Temperature field dynamic adjusting method and device for selective laser sintering

Abstract

The invention relates to the technical field of selective laser sintering, and discloses a temperature field dynamic adjustment method and device for selective laser sintering, and the method comprises the steps: controlling a PLC to output a control signal with a preset duty ratio to a heating loop; under the condition that control signals with different preset duty ratios are obtained, the current value, sent by the current acquisition module, of the heating loop is used for carrying out abnormity judgment on the heating pipe based on the current value of the heating loop; if the heating pipe is in the abnormal state, calculating the power loss rate of the heating pipe based on the current value of the heating loop; and determining a temperature field adjustment duty ratio based on the power loss rate of the heating tube, and dynamically adjusting the temperature field based on the temperature field adjustment duty ratio. Accurate early warning of the abnormal state of the heating equipment is achieved, normal production of the heating equipment is guaranteed, the production efficiency of the heating equipment is improved, and economic losses of customers are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of selective laser sintering, and in particular to a temperature field dynamic adjustment method and device for selective laser sintering. Background Art

[0002] The basic process of selective laser sintering heating is: before selective laser sintering, the pre-sintered powder is first preheated by a heating temperature field to make the powder surface evenly reach the optimal sintering temperature and eliminate the powder surface stress to a certain extent; secondly, after the powder is preheated, a heating temperature field is required to keep the forming cavity powder and the forming cavity powder warm after sintering to reduce the temperature difference between the sintering surface and the powder, eliminate the powder surface stress to a certain extent, and make the powder surface better sintered and formed. Temperature control plays a vital role in ensuring printing quality, improving printing efficiency and expanding application areas.

[0003] During the selective laser sintering heating process, the heating and insulation purposes are achieved through the heating device. However, when an abnormality occurs in the heating device, the abnormal heating tube cannot be accurately identified, which affects the heating and causes the temperature field to be out of control, thereby affecting the production quality and efficiency of the equipment and causing economic losses. Summary of the invention

[0004] In view of this, the present invention provides a method and device for dynamically adjusting the temperature field for selective laser sintering to solve the problem that when an abnormal heating device occurs, the abnormal heating tube cannot be accurately identified, which affects the heating and causes the temperature field to be uncontrollable.

[0005] In a first aspect, the present invention provides a method for dynamic temperature field regulation for selective laser sintering, which is applied to a host computer in a heating device, wherein the heating device includes a host computer, a PLC, a current acquisition module and a multi-channel heating circuit, the heating circuit is respectively connected to the PLC and the current acquisition module, and the host computer is connected to the PLC; the heating circuit includes a solid-state relay and a heating tube, and the solid-state relay is connected to the heating tube; the method includes:

[0006] Control the PLC to output a control signal with a preset duty cycle to the heating circuit;

[0007] Under the control signals with different preset duty cycles, the current value of the heating circuit sent by the current acquisition module is used to judge the abnormality of the heating tube based on the current value of the heating circuit;

[0008] If the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit;

[0009] The temperature field adjustment duty cycle is determined based on the power loss rate of the heating tube, and the temperature field is dynamically adjusted based on the temperature field adjustment duty cycle.

[0010] The present embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering. The upper computer controls the PLC to output control signals of preset duty cycles to the heating circuits. The output power of the heating tube can be controlled by the solid-state relay, and the current value of the heating circuit can be obtained by the current acquisition module. The heating tube is judged to be abnormal based on the current value of the heating circuit, which greatly shortens the time for troubleshooting and reduces the difficulty of abnormal handling, realizes accurate early warning of the heating equipment, and determines the temperature field adjustment duty cycle based on the power loss rate of the heating tube. The temperature field is dynamically adjusted based on the temperature field adjustment duty cycle, which ensures the normal production of the heating equipment, thereby improving the production efficiency of the heating equipment and reducing the economic losses of customers.

