Particle gridiron temperature control system and method based on periodic feeding and PID control

Abstract

The invention discloses a particle gridiron temperature control system and method based on periodic feeding and PID (Proportion Integration Differentiation) control, and belongs to the technical field of ovens. The continuous control quantity is converted into accurate control over the running time of a feeding motor in a fixed total feeding period, that is, the motor is controlled to run for t time and then stop for T-t time, and therefore dynamic matching of the feeding quantity and the combustion requirement is achieved; a specific control theory and particle combustion characteristics are deeply combined, rapid and accurate adjustment of the temperature of the grill is achieved, meanwhile, the combustion efficiency is remarkably improved, and the energy-saving effect is outstanding.

Description

Technical Field

[0001] This invention relates to the field of barbecue grill technology, and in particular to a temperature control system and method for a pellet grill based on periodic feeding and PID control. Background Technology

[0002] Traditional pellet fuel ovens rely heavily on simple on / off or proportional control for temperature control. This involves detecting the oven temperature and activating the feeding motor to continuously feed pellets when the temperature falls below a set value, stopping feeding once the set temperature is reached. This method has several significant drawbacks:

[0003] First, because the combustion of pellet fuel has significant inertia and hysteresis, simple on / off control can easily lead to large temperature fluctuations (e.g., Figure 2 As shown in the figure, the vertical axis represents temperature and the horizontal axis represents time. Overshoot or undershoot occurs, resulting in poor temperature control accuracy. Temperature stability is even more difficult to guarantee when the cooking chamber area is small (such as less than 600 square inches).

[0004] Secondly, continuous feeding can easily lead to fuel accumulation in the combustion chamber, excessive ignition volume, resulting in excessively strong flames and incomplete fuel combustion in a short period of time. This not only produces a large amount of smoke that affects the flavor of the food, but also leads to low thermal energy utilization, high consumption of pellet fuel, and insufficient energy conservation.

[0005] To improve combustion efficiency, some improvements focus on optimizing the combustion chamber structure. For example, prior art (2025224437254) provides a pellet combustion structure for a grill, which uses an adjustable-speed motor in conjunction with a feeding screw to regulate the feed rate and features a combustion plate with a concave arc and tilt angle, supplemented by an adjustable-speed fan, designed to promote uniform fuel distribution, complete combustion, and easy ash removal. This structure alleviates the problems of fuel accumulation and incomplete combustion to some extent.

[0006] However, this structural design still requires a highly efficient and precise control scheme to translate its hardware advantages into stable and energy-saving temperature control performance. Using only traditional temperature control methods cannot fundamentally solve the problem of temperature overshoot and fluctuations caused by combustion inertia, and the synergy between material feeding and oxygen supply is also difficult to optimize, limiting the full realization of its energy-saving potential.

[0007] Therefore, this invention aims to further introduce advanced control algorithms based on the above-mentioned optimized hardware structure, and propose a hardware and software collaborative solution to completely overcome the technical bottlenecks of inaccurate temperature control and high energy consumption in traditional particle grills. Summary of the Invention

[0008] The purpose of this invention is to provide a temperature control system and method for a pellet oven based on periodic feeding and PID control, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: applied to a combustion chamber comprising a feeding motor, a first temperature sensor, and a grill; including the following steps:

[0010] Temperature setting and sampling steps: Obtain the target temperature value set by the user, and collect the actual temperature inside the grill through the first temperature sensor according to the preset sampling period;

[0011] Incremental PID calculation steps: Based on the target temperature value and the actual temperature value, the incremental PID control algorithm is used to calculate the feeding control quantity within the current control cycle. The calculation formula for the incremental PID control algorithm is as follows:

[0012] Δu(k)=Kp[e(k)-e(k-1)]+Kie(k)+Kd[e(k)-2e(k-1)+e(k-2)];

[0013] Where Δu(k) is the feeding control quantity of the current control cycle, e(k), e(k-1), and e(k-2) are the temperature deviations at the current time, the previous time, and the two previous times, respectively, and Kp, Ki, and Kd are the preset proportional, integral, and derivative coefficients;

[0014] Periodic feeding execution steps: Based on the calculated feeding control quantity Δu(k), within a fixed total feeding cycle T, the feeding motor is controlled to run for time t and then stop for time Tt, where the running time t is positively correlated with the feeding control quantity Δu(k).

