An ultra-low temperature refrigerator based on energy-saving control

Abstract

The application relates to the field of energy-saving control of refrigerators, and specifically discloses an ultra-low-temperature refrigerator based on energy-saving control, which comprises an article stacking sensing module, an airflow restriction evaluation module, an initial opening degree setting module and an opening degree redistribution module. The 3D visual sensor is used to scan the articles in front of the air outlet in real time, a three-dimensional point cloud model is established, and the relative distance and angle are obtained; the airflow blockage rate is calculated based on the point cloud data, and the airflow restriction degree is evaluated in combination with a space pose compensation factor; the current air outlet damper opening degree is dynamically adjusted according to the evaluation result, and the opening degrees of the adjacent air outlets are coordinately adjusted to realize air volume distribution; finally, the backflow temperature of the adjacent air outlets is monitored by a temperature sensor, and the closed-loop redistribution of the damper opening degree is carried out. The application can accurately sense the space posture of the articles, scientifically evaluate the airflow obstruction condition, realize the coordinated energy-saving control of multiple air outlets, effectively improve the refrigeration efficiency, reduce the energy consumption, and ensure the uniform and stable temperature in the refrigerator.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refrigerator energy-saving control, and relates to an ultra-low temperature refrigerator based on energy-saving control. BACKGROUND

[0002] With the increasing awareness of energy conservation and environmental protection and the continuous expansion of cold chain logistics demand, ultra-low temperature refrigerators are increasingly widely used in the fields of biological medicine, scientific research, food storage, etc. Ultra-low temperature refrigerators usually use multi-air outlet air supply to achieve uniform cooling, but in actual use, the stacking posture and position of the goods in the refrigerator often block part of the air outlet, causing air supply flow obstruction, local temperature unevenness, and refrigeration efficiency decline, thereby causing energy waste and equipment load increase.

[0003] Some attempts have been made in the prior art to perceive obstacles through sensors and adjust damper opening. For example, a refrigerator with air curtain function is proposed in Chinese Patent No. CN112066616B, which detects whether there is an object (such as a human hand) close to the front area of the door body through an infrared distance sensor, and adjusts the damper opening accordingly to avoid direct blowing of cold air to the user, thereby improving the use comfort. However, this scheme can only perceive two-dimensional distance information, cannot obtain the three-dimensional shape and spatial posture of the goods, cannot quantify the degree of air flow obstruction, and lacks the ability to coordinate and dynamically redistribute multiple air outlets, so there are still problems such as low energy efficiency and insufficient temperature control accuracy in complex stacking scenarios.

[0004] Therefore, there is an urgent need for an ultra-low temperature refrigerator system that can perceive the three-dimensional spatial posture of goods in real time, accurately assess the degree of air flow restriction, and realize coordinated energy-saving control of multiple air outlets. SUMMARY

[0005] To solve the above problems, the present application provides an ultra-low temperature refrigerator based on energy-saving control, which realizes the function of energy-saving control of the refrigerator.

[0006] The technical scheme adopted by the present application to solve its technical problems is: the present application provides an ultra-low temperature refrigerator based on energy-saving control, comprising: an article stacking perception module: a 3D vision sensor is used to scan the articles stacked in the front area of the air outlet in real time, establish a three-dimensional point cloud model of the articles, and obtain the relative distance and relative angle between the articles and the air outlet.

[0007] A gas flow restriction evaluation module: based on the three-dimensional point cloud model, the volume occupancy rate in the conical space in the normal direction of the air outlet is analyzed to calculate the air flow obstruction rate, and the relative distance and relative angle are combined to evaluate the air flow restriction degree of the air outlet.

[0008] The opening degree initial setting module: judging whether to reduce the damper opening degree according to the airflow restriction degree of the air outlet, if yes, determining the reduction amount of the damper opening degree, and analyzing the increase amount of the damper opening degree of each adjacent air outlet of the air outlet, controlling the air volume adjusting device to adjust the damper opening degree, if no, keeping the original damper opening degree.

[0009] The opening degree redistribution module: continuously monitoring the backflow temperature of each adjacent air outlet through the temperature sensor, and redistributing the damper opening degree of each adjacent air outlet based on the difference between the backflow temperature of the adjacent air outlet and the set temperature and the difference between the backflow temperatures of the adjacent air outlets.