[0011] In an optional implementation, the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles is obtained, and the abnormality judgment of the heating tube is performed based on the current value of the heating circuit, including:

[0012] When the preset duty cycle is less than the determined duty cycle, the first heating current value of the heating circuit sent by the current acquisition module is obtained, and the first heating current value is compared with the duty cycle current value. If the first heating current value is greater than the duty cycle current value, the heating tube is in a solid-state breakdown state;

[0013] When the preset duty cycle is greater than the determined duty cycle, the second heating current value of the heating circuit sent by the current acquisition module is obtained, and the second heating current value is compared with the duty cycle current value. If the second heating current value is less than the duty cycle current value, the heating tube is in a short circuit state or an open circuit state.

[0014] The present embodiment provides a method for dynamic temperature field regulation for selective laser sintering, which achieves accurate determination of abnormal conditions of the heating tube and precise early warning of the heating equipment by comparing the preset duty cycle with the determined duty cycle, and the current value of the heating circuit with the duty cycle current value.

[0015] In an optional implementation, obtaining the control signal with different preset duty cycles, the current value of the heating circuit sent by the current acquisition module is used to judge the abnormality of the heating tube based on the current value of the heating circuit, and further comprising:

[0016] The actual current value of the heating circuit under the control signal of different preset duty cycles is obtained through the current acquisition module, and the current deviation is determined based on the actual current value and the theoretical current value;

[0017] The current deviation is compared with a preset error range. If the current deviation does not match the preset error range, the heating tube is in an aging state.

[0018] The present embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering, which compares the current deviation between the actual current value and the theoretical current value of the heating circuit under control signals of different preset duty cycles with a preset error range, thereby achieving accurate judgment and early warning of the aging state of the heating tube in the heating circuit.

[0019] In an optional implementation, if the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit, including:

[0020] The heating tube power and the heating tube voltage are obtained, and the heating tube power loss rate is calculated based on the current deviation, the heating tube power and the heating tube voltage.

[0021] In an optional implementation, before controlling the PLC to output control signals with preset duty cycles to the heating circuits respectively, the method further includes:

[0022] When the heating device is in standby mode, the initial current value of the heating circuit sent by the current acquisition module is obtained, and the initial current value is compared with the duty cycle current value. If the initial current value is greater than / equal to the duty cycle current value, the heating tube is in a solid-state breakdown state.

[0023] The present embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering. By comparing the initial current value with the duty cycle current value when the heating device is in standby mode, the abnormal state of the heating tube is determined before the heating device heats up. The heating tube is then replaced to ensure normal production of the heating device, thereby reducing economic losses.

[0024] In an optional implementation, determining the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjusting the temperature field based on the temperature field adjustment duty cycle includes:

[0025] Obtain the default duty cycle of the temperature field, and determine the average duty cycle based on the default duty cycle of the temperature field and the power loss rate of the heating tube;

[0026] The duty cycle average value is used as the temperature field adjustment duty cycle, and the temperature field is dynamically adjusted using the temperature field adjustment duty cycle.

[0027] This embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering. The average duty cycle is determined by the default duty cycle of the temperature field and the power loss rate of the heating tube, and the average duty cycle is used as the temperature field adjustment duty cycle. The temperature field is dynamically adjusted using the temperature field adjustment duty cycle, thereby achieving a dynamic balance of the temperature field power demand and ensuring the stability of the powder sintering temperature field.

[0028] In a second aspect, the present invention provides a temperature field dynamic adjustment device for selective laser sintering, which is applied to a host computer in a heating device, and the device comprises:

[0029] A control module, used to control the PLC to output control signals with preset duty ratios to the heating circuits;

[0030] An abnormality judgment module is used to obtain the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and to judge the abnormality of the heating tube based on the current value of the heating circuit;

[0031] A calculation module, used for calculating the power loss rate of the heating tube based on the current value of the heating circuit if the heating tube is in an abnormal state;

[0032] The dynamic adjustment module is used to determine the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjust the temperature field based on the temperature field adjustment duty cycle.

[0033] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the temperature field dynamic adjustment method for selective laser sintering of the above-mentioned first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for dynamic temperature field adjustment for selective laser sintering of the first aspect or any corresponding embodiment thereof.