[0015] The pellet grill temperature control method based on periodic feeding and PID control of the present invention, wherein in the periodic feeding execution step, the speed of the feeding motor is controlled by a PWM signal, and the duty cycle of the PWM signal is set according to the feeding control quantity Δu(k) or a preset combustion efficiency optimization value.

[0016] The temperature control method for a pellet oven based on periodic feeding and PID control described in this invention, wherein the total feeding period T ranges from 20 seconds to 30 seconds.

[0017] The pellet grill temperature control method based on periodic feeding and PID control of the present invention wherein the values ​​of the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd are obtained by tuning through the following steps: multiple temperature measuring points are arranged in the combustion chamber, the pellet grill is run with target temperature values ​​at multiple levels, the temperature change curves are recorded, and Kp, Ki, and Kd are iteratively adjusted according to the overshoot, steady-state error, and settling time of the temperature curves at each level.

[0018] The temperature control method for a pellet oven based on periodic feeding and PID control described in this invention, wherein the preset sampling period is 1 second.

[0019] Furthermore, the present invention also provides a particle grill temperature control system for performing the above-described temperature control method. The system includes:

[0020] The temperature acquisition module is used to collect the actual temperature inside the grill according to a preset sampling period.

[0021] The controller, connected to the temperature acquisition module, has the incremental PID control algorithm built in, which is used to calculate the feeding control quantity based on the target temperature and the actual temperature, and generate the corresponding control signal.

[0022] A feeding execution module, connected to the controller, includes a feeding motor and is used to execute the periodic feeding action according to the control signal.

[0023] The pellet grill temperature control system based on periodic feeding and PID control of the present invention includes a feeding execution module that further includes a feeding screw connected to the feeding motor and a feeding pipe for accommodating the feeding screw; the feeding pipe is connected to the combustion chamber.

[0024] The pellet oven temperature control system based on periodic feeding and PID control of the present invention includes an inclined combustion plate in the combustion chamber. The combustion plate is concave arc-shaped and has multiple ventilation holes and ash collection holes.

[0025] The pellet oven temperature control system based on periodic feeding and PID control of the present invention further includes an air supply mechanism, which is an adjustable speed fan electrically connected to the controller; the controller is further configured to synchronously adjust the speed of the adjustable speed fan according to the feeding control amount or the actual temperature.

[0026] The pellet oven temperature control system based on periodic feeding and PID control of the present invention further includes a controller configured to maintain the actual temperature fluctuating within ±3°C of the target temperature value after the actual temperature reaches the target temperature value.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] By using an incremental PID algorithm, advanced and precise predictive control of the pellet combustion process, which has large inertia and hysteresis, is achieved, overcoming the problem of large temperature fluctuations caused by traditional on / off control in principle. Moreover, the continuous control output (Δu(k)) of the PID is converted into periodic start-stop execution logic, which is adapted to the characteristics of pellet fuel accumulation-combustion. This avoids incomplete combustion caused by continuous feeding and prevents wear and tear on the motor caused by frequent start-stop, achieving the dual goals of high-precision temperature control and improved combustion efficiency. Attached Figure Description

[0029] 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.

[0030] Figure 1 The simulation results of the method provided by this invention are shown in the graph.

[0031] Figure 2 The graph shows the effect of simulation performed using traditional methods of existing technology.

[0032] Figure 3 This invention describes the complete process from temperature detection to motor control.

[0033] Figure 4 This is an overall structural diagram of the present invention.

[0034] Figure 5 for Figure 4 Structure diagram after the middle diffuser plate is removed.

[0035] Figure 6 This is a longitudinal sectional view of the overall structure of the present invention along the left-right direction.

[0036] Figure 7 for Figure 6 Enlarged view of a local structure.