[0010] Compared with the prior art, the ultra-low temperature refrigerator based on energy-saving control has the following advantages: 1. Accurate perception of the three-dimensional spatial posture of the object: the 3D vision sensor of the present application scans the area in front of the air outlet in real time, constructs a three-dimensional point cloud model of the object, and calculates the relative distance and angle of the object from the air outlet, providing high-precision spatial data support for subsequent airflow restriction evaluation.

[0011] 2. Scientific evaluation of airflow restriction degree: the present application calculates the airflow obstruction rate based on three-dimensional point cloud data, combines with the spatial pose compensation factor, and comprehensively evaluates the airflow restriction degree of the air outlet, overcoming the limitations of relying only on distance or volume judgment, and being more consistent with the actual airflow organization characteristics.

[0012] 3. Dynamic damper opening degree adjustment and collaborative compensation: the present application dynamically adjusts the damper opening degree of the air outlet according to the airflow restriction degree, and collaboratively adjusts the damper opening degree of the adjacent air outlet of the air outlet, realizes intelligent distribution of air volume, avoids local overcooling or overheating, and improves the overall refrigeration efficiency.

[0013] 4. Temperature feedback closed-loop control: the present application redistributes the damper opening degree of the adjacent air outlet by continuously monitoring the backflow temperature of the adjacent air outlet, ensures the uniformity and stability of the temperature in the cabinet, and further improves the energy efficiency and control accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0015] Figure 1 The system module connection diagram of the present application.

[0016] Figure 2 The relative position diagram of the object and the air outlet of the present application.

[0017] Figure 3The effective air supply cone space of the air outlet of the application is shown in the schematic diagram. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0019] Please refer to Figure 1 The application provides an ultra-low temperature refrigerator based on energy-saving control, which comprises an article stacking sensing module, an airflow restriction evaluation module, an opening degree initial setting module and an opening degree redistribution module.

[0020] The airflow restriction evaluation module is connected with the article stacking sensing module and the opening degree initial setting module, and the opening degree redistribution module is connected with the opening degree initial setting module.

[0021] The article stacking sensing module scans the articles stacked in the region in front of the air outlet in real time through a 3D visual sensor, establishes a three-dimensional point cloud model of the articles, and obtains the relative distance and the relative angle between the articles and the air outlet.

[0022] Further, the specific working process of the article stacking sensing module is as follows: the 3D visual sensor deployed near the air outlet scans the articles stacked in the region in front of the air outlet in real time, and establishes a three-dimensional point cloud model of the articles based on the sensor data.

[0023] Please refer to Figure 2 The center point of the air outlet is made as a normal line of the plane where the center point is located, and is recorded as a reference line, the length of the line segment connecting the center point of the article and the center point of the air outlet is obtained , and the included angle between the line segment and the reference line is obtained . The included angle is recorded as the relative angle between the article and the air outlet.

[0024] The relative distance between the article and the air outlet is calculated by the formula . .

[0025] It should be noted that in the application, the ultra-low temperature refrigerator is uniformly distributed with a plurality of air outlets, and a 3D visual sensor is correspondingly deployed near each air outlet, which is used to collect three-dimensional point cloud data of the articles stacked in the region in front of the air outlet to reconstruct a three-dimensional point cloud model.

[0026] It should be noted that the 3D visual sensor includes but is not limited to a ToF sensor or a structured light camera.

[0027] In the embodiment, the application scans the area in front of the air outlet in real time through a 3D vision sensor, constructs a three-dimensional point cloud model of the object, and calculates the relative distance and angle of the object from the air outlet, thereby providing high-precision spatial data support for subsequent airflow restriction evaluation.

[0028] The airflow restriction evaluation module analyzes the volume occupancy rate in the conical space in the normal direction of the air outlet based on the three-dimensional point cloud model, calculates the airflow obstruction rate, and evaluates the airflow restriction degree of the air outlet in combination with the relative distance and relative angle.

[0029] Further, the specific working process of calculating the airflow obstruction rate in the airflow restriction evaluation module is as follows: Figure 3 Referring to FIG. 1, the effective air supply conical space of the air outlet is constructed with the center point of the air outlet as the vertex and the normal direction of the air outlet as the central axis, and the opening angle and the detection depth of the conical space are determined.

[0030] D2: A three-dimensional coordinate system established with the center point of the 3D vision sensor as the origin is referred to as the sensor coordinate system.