[0035] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method for dynamically adjusting the temperature field for selective laser sintering according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is a schematic structural diagram of a heating device according to an embodiment of the present invention;

[0038] Figure 2 is a circuit diagram for realizing intelligent identification of heating tube loss and dynamic adjustment of temperature field in selective laser sintering according to an embodiment of the present invention;

[0039] Figure 3 is a schematic flow chart of a method for dynamically adjusting a temperature field for selective laser sintering according to an embodiment of the present invention;

[0040] Figure 4 is a schematic diagram of a curve of relationship between input percentage and output power of a solid-state relay according to an embodiment of the present invention;

[0041] Figure 5 is a schematic flow chart of another method for dynamically adjusting the temperature field for selective laser sintering according to an embodiment of the present invention;

[0042] Figure 6 is a schematic flow chart of another method for dynamically adjusting the temperature field for selective laser sintering according to an embodiment of the present invention;

[0043] Figure 7 is a structural block diagram of a temperature field dynamic adjustment device for selective laser sintering according to an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0046] During the selective laser sintering heating process, the heating device is composed of several heating tubes, solid-state relays, PLC (Programmable Logic Controller) and temperature sensors. Several heating tubes are fixedly arranged at the top of the lower working chamber in an array layout. Although the heating device can achieve the purpose of heating and heat preservation, since the heating tubes are fixedly arranged at the top of the lower working chamber in an array layout, when the heating tubes are aged, short-circuited, open-circuited, or solid-state breakdown occurs, it is impossible to accurately determine the faulty heating tube, and it is also impossible to determine the solid-state breakdown. It takes a long time and is difficult to troubleshoot the problem. When there is an abnormality in the heating device, it will directly affect the heating, resulting in the inability to control the temperature field, which in turn affects the production quality and efficiency of the equipment and causes economic losses to customers.

[0047] In order to solve the above technical problems, the embodiment of the present invention provides a method for dynamically adjusting the temperature field for selective laser sintering, which is applied to the host computer 101 in the heating device, such as Figure 1As shown, the heating device includes a host computer 101, a PLC 102, a current acquisition module 103 and a multi-channel heating circuit. Figure 2 As shown, the heating circuit is connected to PLC102 and current acquisition module 103 respectively, and host computer 101 is connected to PLC102; the heating circuit includes solid-state relay 104 and heating tube 105, and solid-state relay 104 and heating tube 105 are connected.

[0048] Among them, the heating tube 105 is a heating element, serving as a heat source; the solid-state relay 104 performs analog quantity adjustment to control the power output of the heating tube 105, thereby regulating the temperature of the temperature field; PLC102 serves as a controller to control the output duty cycle through PID (Proportional Integral Derivative) to control the solid-state relay 104, thereby controlling the heating tube 105.

[0049] The heating device also includes an infrared sensor 106, which collects the temperature of the heating temperature field as temperature feedback for PLC-PID regulation, so that the entire heating temperature field forms a closed-loop control.

[0050] The current acquisition module 103 includes an acquisition transmitter 107 and a current transformer 108, which are used to collect the current data of the heating tube. The current acquisition module 103 collects the current value of each current transformer; the current acquisition module 103 interacts with PLC102 and the host computer 101 through the MDBUS RTU protocol (a communication protocol widely used in the field of industrial control, mainly used for data exchange between devices), and PLC102 and the host computer 101 interact with each other to realize data processing judgment and dynamic adjustment of the algorithm, judge the aging, short circuit, open circuit, and solid breakdown of the heating tube 105, accurately output equipment warnings, intelligently identify the loss of the heating tube and dynamically adjust the temperature field to ensure the stability of the powder sintering temperature field.

[0051] According to an embodiment of the present invention, an embodiment of a method for dynamically adjusting the temperature field for selective laser sintering is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0052] In this embodiment, a method for dynamically adjusting the temperature field for selective laser sintering is provided, which can be used in the above-mentioned host computer 101. Figure 3 is a flow chart of a method for dynamically adjusting the temperature field for selective laser sintering according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0053] Step S301: Control the PLC to output control signals with preset duty cycles to the heating circuit respectively.