[0037] Figure 8 for Figure 7 Enlarged view of local structure in Detailed Implementation

[0038] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0041] Furthermore, the terms indicating orientation, such as "up," "down," "left," "right," "upper end," "lower end," and "longitudinal," are all based on the posture and position of the device or equipment described in this solution during normal use.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0043] This embodiment discloses, as follows: Figure 1 and 3 The temperature control method for a pellet grill based on periodic feeding and PID control is applied to a feeding motor 10, a first temperature sensor (not shown), a combustion chamber 20, and a grill 30. The grill 30 is a box structure with a supporting base, and its side wall has an openable door. The inner cavity of the box structure is a chamber for baking food, and the first temperature sensor is placed in the chamber. The combustion chamber is also located at the bottom of the chamber.

[0044] The method described in this solution includes the following steps:

[0045] Temperature setting and sampling steps: Obtain the target temperature value set by the user, and collect the actual temperature inside the grill 30 through the first temperature sensor according to the preset sampling period;

[0046] Incremental PID calculation steps: Based on the target temperature value and the actual temperature value, the incremental PID control algorithm is used to calculate the feeding control quantity within the current control cycle. The calculation formula for the incremental PID control algorithm is as follows:

[0047] Δu(k)=Kp[e(k)-e(k-1)]+Kie(k)+Kd[e(k)-2e(k-1)+e(k-2)];

[0048] Where Δu(k) is the feeding control quantity of the current control cycle, e(k), e(k-1), and e(k-2) are the temperature deviations at the current time, the previous time, and the two previous times, respectively, and Kp, Ki, and Kd are the preset proportional, integral, and derivative coefficients;

[0049] Periodic feeding execution steps: Based on the calculated feeding control quantity Δu(k), within a fixed total feeding cycle T, control the feeding motor 10 to run for t time and then stop for Tt time, where the running time t is positively correlated with the feeding control quantity Δu(k).

[0050] By using an incremental PID algorithm, advanced and precise predictive control of the pellet combustion process, which has large inertia and hysteresis, is achieved, overcoming the problem of large temperature fluctuations caused by traditional on / off control in principle. Moreover, the continuous control output (Δu(k)) of the PID is converted into periodic start-stop execution logic, which is adapted to the characteristics of pellet fuel accumulation-combustion. This avoids incomplete combustion caused by continuous feeding and prevents wear and tear on the motor caused by frequent start-stop, achieving the dual goals of high-precision temperature control and improved combustion efficiency.

[0051] In this embodiment, during the periodic feeding execution step, the rotational speed of the feeding motor 10 is controlled by a PWM signal. The duty cycle of the PWM signal is set according to the feeding control quantity Δu(k) or a preset combustion efficiency optimization value. By introducing PWM control of the motor speed on the basis of periodic feeding, this principle adds fine control of the energy input rate dimension in the time dimension control, so that the feeding process can not only be "quantitative" (running time) but also "speed-controlled" (PWM duty cycle), thereby ensuring that the particles are pushed smoothly and evenly, avoiding local accumulation and oxygen deficiency caused by excessively fast instantaneous feeding, further refining the combustion conditions, and optimizing the fullness and stability of combustion.

[0052] In this embodiment, the total feeding cycle T ranges from 20 to 30 seconds. This time range is the best practice window obtained through experiments. If the cycle is too short (<20 seconds), the motor will start and stop too frequently, affecting its lifespan and causing unstable combustion. If the cycle is too long (>30 seconds), the amount of material fed at one time may be too much, leading to a return to the old path of accumulating combustion. This limitation ensures that the system operates at the optimal rhythm and is a key parameter supporting the achievement of stable temperature control.

[0053] In this embodiment, the values ​​of proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd are obtained through the following steps: multiple temperature measuring points are arranged in the combustion chamber 20, the grill 30 is run at multiple target temperature levels, the temperature change curves are recorded, and Kp, Ki, and Kd are iteratively adjusted according to the overshoot, steady-state error, and settling time of the temperature curves at each level; the PID parameters (Kp, Ki, Kd) are tuned through experimental testing and temperature curve analysis to customize the grill 30 structure, the thermodynamic characteristics of the combustion chamber 20, and the particulate fuel properties of this solution, ensuring the optimal control performance of this method in this specific application scenario (such as small overshoot and fast steady-state).