[0031] Based on the three-dimensional point cloud model of the object, the original point cloud data is obtained and preliminary noise reduction processing is performed to obtain the preprocessed point cloud and its three-dimensional coordinates in the sensor coordinate system.

[0032] D3: A three-dimensional coordinate system established with the center point of the air outlet as the origin and the normal direction of the air outlet as the Z-axis is referred to as the air outlet coordinate system.

[0033] D4: The offset parameters of the center point of the 3D vision sensor relative to the center point of the air outlet are measured, including the position offset and the angle offset.

[0034] Based on the offset parameters, a fixed transformation matrix from the sensor coordinate system to the air outlet coordinate system is constructed.

[0035] D5: The three-dimensional coordinates of the preprocessed point cloud in the sensor coordinate system are converted to the air outlet coordinate system by applying the transformation matrix to obtain the converted point cloud data.

[0036] D6: Based on the three-dimensional coordinates of the converted point cloud, the point cloud located in the effective air supply conical space is selected and referred to as the effective space point cloud.

[0037] D7: According to the preset equal volume principle, the effective air supply conical space is divided into a plurality of cubic units, and each unit is referred to as a voxel.

[0038] D8: It is judged whether each voxel contains effective space point cloud: if yes, the voxel is referred to as occupied voxel, otherwise, it is referred to as unoccupied voxel.

[0039] Count the number of occupied voxels and multiply by the volume of a single voxel to get the volume of the effective plenum space occupied by the object .

[0040] D9: Calculate the total volume of the effective plenum cone space using the standard cone volume formula based on the opening angle and the probe depth of the cone .

[0041] D10: Calculate the air flow obstruction rate of the outlet using the formula . .

[0042] Note that the normal direction of the outlet is the main direction of air supply.

[0043] Note that the effective plenum space of the outlet is defined as a cone space because it conforms to the diffusion pattern of cold air after being sent out from the outlet.

[0044] Note that the opening angle corresponds to the thickness of the cone, and the probe depth corresponds to the length of the cone.

[0045] Note that the point cloud is preliminarily denoised to remove obvious isolated outliers in space.

[0046] Note that since the 3D vision sensor is usually installed near the outlet rather than the center, a fixed transformation matrix is needed to convert the three-dimensional coordinates of all point clouds of the object in the sensor coordinate system to the outlet coordinate system, and then to facilitate the judgment of whether each point cloud is located in the effective plenum cone space of the outlet.

[0047] Note that the position offset refers to the distance between the center point of the 3D vision sensor and the center point of the outlet in three directions; the angle offset refers to the angle between the optical axis of the 3D vision sensor and the normal direction of the outlet.

[0048] Note that the voxel is a tiny cubic unit. The size of the voxel determines the accuracy of the calculation. In a specific embodiment, the size of the voxel is 0.5cmx0.5cmx0.5cm.

[0049] Note that if there is at least one effective space point cloud in a voxel, it is considered to be blocked and recorded as an occupied voxel.

[0050] Note that the air flow obstruction rate refers to the ratio of the volume of the object that hinders the air flow organization in front of the outlet to the theoretical effective plenum space volume of the outlet. The value is a scalar between 0 and 1. ​ representing that the front is completely unobstructed, representing that the front is completely blocked.

[0051] It should be noted that in calculating the airflow blockage rate, in addition to selecting the conical space in the normal direction of the air outlet, other specific solid angle spaces such as pyramid space, hemispherical space, self-defined polyhedral space, dynamic space based on velocity threshold, etc. can be selected according to different application scenarios, precision requirements and flow characteristics.

[0052] It should be noted that the airflow blockage rate can also be calculated by the point cloud density in the conical space in the normal direction of the air outlet.

[0053] Further, the specific process of determining the opening angle and detection depth of the conical space is: through fluid dynamics experiment, the diffusion form of cold air of the air outlet under the current wind speed and the current damper opening is tested.

[0054] The maximum diffusion angle and the farthest distance of the cold air blown out of the air outlet are obtained, the effective air supply conical space of the air outlet is constructed, and the maximum diffusion angle and the farthest distance are respectively set as the opening angle and the detection depth of the conical space.

[0055] In another specific embodiment, the opening angle and detection depth of the effective air supply conical space of the air outlet are determined by CFD simulation.