[0054] Specifically, as Figure 2 shown, when the equipment pre-construction enters the heating self-check mode, according to the number of heating circuits set by the host computer and the number of circuits for each round of heating, the self-check target number of times is automatically calculated. After the PLC receives the self-check enable command sent by the host computer, it outputs a control signal for 160 s at duty cycles of 40%, W%, E%, and R%, where 40 < W < E < R <= 100, and a control signal for 40 s is output for each stage corresponding to the duty cycle. W can be set to 60, E can be set to 80, and R can be set to 100.

[0055] Step S302: Obtain the current values of the heating circuit sent by the current acquisition module under control signals with different preset duty cycles, and perform an abnormality determination on the heating tube based on the current values of the heating circuit.

[0056] Specifically, as Figure 1 shown, the PLC, as a controller, controls the solid-state relay by PID regulation to output the duty cycle. As Figure 4 shown, the solid-state relay controls the power output of the heating tube according to the input percentage and output power relationship curve, and the real-time current values of each power stage of the heating tube (i.e., the current values of the heating circuit) are collected through the current acquisition module.

[0057] Step S303: If the heating tube is in an abnormal state, calculate the power loss rate of the heating tube based on the current value of the heating circuit.

[0058] Specifically, the abnormal states of the heating tube include solid-state breakdown state, short-circuit state, open-circuit state, and aging state.

[0059] Step S304: Determine the temperature field regulation duty cycle based on the power loss rate of the heating tube, and perform dynamic regulation on the temperature field based on the temperature field regulation duty cycle.

[0060] A temperature field dynamic regulation method for selective laser sintering provided in this embodiment. The host computer controls the PLC to output control signals with preset duty cycles to the heating circuit respectively, can control the output power of the heating tube through the solid-state relay, and then obtain the current value of the heating circuit through the current acquisition module. An abnormality determination is performed on the heating tube through the current value of the heating circuit, which greatly shortens the problem troubleshooting time and reduces the difficulty of abnormality handling, realizing precise early warning of the heating equipment. Moreover, the temperature field regulation duty cycle is determined based on the power loss rate of the heating tube, and the temperature field is dynamically regulated based on the temperature field regulation duty cycle, ensuring the normal production of the heating equipment, thereby improving the production efficiency of the heating equipment and reducing the economic losses of customers.

[0061] In this embodiment, a method for dynamically adjusting the temperature field for selective laser sintering is provided, which can be used in the above-mentioned host computer 101. Figure 5 is a flow chart of a method for dynamically adjusting the temperature field for selective laser sintering according to an embodiment of the present invention. Figure 5 As shown, the process includes the following steps:

[0062] Step S501, control the PLC to output control signals with preset duty ratios to the heating circuits. Figure 3 Step S301 of the illustrated embodiment will not be described in detail here.

[0063] Step S502, obtaining the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and making an abnormal judgment on the heating tube based on the current value of the heating circuit.

[0064] Specifically, the above step S502 includes:

[0065] Step S5021, when the preset duty cycle is less than the determined duty cycle, obtain the first heating current value of the heating circuit sent by the current acquisition module, and compare the first heating current value with the duty cycle current value. If the first heating current value is greater than the duty cycle current value, the heating tube is in a solid-state breakdown state.

[0066] Specifically, assuming that the duty cycle is determined to be 20%, when the preset duty cycle output by the PLC is less than 20%, and the first heating current value of the heating circuit is greater than the current value of the 20% duty cycle, the heating tube is in a solid-state breakdown state, which causes abnormal heating of the heating tube.

[0067] Furthermore, when the heating device is in standby mode, the initial current value of the heating circuit sent by the current acquisition module is obtained, and the initial current value is compared with the duty cycle current value. If the initial current value is greater than / equal to the duty cycle current value, the heating tube is in a solid-state breakdown state.