[0054] In this embodiment, the preset sampling period is 1 second. This sampling period is the optimal monitoring frequency set for the relatively slow temperature change of the grill 30. It can quickly capture the temperature change trend, enabling the PID controller to respond in a timely manner, while avoiding unnecessary computational burden and cost to the controller due to excessively high sampling frequency, thus achieving the goal of balancing response speed and system load.

[0055] Example 2

[0056] This embodiment is basically the same as Embodiment 1, and the similarities will not be repeated. The differences are as follows: Figures 4 to 8 As shown, this embodiment also provides a temperature control system for a pellet oven for executing the temperature control method of Embodiment 1. The system includes a temperature acquisition module, a controller, and a feeding execution module. The temperature acquisition module is used to acquire the actual temperature inside the oven 30 according to a preset sampling period. The controller is connected to the temperature acquisition module and has an incremental PID control algorithm built in, and is used to calculate the feeding control quantity and generate the corresponding control signal based on the target temperature and the actual temperature. The feeding execution module is connected to the controller and includes a feeding motor 10, which is used to perform periodic feeding actions according to the control signal.

[0057] In this embodiment, the feeding execution module further includes a feeding screw 40 that is driven and connected to the feeding motor 10, and a feeding pipe 50 that accommodates the feeding screw 40; the feeding pipe 50 is connected to the combustion chamber 20; wherein, the feeding screw 40 is driven and connected to the rotating shaft 101 of the feeding motor 10 through the transmission assembly 60; specifically, the feeding screw 40 includes a horizontal support tube 41 and a feeding spiral blade 42 that is spirally fixed on the support tube 41; the discharge end of the support tube 41 is located inside the feeding spiral blade 42, and the inlet end extends out of the feeding spiral blade 42; after installation, the outer periphery of the feeding spiral blade 42 is close to the inner wall of the feeding pipe 50 and maintains a certain distance, allowing particulate materials to pass through; and at the upper part of one end of the feeding motor 10 of the grill 30 of the feeding pipe 50, there is an inlet 51 and a feeding hopper 70 adapted to the inlet 51.

[0058] Furthermore, the transmission assembly 60 includes a mounting housing 61 installed on the end face of the feed end of the feeding pipe 50, a first drive disk 62 coaxially connected to the shaft 101 of the feeding motor 10, and a second drive disk 63 coaxially connected to the feed end of the feeding pipe 50. Both the first drive disk 62 and the second drive disk 63 are disc structures, and a movable groove 631 adapted to the first drive disk 62 is provided on the side wall of the second drive disk 63 facing the feeding motor 10. After assembly, the distance between the outer side wall of the first drive disk 62 and the inner side wall of the movable groove 631 is between 2-4 mm. The shaft 101 of the feeding motor 10 is axially detachably connected to the first drive disk 62 to facilitate quick installation and disassembly in the later stage.

[0059] Furthermore, the first drive disk 62 is longitudinally rotatably connected to the inner wall of the mounting housing 61 near the feeding motor 10, while the support tube 41 extends coaxially into the mounting housing 61 with the rotating shaft 101 of the feeding motor 10 and is rotatably connected via a longitudinal bearing 4a. A plurality of cylindrical first strong magnets 80 are evenly embedded circumferentially on the outer peripheral sidewall of the first drive disk 62, while a plurality of cylindrical second strong magnets 90 are embedded on the inner peripheral sidewall of the movable groove 631 corresponding to the plurality of first strong magnets 80. The radially opposite first and second strong magnets have opposite magnetic poles at their proximal ends. After assembly, the gap between the two is between 1-3mm (preferably 1mm); when the feeding motor 10 starts, it drives the first drive disk 62 to rotate and drives the second drive disk 63 to rotate through the magnetic force of multiple first strong magnets 80 and second strong magnets 90, thereby realizing the rotation drive of the feeding spiral blade 42 to push the material forward into the combustion chamber 20; this design can directly avoid the direct connection between the feeding pipe 50 and the rotating shaft 101 of the feeding motor 10 through magnetic transmission, and avoid the heat on the support pipe 41 and the feeding spiral blade 42 from being transferred to the motor and affecting the operation of its internal components.