[0056] Further, the specific process of screening the point cloud located in the effective air supply conical space is: the opening angle and the detection depth of the effective air supply conical space of the air outlet are respectively denoted as and , .

[0057] Each point cloud after conversion is traversed , wherein represents the number of point clouds, .

[0058] The point cloud that satisfies the following two conditions at the same time is screened out and is denoted as an effective space point cloud.

[0059] (1) Distance condition: .

[0060] (2) Angle condition: .

[0061] It should be noted that the distance condition limits that the point cloud must be located in front of the air outlet and within the detection depth, i.e. the point cloud is within the length range of the conical space; the angle condition limits that the lateral offset of the point cloud cannot exceed the conical radius corresponding to its z-axis depth, i.e. the point cloud is within the opening angle range of the conical space.

[0062] Further, the specific working process of evaluating the air flow restriction degree of the air outlet in the air flow restriction evaluation module is as follows: based on the relative distance and the relative angle between the object and the air outlet, the mapping relationship between the preset relative distance and relative angle and the air flow restriction compensation factor is inquired, the air flow restriction compensation factor corresponding to the relative distance and the relative angle is determined, and is accumulated to obtain the air flow restriction compensation amount of the air outlet.

[0063] According to the air flow blockage rate of the air outlet and the air flow restriction compensation amount, the air flow restriction degree of the air outlet is obtained through weighted fusion analysis , .

[0064] It should be noted that through fluid dynamics simulation and wind tunnel experiment, the actual obstruction of the air outlet under different relative distances and relative angles is analyzed, and the quantitative corresponding relationship between the relative distance and the air flow restriction compensation factor and the relative angle and the air flow restriction compensation factor is established, and is preset in the form of a query table or a fitting function. The closer the relative distance, the smaller the relative angle, and the larger the air flow restriction compensation factor.

[0065] It should be noted that the weights of the air flow blockage rate and the air flow restriction compensation amount can be set according to fluid dynamics experience, or can be obtained through a limited number of air supply test data, such as collecting historical data of air outlet speed and temperature distribution under different obstruction conditions, calculating the correlation coefficients of air flow blockage rate and air flow restriction compensation amount respectively affecting air supply efficiency, using regression analysis or principal component analysis to determine the contribution of the two to the air flow restriction degree, and finally after normalization, the contribution is converted into the corresponding weight and the sum is 1.

[0066] It should be noted that the weight of the air flow blockage rate is greater than the weight of the air flow restriction compensation amount.

[0067] It should be noted that when evaluating the air flow restriction degree of the air outlet, in addition to the air flow blockage rate, the relative distance and the relative angle between the object and the air outlet are further introduced, because different distances and angles will significantly affect the actual obstruction form and energy loss of the air flow. The object close to the air outlet or directly facing the air outlet may cause serious turbulence of the local air flow even if the volume is small. The role of this is to quantify the influence of the above space pose factors through the compensation factor, correct the deviation that may be caused by only relying on the volume blockage rate, and thus more accurately and comprehensively reflect the real air flow restriction condition.

[0068] In this embodiment, the air flow blockage rate is calculated based on three-dimensional point cloud data, the air flow restriction degree of the air outlet is comprehensively evaluated in combination with the space pose compensation factor, and the limitations of only relying on distance or volume judgment are overcome, which is more in line with the actual air flow organization characteristics.

[0069] The opening degree initial setting module judges whether to reduce the damper opening degree according to the airflow restriction degree of the air outlet, if yes, determines the reduction amount of the damper opening degree, and analyzes the increase amount of the damper opening degree of each adjacent air outlet of the air outlet, controls the air volume adjusting device to adjust the damper opening degree, if no, keeps the original damper opening degree.

[0070] Further, the specific working process of the opening degree initial setting module is: S1: judging whether the airflow restriction degree of the air outlet is greater than or equal to a preset first threshold, if yes, the damper opening degree needs to be reduced and S2 is executed, if no, keeping the current damper opening degree of the air outlet unchanged.

[0071] S2: determining the final damper opening degree of the air outlet according to the preset corresponding rule of the airflow restriction degree range and the damper opening degree, and combining the initial damper opening degree, calculating the reduction amount of the damper opening degree of the air outlet.

[0072] S3: identifying each adjacent air outlet of the air outlet according to the air outlet layout topology structure of the ultra-low temperature freezer.