[0068] Furthermore, when the heating device is in standby mode and the heating device is not enabled for heating, no control signal of a preset duty cycle is output, and when the initial current value collected by the current acquisition module is greater than or equal to a 20% duty cycle current value, it is determined that there is solid-state breakdown causing the heating tube to automatically heat abnormally;

[0069] Step S5022, when the preset duty cycle is greater than the determined duty cycle, obtain the second heating current value of the heating circuit sent by the current acquisition module, and compare the second heating current value with the duty cycle current value. If the second heating current value is less than the duty cycle current value, the heating tube is in a short circuit state or an open circuit state.

[0070] Specifically, when the heating is turned on, when the PLC output duty cycle is greater than 20% and the second heating current value collected by the current acquisition module is less than 0.5A, the heating tube is in a short circuit state or an open circuit state, and an alarm is triggered by the host computer after a delay.

[0071] Step S5023, obtaining the actual current value of the heating circuit under the control signal of different preset duty cycles through the current acquisition module, and determining the current deviation based on the actual current value and the theoretical current value.

[0072] Specifically, the heating tube aging logic judgment is entered within the last 5S of each control stage, that is, after completing the current round, the PLC uploads the duty cycle to determine whether the deviation between the actual current value and the theoretical current value of the heating circuit at each output duty cycle within the last 5S exceeds the allowable error of ±0.5A. If the current deviation of the same heating tube exceeds the allowable error when outputting two or more ratios of rated power, then it is considered that the heating circuit is aged, and the host computer alarms the aging of the heating circuit.

[0073] Step S5024, comparing the current deviation with a preset error range. If the current deviation does not match the preset error range, the heating tube is in an aging state.

[0074] Step S503, if the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit.

[0075] Specifically, the heating tube power and the heating tube voltage are obtained, and the heating tube power loss rate is calculated based on the current deviation, the heating tube power and the heating tube voltage.

[0076] Furthermore, the heating equipment is pre-built into the heating self-test mode, and the host computer performs heating self-test. When the heating tube is judged to be aged by the current value of the heating circuit (excluding short circuit, open circuit and solid-state breakdown), the power loss rate of the heating tube is automatically calculated. The calculation formula of the power loss rate η of the heating tube is as follows:

[0077] η=U*△I / P*100% (1)

[0078] △I=I-I1 (2)

[0079] Among them, U represents the voltage of the heating tube, △I represents the current deviation, P represents the power of the heating tube, I1 represents the actual current value, and I represents the theoretical current value.

[0080] Furthermore, if the power loss rate of the heating tube is greater than the set value X=45%, the host computer prompts to replace the heating tube, X=(45~60); if the power loss rate of the heating tube is less than the set value X%, the temperature field is dynamically adjusted.

[0081] Step S504: determine the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjust the temperature field based on the temperature field adjustment duty cycle. Figure 3 Step S304 of the illustrated embodiment will not be described in detail here.

[0082] The present embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering. By comparing the preset duty cycle with the determined duty cycle, and the current value of the heating circuit with the duty cycle current value, the abnormal state of the heating tube and the precise early warning of the heating equipment are accurately determined. Secondly, by comparing the current deviation between the actual current value and the theoretical current value of the heating circuit under the control signal of different preset duty cycles with the preset error range, the aging state of the heating tube in the heating circuit is accurately determined and early warning is achieved. Finally, by comparing the initial current value with the duty cycle current value when the heating equipment is in standby state, the abnormal state of the heating tube is determined before the heating equipment is heated, and then the normal production of the heating equipment is ensured by replacing the heating tube, thereby reducing economic losses.

[0083] In this embodiment, a method for dynamically adjusting the temperature field for selective laser sintering is provided, which can be used in the above-mentioned host computer 101. Figure 6 is a flow chart of a method for dynamically adjusting the temperature field for selective laser sintering according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps:

[0084] Step S601, control the PLC to output control signals with preset duty ratios to the heating circuits. Figure 5 Step S501 of the illustrated embodiment will not be described in detail here.

[0085] Step S602, obtaining the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and judging the abnormality of the heating tube based on the current value of the heating circuit. Figure 1 Step S502 of the illustrated embodiment will not be described in detail here.