[0060] Furthermore, to ensure more stable material feeding and sufficient thrust, multiple columnar third strong magnets 100 are coaxially and evenly embedded on the side wall of the first drive disk 62 away from the feeding motor 10. On the inner wall of the movable groove 631, multiple fourth strong magnets 110 are embedded corresponding to the multiple third strong magnets 100. The distance between the third strong magnets 100 and the fourth strong magnets 110 is also maintained between 1-3mm. This design can further increase the upper limit of the torque transmitted by the first drive disk 62 and the second drive disk 63, and can basically avoid the situation where the motor is overloaded due to blockage caused by too much material in the feeding pipe 50.

[0061] In practice, the outer diameter of the second drive disk 63 is 100mm. It uses strong magnets with a diameter of 20mm and a length of 20mm, N35 or higher. The magnets are installed in an alternating N and N pole pattern on the inner and outer circumferences (to ensure a reasonable pitch), and the radial clearance is controlled at about 1mm. Through this series of parameter settings, the magnetic transmission torque can reach more than 5kg / cm, which is sufficient to meet the daily material replenishment requirements.

[0062] In addition, to further reduce the heat transferred from the support tube 41 and the feeding screw 42 to the combustion chamber 20, a through hole 632 directly communicating with the inner cavity of the support tube 41 is provided on the second drive disk 63. The mounting shell 61 is designed as a sealed structure and an air inlet is opened on its side wall to communicate with the external air supply mechanism. When air is blown into the mounting shell, the airflow enters the through hole 632 from the gap between the first drive disk 62 and the movable groove 631 and extends through the support tube 41 to one end of the combustion chamber 20 before being blown out. This not only forms a heat insulation wall between the first drive disk 62 and the second drive disk 63 and cools the feeding screw 42 and the support tube 41, reducing the heat transfer to the feeding motor 10, but also plays a role in providing auxiliary oxygen supply to the combustion chamber 20.

[0063] Furthermore, to ensure the safety of the entire combustion system, multiple second temperature sensors 120 connected to the control system are installed on the outer wall of the feeding pipe 50. When abnormal combustion of material in the feeding pipe 50 is detected, the sensor will promptly report to the system and push the burning material forward through the controller to prevent the material in the fuel hopper 70 from igniting. In addition, the sensor can also be used in conjunction with an audible / visual alarm to alert the user and handle emergencies in a timely manner.

[0064] In this embodiment, the combustion chamber 20 is a barrel-shaped structure with an open top. It has multiple air inlets on its outer side wall and a pipe 130 for installing a high-temperature ignition rod is provided radially at the bottom. An inclined combustion plate 140 is provided inside the combustion chamber 20. The combustion plate 140 is concave arc-shaped and has multiple vent holes and ash collection holes to promote material combustion and facilitate ash collection.

[0065] In this embodiment, an air supply mechanism 150 is also included. The air supply mechanism 150 is an adjustable speed fan and is electrically connected to the controller. The controller is also configured to synchronously adjust the speed of the adjustable speed fan according to the feeding control amount or the actual temperature. In addition, the air supply mechanism mentioned above can also be implemented through the air supply mechanism 150 to reduce the investment in hardware costs.

[0066] Furthermore, to ensure complete combustion of the material inside the combustion chamber 20, the combustion chamber 20 is installed at one end of a horizontal rectangular shell 160, with the outlet exposed above the rectangular shell 160. The feeding pipe 50 is also horizontally placed inside the rectangular shell 160 and has a feed window that communicates with the lower outlet of the hopper 70. After assembly, the feeding pipe 50, the outer wall of the combustion chamber 20, and the inner wall of the rectangular shell 160 together form a sealed air supply chamber 200. The feeding motor 10 is mounted on one end of the rectangular shell 160 via a bracket. The air supply mechanism 150 is located below the rectangular shell 160 and at the end away from the combustion chamber 20, and is connected to the inner cavity of the rectangular shell 160 via a connecting pipe. When the air supply mechanism 150 is activated, it can supply air and oxygen to the combustion chamber 20 through the air supply chamber 200 and the air inlet to ensure complete combustion of the material.