[0073] S4: analyzing the airflow restriction degree of each adjacent air outlet, calculating the increase amount of the damper opening degree of each adjacent air outlet based on the preset adjacent air outlet compensation rule, the compensation rule is defined by the following formula: , wherein represents the increase amount of the damper opening degree of the i-th adjacent air outlet, , represents the reduction amount of the damper opening degree of the air outlet, represents a preset weight coefficient and satisfies , represents the airflow restriction degree of the i-th adjacent air outlet.

[0074] S5: controlling the air volume adjusting device to adjust the damper opening degree of the air outlet and the corresponding adjacent air outlet according to the calculated reduction amount and increase amount.

[0075] It should be noted that when setting the corresponding rule of the airflow restriction degree range and the damper opening degree, based on fluid simulation and air duct characteristic experiment, analyzing the minimum air supply required to maintain the target temperature in the cabinet under different airflow restriction degree intervals, establishing the quantitative matching relationship between the airflow restriction degree range and the damper opening degree, and presetting in the form of query table or piecewise function.

[0076] It should be noted that the method of analyzing the airflow restriction degree of each adjacent air outlet and the method of analyzing the airflow restriction degree of the air outlet have the same principle.

[0077] ​​It should be noted that the weight coefficient in the compensation rule for the adjacent air outlet is an empirical value less than 1, which is used to allocate the compensation air volume to avoid overcompensation. In a specific embodiment, the weight coefficient is 0.7.

[0078] It should be noted that the more unobstructed the adjacent air outlet is, the more compensation air volume is obtained.

[0079] It should be noted that the air volume allocation strategy of the ultra-low temperature freezer is to suppress the air volume of the airflow-restricted air outlet and enhance the air volume of the adjacent unobstructed air outlet. In the present application, the air velocity of each air outlet of the ultra-low temperature freezer is uniformly adjusted to ensure the basic airflow circulation and efficiency of the entire refrigeration system, but the damper opening degree of each air outlet is independently adjustable to achieve precise temperature zoning control and air volume allocation. Therefore, the specific adjustment measures for the air volume of each air outlet in the present application are as follows: for the air outlet with high airflow restriction degree, the damper opening degree is instructed to decrease to reduce the air volume, thereby preventing the direct blowing of cold air to the goods from causing waste and local overcooling; at the same time, the damper opening degree of the adjacent air outlet with lower airflow restriction degree is instructed to increase to increase the air volume, thereby guiding the cold air flow to bypass the obstacle and compensate for the refrigeration of the blocked area.

[0080] It should be noted that a wind volume adjusting device is provided corresponding to each air outlet in the ultra-low temperature freezer, and the wind volume adjusting device is a vane type damper driven by a stepper motor or a servo motor, which is used to independently adjust the opening degree of the air outlet and thereby realize air volume adjustment. The damper is installed in each air outlet or in the independent branch air duct connected to each air outlet.

[0081] Further, the corresponding rule between the airflow restriction degree range and the damper opening degree is as follows: , wherein represents the final damper opening degree, represents the initial damper opening degree, represents the set minimum damper opening degree, , respectively represent the first threshold value and the second threshold value of the preset airflow restriction degree, .

[0082] It should be noted that the setting of the first threshold value and the second threshold value of the airflow restriction degree is based on fluid dynamics simulation and wind tunnel test data, and is determined by analyzing the inflection points of the supply efficiency under different blockage conditions: the critical point at which the supply efficiency begins to decrease significantly is set as the first threshold value, and the critical point at which the supply efficiency decreases to the lower limit of the acceptable range and needs to be forced to intervene to maintain the basic operation of the system is set as the second threshold value.

[0083] It should be noted that the setting of the minimum damper opening degree is based on the principle of ensuring the safe and stable operation of the ultra-low temperature freezer refrigeration system. The minimum opening degree that can be maintained by the damper of this model under the premise of controllable frosting risk and non-overload or surge of the fan motor is determined through experiments, and the minimum circulating air volume requirement of the system is considered to determine the minimum damper opening degree.

[0084] In one embodiment, the first threshold and the second threshold of the airflow restriction degree are 0.2 and 0.6 respectively, and the set minimum damper opening degree is 10%.