[0086] Step S603: If the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit. Figure 5 Step S503 of the illustrated embodiment will not be described in detail here.

[0087] Step S604, determining the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjusting the temperature field based on the temperature field adjustment duty cycle.

[0088] Specifically, the above step S604 includes:

[0089] Step S6041, obtaining the default duty cycle of the temperature field, and determining the average duty cycle based on the default duty cycle of the temperature field and the power loss rate of the heating tube.

[0090] Specifically, the calculation formula of the power P1 after the heating tube is lost is as follows:

[0091] P1=P*(1-η) (3)

[0092] Furthermore, assuming that the default duty cycle of the temperature field is Z, and the duty cycle of the heating tube power loss output is Z1, the expression for the dynamic balance temperature field power demand is as follows:

[0093] P*Z=P1*Z1 (4)

[0094] Furthermore, the calculation formula for the duty cycle of the power loss output of the heating tube after dynamically adjusting the temperature field is as follows:

[0095] Z1=Z / (1-U*(I-I1) / P*100%) (5)

[0096] Furthermore, the duty cycle after the heating tube power loss dynamically adjusts the temperature field, that is, the calculation formula of the duty cycle average value is as follows:

[0097] ΣZ=(Z1+Z2+...+Zn) / n) (6)

[0098] Where n is the number of duty cycle output stages.

[0099] Step S6042: Using the duty cycle average value as the temperature field adjustment duty cycle, and dynamically adjusting the temperature field using the temperature field adjustment duty cycle.

[0100] Specifically, after determining the loss of the heating tube, the average value of the duty cycle of the heating device after entering a stable state is used as the final duty cycle of the dynamically adjusted temperature field.

[0101] This embodiment provides a method for dynamically adjusting the temperature field for selective laser sintering. The average duty cycle is determined by the default duty cycle of the temperature field and the power loss rate of the heating tube, and the average duty cycle is used as the temperature field adjustment duty cycle. The temperature field is dynamically adjusted using the temperature field adjustment duty cycle, thereby achieving a dynamic balance of the temperature field power demand and ensuring the stability of the powder sintering temperature field.

[0102] The specific steps of a method for dynamically adjusting the temperature field for selective laser sintering are described below through a specific embodiment.

[0103] Embodiment 1:

[0104] The specific steps to achieve intelligent identification of heater loss and dynamic adjustment of temperature field in selective laser sintering include:

[0105] As shown in Table 1 below, the theoretical current values ​​of the heating tube at various powers are used as reference values ​​for the heating self-test function to judge the aging of the heating tube and the self-tuning function of the heating tube temperature field control.

[0106] Table 1:

[0107]

[0108] As shown in Table 2 below, for the judgment of short circuit, open circuit and solid-state breakdown of the heating tube, for the first heating circuit, under different duty cycle control conditions, the detection current is about 5.5A, and the current collected by the current acquisition module is greater than or equal to the 20% duty cycle current value, indicating that the heating circuit has solid-state breakdown; for the first heating circuit, under different duty cycle control conditions, the detection current is 0A, the PLC output duty cycle is greater than 20%, and the external current detection module channel current is less than 0.05A, indicating that the heating tube is burned out.

[0109] Table 2:

[0110]

[0111] As shown in Table 3 below, the heater ages and dynamically adjusts the temperature field.

[0112] Table 3:

[0113]

[0114] The actual current values ​​of the first heating tube at 40%, 60%, 80%, and 100% duty cycle output are compared with the theoretical current values, and the results are shown in Table 4 below:

[0115] Table 4:

[0116]

[0117] The current deviations of the first channel in the above four sets of data are all greater than 0.5A, which indicates that the lamp tube is aging. At this time, the host computer warns that the heating tube is aging.

[0118] The heating tube loss rate in the four stages is less than the set value X (45%). The upper computer determines to directly enter the dynamic adjustment of the temperature field self-adjustment. The default duty cycle of the temperature field is Z=45%, Z1=59.3%, Z2=55.9%, Z3=63.8%, Z4=55.6%, ΣZ=(59.3%+55.9%+63.8%+55.6%) / 4=58.6%. The dynamic adjustment temperature field output duty cycle is 58.6%, so that the heating equipment can ensure the normal temperature field stable control and production quality.

