record the number of times the drive mechanism is used through a counter; if the number of times the drive mechanism is used is greater than or equal to a preset threshold, the drive mechanism is controlled to reverse backward based on a preset step distance.

[0086] The aforementioned smoke hood soft landing module is used to calculate the preset distance between the smoke hood and the endpoint using the following formula: L0 = 0.2S + 0.1V 2 / a maxWhere L0 is the preset distance, S is the total stroke length of the drive mechanism, V is the current descent speed of the drive mechanism, and a max This represents the maximum acceleration of the driving mechanism.

[0087] The aforementioned smoke hood soft landing module is used to control the drive mechanism to achieve a soft landing of the smoke hood with an S-shaped velocity curve through the following function: V(t) = V max •e^(-t 2 / τ); where t is the time from the preset distance between the smoke hood and the endpoint, and V max The starting speed is e, the natural constant is τ, and the preset time constant is τ. The time constant is determined based on the total mass of the smoke hood.

[0088] The aforementioned smoke hood soft landing module is also used to calculate the remaining distance of the smoke hood from the endpoint using the following formula: ; where s(t) is the remaining distance.

[0089] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the control device of the range hood described above can be referred to the corresponding process in the embodiments of the control method of the range hood mentioned above, and will not be repeated here.

[0090] Example 4: This invention also provides a range hood and a control method for operating the range hood.

[0091] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the range hood described above can be referred to the corresponding process in the embodiments of the aforementioned range hood control method, and will not be repeated here.

[0092] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0093] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0095] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for a range hood, characterized in that, The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement of the transmission structure results in mechanical backlash. The method includes: Upon receiving a descent command, the drive mechanism is controlled to raise the height of the smoke collection hood; wherein, the height raised by the smoke collection hood is the clearance value of the mechanical clearance; Control the drive mechanism to lower the height of the smoke collection hood at a uniform speed; When the load torque of the drive mechanism is greater than or equal to a preset threshold, the drive mechanism is controlled to accelerate linearly to the target speed. When the smoke hood is at a preset distance from the endpoint, the drive mechanism is controlled to make the smoke hood descend in an S-shaped speed curve.

2. The method according to claim 1, characterized in that, The step of controlling the drive mechanism to raise the height of the smoke collection hood includes: controlling the drive mechanism to operate with reverse micro-torque to raise the height of the smoke collection hood; The step of controlling the drive mechanism to uniformly lower the height of the smoke hood includes: controlling the drive mechanism to run at a low forward speed to uniformly lower the height of the smoke hood.

3. The method according to claim 1, characterized in that, The method further includes: The drive mechanism is controlled to reverse backward based on a preset step distance to determine whether the components of the transmission structure are in contact with each other; If the components of the transmission structure are in contact with each other, determine the number of backward steps of the drive mechanism; The clearance value of the mechanical clearance is determined based on the step distance and the number of backward steps.

4. The method according to claim 3, characterized in that, The step of determining whether the components of the transmission structure are in contact with each other includes: Determine whether the encoder is moving or whether the current is greater than or equal to a preset threshold; If the encoder moves or the current exceeds a preset threshold, it is determined that the components of the transmission structure are in contact with each other.

5. The method according to claim 3, characterized in that, The step of controlling the drive mechanism to reverse backward based on a preset step distance includes: The number of times the drive mechanism is used is recorded by a counter; If the number of times the drive mechanism is used is greater than or equal to a preset threshold, the drive mechanism is controlled to reverse backward based on a preset step distance.

6. The method according to claim 1, characterized in that, The preset distance between the smoke hood and the endpoint is calculated using the following formula: L0 = 0.2S + 0.1V 2 / a max Where L0 is the preset distance, S is the total stroke length of the drive mechanism, V is the current descent speed of the drive mechanism, and a max This is the maximum acceleration of the drive mechanism.

7. The method according to claim 6, characterized in that, The drive mechanism is controlled by the following function to cause the smoke hood to descend in an S-shaped speed curve: V(t) = V max •e^(-t 2 / τ); where t is the time starting from the preset distance from the end point of the smoke collection hood, and V max The starting speed is e, a natural constant, and τ is a preset time constant; the time constant is determined based on the total mass of the smoke hood.

8. The method according to claim 7, characterized in that, The method further includes: The remaining distance between the smoke hood and the endpoint is calculated using the following formula: Where s(t) is the remaining distance.

9. A control device for a range hood, characterized in that, The range hood includes a housing, a smoke collection hood, a drive mechanism, and a transmission structure. The smoke collection hood moves up and down relative to the housing under the drive of the drive mechanism and the transmission structure. The movement of the transmission structure results in mechanical backlash. The device includes: The smoke hood height lifting module is used to control the drive mechanism to lift the height of the smoke hood after receiving a descent command; wherein the height of the smoke hood is lifted is the clearance value of the mechanical clearance; A smoke hood height reduction module is used to control the drive mechanism to uniformly reduce the height of the smoke hood; A linear acceleration module for a drive mechanism is used to control the drive mechanism to linearly accelerate to a target speed when the load torque of the drive mechanism is greater than or equal to a preset threshold. The smoke hood soft landing module is used to control the drive mechanism to make the smoke hood descend in an S-shaped speed curve when the smoke hood is a preset distance from the endpoint.

10. A range hood, characterized in that, The control method for performing the range hood according to any one of claims 1-8.

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