[0085] It should be noted that when the obstruction is slight, the air is supplied at normal air volume; the more serious the obstruction, the more the air volume of the outlet is reduced; when the obstruction is high, the damper opening degree is reduced to the set minimum value, only a small amount of ventilation is maintained, and the outlet is prevented from being completely blocked by frost.

[0086] In this embodiment, the damper opening degree of the outlet is dynamically adjusted according to the airflow restriction degree, and the damper opening degree of the adjacent outlet is also adjusted, so that the air volume is intelligently distributed, avoiding local overcooling or overheating, and improving the overall refrigeration efficiency.

[0087] The opening degree redistribution module continuously monitors the return temperature of each adjacent outlet through a temperature sensor, and redistributes the damper opening degree of each adjacent outlet based on the difference between the return temperature of each adjacent outlet and the set temperature and the difference between the return temperatures of adjacent outlets.

[0088] Further, the specific working process of the opening degree redistribution module is as follows: T1: continuously monitor the return temperature of each adjacent outlet through a high-precision temperature sensor arranged in the return area of each adjacent outlet.

[0089] T2: determine whether the return temperature of each adjacent outlet meets the following conditions at the same time: (1) the difference between the return temperature of each adjacent outlet and the set return temperature is within the preset allowable range.

[0090] (2) the difference between the return temperatures of any two adjacent outlets is less than the set threshold; if both conditions are met, the current damper opening degree of each adjacent outlet is kept unchanged, otherwise, T3 is executed.

[0091] T3: identify the adjacent outlets with high and low return temperatures, and increase the damper opening degree of the adjacent outlet with high temperature and decrease the damper opening degree of the adjacent outlet with low temperature in a gradient adjustment manner according to the preset damper opening degree unit adjustment amount, until the return temperature meets the conditions of T2.

[0092] It should be noted that the poses of different article placement spaces and the corresponding optimal damper opening configurations are recorded, and when a similar space pose is identified again, the historical optimal configuration is preferentially called as a basis of the initial damper opening control signal, so as to accelerate the adjustment speed and further optimize the energy efficiency.

[0093] Further, the specific process of identifying the adjacent air outlet with the high and low return temperature is that the return temperature of each adjacent air outlet is compared with the set return temperature.

[0094] If the difference between the return temperature of an air outlet and the set temperature exceeds the allowable range, and the return temperature of the air outlet is higher than the set value, the air outlet is recorded as a first type of adjacent air outlet with high temperature, and if the return temperature of the air outlet is lower than the set value, the air outlet is recorded as a first type of adjacent air outlet with low temperature.

[0095] The average value of the return temperatures of all adjacent air outlets is calculated, and the fluctuation range of the return temperature is determined according to a preset threshold of the difference between the return temperatures of adjacent air outlets.

[0096] If the return temperature of an air outlet is higher than the upper limit of the fluctuation range, the air outlet is recorded as a second type of adjacent air outlet with high temperature.

[0097] If the return temperature of an air outlet is lower than the lower limit of the fluctuation range, the air outlet is recorded as a second type of adjacent air outlet with low temperature.

[0098] The first type and the second type of adjacent air outlets with high and low temperature are summarized to obtain a set of adjacent air outlets with high and low return temperature.

[0099] In the embodiment, the application continuously monitors the return temperature of the adjacent air outlet, redistributes the damper opening of the adjacent air outlet, ensures the uniform and stable temperature in the cabinet, and further improves the energy efficiency and control accuracy.

[0100] In the embodiment, the application reduces the air volume of the blocked air outlet, increases the air volume of the unblocked air outlet, effectively reduces the energy consumption of the fan, prevents local frosting and system overload, and prolongs the service life of the equipment.

[0101] The above embodiments can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When realized by software, the above embodiments can be realized in the form of a computer program product in whole or in part.

[0102] Those skilled in the art can understand that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0103] In addition, each functional module in each embodiment of the present application can be integrated in one processing module, or each module can exist physically alone, or two or more modules can be integrated in one module.

[0104] The above is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0105] Finally, the above is only the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be covered in the protection scope of the present application.