[0119] In the above embodiment, by adding hardware and experimental measured data, it is shown that through current value judgment, the aging, short circuit, open circuit, solid-state breakdown and other abnormalities of the heating circuit components can be intelligently identified and the temperature field can be dynamically adjusted. Among them, the aging, short circuit, open circuit and solid-state breakdown of the heating tube can be intelligently identified through current value judgment, and the equipment early warning can be accurately output, which greatly shortens the time for troubleshooting and reduces the difficulty of abnormal handling; the heater loss can be intelligently identified and the temperature field can be dynamically adjusted to ensure the normal production of the equipment, thereby improving the production efficiency of the equipment and reducing the economic losses of customers.

[0120] In this embodiment, a temperature field dynamic adjustment device for selective laser sintering is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0121] This embodiment provides a temperature field dynamic adjustment device for selective laser sintering, such as Figure 7 As shown, including:

[0122] The control module 701 is used to control the PLC to output control signals with preset duty cycles to the heating circuits;

[0123] The abnormality judgment module 702 is used to obtain the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and judge the abnormality of the heating tube based on the current value of the heating circuit;

[0124] A calculation module 703 is used to calculate the power loss rate of the heating tube based on the current value of the heating circuit if the heating tube is in an abnormal state;

[0125] The dynamic adjustment module 704 is used to determine the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjust the temperature field based on the temperature field adjustment duty cycle.

[0126] In some optional implementations, the abnormality determination module 702 includes:

[0127] A solid-state breakdown judgment unit, used for obtaining a first heating current value of the heating circuit sent by the current acquisition module when the preset duty cycle is less than the judgment duty cycle, and comparing the first heating current value with the duty cycle current value. If the first heating current value is greater than the duty cycle current value, the heating tube is in a solid-state breakdown state;

[0128] The burnout judgment unit is used to obtain the second heating current value of the heating circuit sent by the current acquisition module when the preset duty cycle is greater than the judgment duty cycle, and compare the second heating current value with the duty cycle current value. If the second heating current value is less than the duty cycle current value, the heating tube is in a short circuit state or an open circuit state.

[0129] In some optional implementations, the abnormality determination module 702 further includes:

[0130] A determination unit, used for obtaining the actual current value of the heating circuit under the control signal of different preset duty cycles through the current acquisition module, and determining the current deviation based on the actual current value and the theoretical current value;

[0131] The aging judgment unit is used to compare the current deviation with a preset error range. If the current deviation does not match the preset error range, the heating tube is in an aging state.

[0132] In some optional implementations, the calculation module 703 is specifically used to obtain the heating tube power and the heating tube voltage, and calculate the heating tube power loss rate based on the current deviation, the heating tube power and the heating tube voltage.

[0133] In some optional embodiments, the method further comprises:

[0134] The comparison module is used to obtain the initial current value of the heating circuit sent by the current acquisition module when the heating device is in standby mode, and compare the initial current value with the duty cycle current value. If the initial current value is greater than / equal to the duty cycle current value, the heating tube is in a solid-state breakdown state.

[0135] In some optional implementations, the dynamic adjustment module 704 includes:

[0136] An acquisition unit, used for acquiring a default duty cycle of the temperature field, and determining an average value of the duty cycle based on the default duty cycle of the temperature field and a power loss rate of the heating tube;

[0137] The regulating unit is used to use the duty cycle average value as the temperature field regulating duty cycle, and dynamically regulate the temperature field using the temperature field regulating duty cycle.

[0138] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0139] In this embodiment, a temperature field dynamic adjustment device for selective laser sintering is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0140] The embodiment of the present invention also provides a computer device having the above Figure 7 A temperature field dynamic adjustment device for selective laser sintering is shown.

[0141] See also Figure 8 , Figure 8 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 8 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 10 is taken as an example.

[0142] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0143] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0144] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0145] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0146] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 8 The example of connecting through bus is taken in the following.