[0067] In this embodiment, the controller of this solution is also configured to maintain the actual temperature within ±3℃ of the target temperature value after the actual temperature reaches the target temperature value, so as to ensure the uniform output of temperature. When the user places the temperature diffuser plate 170 above the combustion chamber 20 for use, the temperature of the diffuser plate 170 can be kept basically constant.

[0068] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A pellet grill temperature control method based on periodic feeding and PID control, applied to a pellet grill comprising a feeding motor, a first temperature sensor, a combustion chamber, and a grill; characterized in that, The method comprises the following steps: temperature setting and sampling: obtaining a target temperature value set by a user, and collecting an actual temperature in the grill through the first temperature sensor at a preset sampling period; incremental PID calculation: calculating a feeding control amount in a current control period based on the target temperature value and the actual temperature value, wherein a calculation formula of the incremental PID control algorithm is as follows: Δu(k)=Kp[e(k)-e(k-1)]+Kie(k)+Kd[e(k)-2e(k-1)+e(k-2)]; wherein Δu(k) is the feeding control amount in the current control period, e(k), e(k-1), and e(k-2) are temperature deviations at the current time, the previous time, and the time two times ago, respectively, and Kp, Ki, and Kd are preset proportional, integral, and differential coefficients; periodic feeding execution: controlling the feeding motor to run for t time and then stop for T-t time in a fixed feeding total period T according to the calculated feeding control amount Δu(k), wherein the running time t is positively correlated with the feeding control amount Δu(k).

2. The pellet grill temperature control method based on periodic feeding and PID control according to claim 1, wherein, In the periodic feeding execution step, the speed of the feeding motor is controlled by a PWM signal, and the duty cycle of the PWM signal is set according to the feeding control amount Δu(k) or a preset combustion efficiency optimization value.

3. The pellet grill temperature control method based on periodic feeding and PID control according to claim 1, wherein, The feeding total period T ranges from 20 seconds to 30 seconds.

4. The pellet grill temperature control method based on periodic feeding and PID control according to claim 1, wherein, The values of the proportional coefficient Kp, the integral coefficient Ki, and the differential coefficient Kd are obtained by the following steps: arranging multiple temperature measuring points in the combustion chamber, operating the pellet grill at multiple target temperature values, recording temperature change curves, and iteratively adjusting Kp, Ki, and Kd according to the overshoot, steady-state error, and regulation time of the temperature curves at each gear.

5. The pellet grill temperature control method based on periodic feeding and PID control according to claim 1, wherein, The preset sampling period is 1 second.

6. A pellet grill temperature control system for performing the temperature control method of any one of claims 1-5, wherein, It comprises: a temperature collection module for collecting an actual temperature in the grill at a preset sampling period; a controller connected to the temperature collection module, which is built-in with the incremental PID control algorithm, and is used for calculating a feeding control amount according to a target temperature and the actual temperature, and generating a corresponding control signal; a feeding execution module connected to the controller, which comprises a feeding motor, and is used for executing the periodic feeding action according to the control signal.

7. The pellet grill temperature control system based on periodic feeding and PID control of claim 6, wherein, The feeding execution module further comprises a feeding screw in transmission connection with the feeding motor, and a feeding pipeline accommodating the feeding screw; the feeding pipeline is in communication with the combustion chamber.

8. The pellet grill temperature control system based on periodic feeding and PID control of claim 7, wherein, The combustion chamber is provided with an inclined combustion plate, which is concave arc-shaped and has multiple air holes and ash holes.

9. The pellet grill temperature control system based on periodic feeding and PID control of claim 8, wherein, It further comprises a blowing mechanism, which is a speed-adjustable fan electrically connected to the controller; the controller is further configured to synchronously adjust the speed of the speed-adjustable fan according to the feeding control amount or the actual temperature.

10. The pellet grill temperature control system based on periodic feeding and PID control of claim 6, wherein, The controller is further configured to maintain the actual temperature within a range of ±3°C of the target temperature value when the actual temperature reaches the target temperature value.

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