Claims

1. An ultra-low temperature freezer based on energy saving control, characterized by, The application comprises: an article stacking perception module, which scans the articles stacked in the area in front of the air outlet in real time through a 3D vision sensor, establishes a three-dimensional point cloud model of the articles, and obtains the relative distance and relative angle between the articles and the air outlet; a airflow restriction evaluation module, which analyzes the volume occupancy rate in the conical space in the normal direction of the air outlet based on the three-dimensional point cloud model, calculates the airflow obstruction rate, and evaluates the airflow restriction degree of the air outlet in combination with the relative distance and relative angle; an opening degree initial setting module, which determines whether to reduce the damper opening degree according to the airflow restriction degree of the air outlet, determines the reduction amount of the damper opening degree if yes, analyzes the increase amount of the damper opening degree of each adjacent air outlet of the air outlet, controls the air volume adjusting device to adjust the damper opening degree, and keeps the original damper opening degree if no; an opening degree redistribution module, which continuously monitors the backflow temperature of each adjacent air outlet through a temperature sensor, and redistributes the damper opening degree of each adjacent air outlet based on the difference between the backflow temperature of the adjacent air outlet and the set temperature and the difference between the backflow temperatures of the adjacent air outlets; the specific working process of calculating the airflow obstruction rate in the airflow restriction evaluation module is as follows: D1: the center point of the air outlet is taken as the vertex, and the normal direction of the air outlet is taken as the central axis to construct the effective air supply conical space of the air outlet, and the opening angle and the detection depth of the conical space are determined; D2: the three-dimensional coordinate system established with the center point of the 3D vision sensor as the origin is recorded as the sensor coordinate system; the original point cloud data is obtained based on the three-dimensional point cloud model of the articles, and preliminary noise reduction processing is performed to obtain the preprocessed point cloud and its three-dimensional coordinates in the sensor coordinate system; D3: the three-dimensional coordinate system established with the center point of the air outlet as the origin and the normal direction of the air outlet as the Z axis is recorded as the air outlet coordinate system; D4: the offset parameters of the center point of the 3D vision sensor relative to the center point of the air outlet are measured, and the offset parameters include the position offset and the angle offset; a fixed transformation matrix from the sensor coordinate system to the air outlet coordinate system is constructed based on the offset parameters; D5: the three-dimensional coordinates of the preprocessed point cloud in the sensor coordinate system are converted to the air outlet coordinate system by applying the transformation matrix to obtain the converted point cloud data; D6: the three-dimensional coordinates of the converted point cloud are used to screen the point cloud located in the effective air supply conical space, which is recorded as the effective space point cloud; D7: the effective air supply conical space is divided into a plurality of cubic units according to the preset equal volume principle, and each unit is recorded as a voxel; The specific working process of evaluating the air flow restriction degree of the air outlet in the air flow restriction evaluation module is as follows: based on the relative distance and the relative angle between the article and the air outlet, a mapping relationship between the preset relative distance and relative angle and an air flow restriction compensation factor is inquired, the air flow restriction compensation factor corresponding to the relative distance and the relative angle is determined, and accumulation is performed to obtain an air flow restriction compensation amount of the air outlet; and according to the air flow blockage rate of the air outlet and the air flow restriction compensation amount, a weighted fusion analysis is performed to obtain the air flow restriction degree of the air outlet , ; D8: it is judged whether each voxel contains effective space point cloud: if yes, the voxel is recorded as an occupied voxel, otherwise it is recorded as an unoccupied voxel; the number of all occupied voxels is counted, and the volume of a single voxel is multiplied to obtain the volume occupied by the articles in the effective air supply space; , wherein represents the final damper opening, represents the initial damper opening, represents the set minimum damper opening, , respectively represent a first threshold value and a second threshold value of a preset airflow restriction degree, .

2. The ultra-low temperature freezer based on energy-saving control according to claim 1, characterized in that: the corresponding rules between the airflow restriction degree range and the damper opening degree are as follows: the specific working process of the article stacking perception module is as follows: The 3D vision sensor deployed near the air outlet scans the objects stacked in the area in front of the air outlet in real time, and a three-dimensional point cloud model of the objects is established based on the sensor data; A normal line of the plane where the air outlet center point is located is taken as a reference line, and the length of the line connecting the article center point and the air outlet center point is obtained , and the included angle between the line and the reference line is obtained , and the included angle is recorded as the relative angle between the article and the air outlet According to and calculating the relative distance between the item and the air outlet .