[0147] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0148] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0149] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0150] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for dynamically adjusting the temperature field for selective laser sintering, characterized in that: A host computer used in a heating device, wherein the heating device comprises the host computer, a PLC, a current acquisition module and a multi-channel heating circuit, the heating circuit is respectively connected to the PLC and the current acquisition module, and the host computer is connected to the PLC; the heating circuit comprises a solid-state relay and a heating tube, and the solid-state relay is connected to the heating tube; the method comprises: Controlling the PLC to output a control signal with a preset duty cycle to the heating circuit; Acquire the current value of the heating circuit sent by the current acquisition module under control signals with different preset duty cycles, and make an abnormality judgment on the heating tube based on the current value of the heating circuit; If the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit; The temperature field adjustment duty cycle is determined based on the power loss rate of the heating tube, and the temperature field is dynamically adjusted based on the temperature field adjustment duty cycle.

2. The method according to claim 1, characterized in that The obtaining of the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and performing abnormal judgment on the heating tube based on the current value of the heating circuit, comprises: When the preset duty cycle is less than the determined duty cycle, a first heating current value of the heating circuit sent by the current acquisition module is obtained, and the first heating current value is compared with the duty cycle current value. If the first heating current value is greater than the duty cycle current value, the heating tube is in a solid-state breakdown state; When the preset duty cycle is greater than the determined duty cycle, the second heating current value of the heating circuit sent by the current acquisition module is obtained, and the second heating current value is compared with the duty cycle current value. If the second heating current value is less than the duty cycle current value, the heating tube is in a short circuit state or an open circuit state.

3. The method according to claim 2, characterized in that The method of acquiring the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and judging the abnormality of the heating tube based on the current value of the heating circuit, further includes: Acquire the actual current value of the heating circuit under the control signal of different preset duty cycles through the current acquisition module, and determine the current deviation based on the actual current value and the theoretical current value; The current deviation is compared with a preset error range. If the current deviation does not conform to the preset error range, the heating tube is in an aging state.

4. The method according to claim 3, characterized in that If the heating tube is in an abnormal state, the power loss rate of the heating tube is calculated based on the current value of the heating circuit, including: The heating tube power and the heating tube voltage are obtained, and the heating tube power loss rate is calculated based on the current deviation, the heating tube power and the heating tube voltage.

5. The method according to claim 2, characterized in that: Before controlling the PLC to output control signals with preset duty ratios to the heating circuits respectively, the method further includes: When the heating device is in standby mode, the initial current value of the heating circuit sent by the current acquisition module is obtained, and the initial current value is compared with the duty cycle current value. If the initial current value is greater than / equal to the duty cycle current value, the heating tube is in a solid-state breakdown state.

6. The method according to claim 1, characterized in that The step of determining the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjusting the temperature field based on the temperature field adjustment duty cycle, includes: Obtaining a default duty cycle of the temperature field, and determining an average value of the duty cycle based on the default duty cycle of the temperature field and the power loss rate of the heating tube; The duty cycle average value is used as the temperature field adjustment duty cycle, and the temperature field is dynamically adjusted using the temperature field adjustment duty cycle.

7. A temperature field dynamic adjustment device for selective laser sintering, characterized in that: The upper computer used in the heating device comprises: A control module, used to control the PLC to output control signals with preset duty ratios to the heating circuits; An abnormality judgment module is used to obtain the current value of the heating circuit sent by the current acquisition module under the control signal of different preset duty cycles, and to judge the abnormality of the heating tube based on the current value of the heating circuit; a calculation module, configured to calculate a power loss rate of the heating tube based on a current value of the heating circuit if the heating tube is in an abnormal state; The dynamic adjustment module is used to determine the temperature field adjustment duty cycle based on the power loss rate of the heating tube, and dynamically adjust the temperature field based on the temperature field adjustment duty cycle.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the temperature field dynamic adjustment method for selective laser sintering according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the temperature field dynamic adjustment method for selective laser sintering according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the temperature field dynamic adjustment method for selective laser sintering according to any one of claims 1 to 6.

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