3. The ultra-low temperature freezer based on energy-saving control according to claim 1, characterized in that: The specific process of determining the opening angle and the detection depth of the conical space is as follows: Through fluid dynamics experiments, the diffusion form of cold air from the air outlet under the current air speed and the current air door opening is tested; The maximum diffusion angle and the farthest distance of the cold air blowing out of the air outlet are obtained, an effective air supply conical space of the air outlet is constructed, and the maximum diffusion angle and the farthest distance are set as the opening angle and the detection depth of the conical space respectively.

4. The ultra-low temperature freezer based on energy-saving control according to claim 1, characterized in that: The specific process of screening the point cloud in the effective air supply conical space is as follows: The opening angle of the effective air supply cone space of the air outlet and the detection depth are respectively denoted as and , ; traversing each point cloud of the transformed point clouds wherein denotes a number of point clouds, ; Screen the point cloud that meets the following two conditions at the same time, and mark it as an effective space point cloud; (1) Distance condition: ; (2) Angle condition: .

5. The ultra-low temperature freezer based on energy-saving control according to claim 1, characterized in that: The specific working process of the initial opening setting module is as follows: S1: Determine whether the airflow restriction degree of the air outlet is greater than or equal to a preset first threshold value, if yes, the air door opening needs to be reduced and S2 is executed, if not, the current air door opening of the air outlet is kept unchanged; S2: According to the corresponding rules of the preset airflow restriction degree range and the air door opening, the final air door opening of the air outlet is determined, and the reduction amount of the air door opening of the air outlet is calculated in combination with the initial air door opening thereof; S3: According to the air outlet layout topology structure of the ultra-low temperature freezer, each adjacent air outlet of the air outlet is identified; S4: Analyze the airflow restriction degree of each adjacent air outlet, and calculate the increasing amount of the air door opening of each adjacent air outlet based on a preset adjacent air outlet compensation rule, the compensation rule is defined by the following formula: wherein represents the increase amount of the th adjacent outlet damper opening, , represents the decrease amount of the outlet damper opening, represents a preset weight coefficient and satisfies , represents the degree of airflow restriction of the th adjacent outlet S5: Control the air volume adjusting device to adjust the air door opening of the air outlet and the corresponding adjacent air outlets according to the calculated reduction amount and increasing amount.

6. The ultra-low temperature freezer based on energy-saving control according to claim 1, characterized in that: The specific working process of the opening redistribution module is as follows: T1: Continuously monitor the backflow temperature of each adjacent air outlet through the high-precision temperature sensor arranged in the backflow area of each adjacent air outlet; T2: Determine whether the backflow temperature of each adjacent air outlet meets the following conditions at the same time: (1) The difference between the backflow temperature of all adjacent air outlets and the set backflow temperature is within a preset allowable range; (2) The difference between the backflow temperatures of any two adjacent air outlets is less than a set threshold value; if both conditions are met, the current air door opening of each adjacent air outlet is kept unchanged, otherwise, T3 is executed; T3: Identify the adjacent air outlets with high and low backflow temperatures, and increase the air door opening of the adjacent air outlet with high temperature and reduce the air door opening of the adjacent air outlet with low temperature in a gradient adjustment manner according to a preset air door opening unit adjustment amount, until the backflow temperature meets the conditions of T2.

7. The ultra-low temperature freezer based on energy-saving control according to claim 6, characterized in that: The specific process of identifying the adjacent air outlets with high and low backflow temperatures is as follows: Compare the backflow temperature of each adjacent air outlet with the set backflow temperature respectively; If the difference between the backflow temperature of a certain air outlet and the set temperature exceeds the allowable range, and the backflow temperature of the certain air outlet is higher than the set value, the certain air outlet is recorded as a type of adjacent air outlet with high temperature, if the backflow temperature of the certain air outlet is lower than the set value, the certain air outlet is recorded as a type of adjacent air outlet with low temperature; Calculate the average of all the adjacent outlet backflow temperatures, and determine the fluctuation range of the backflow temperature according to a preset threshold of the backflow temperature difference between adjacent outlets; If the backflow temperature of an outlet is higher than the upper limit of the fluctuation range, it is recorded as a second type of adjacent outlet with high temperature bias; If the backflow temperature of an outlet is lower than the lower limit of the fluctuation range, it is recorded as a second type of adjacent outlet with low temperature bias; Collect the first and second types of adjacent outlets with high and low temperature bias to obtain a set of adjacent outlets with high and low backflow temperature bias.

Images