Infrared heating system for automobile repair

Abstract

The invention discloses an automobile repairing infrared heating system, which relates to the technical field of automobile paint surface repairing and curing and comprises a mounting frame, a heating plate mechanism, an automobile body, a lifting mechanism, an intelligent closed-loop temperature control system, a PLC (Programmable Logic Controller), an integrated digital operation platform and a safety interlocking system. Through the heating plate mechanism and the built-in catalyst layer, gas releases medium-wave infrared radiation after flameless combustion, the medium-wave infrared radiation directly acts on a repairing area, ineffective heating of air and automobile body metal in traditional hot air baking is avoided, the energy utilization rate is increased, meanwhile, the pulse controller adjusts the gas flow in real time according to a PLC instruction, and the energy utilization rate is increased. In combination with closed-loop feedback of the non-contact infrared temperature sensor, on-demand energy supply is realized, so that the comprehensive energy consumption is reduced, and the energy expenditure of an enterprise is directly reduced; the arranged lifting mechanism drives the top heating plate to adjust the height, and accurate moving adjustment of the heating plate mechanism is achieved through the X-axis moving guide rail and the Y-axis moving guide rail.

Description

Technical Field

[0001] This invention belongs to the field of automotive paint repair and curing technology, and in particular relates to an infrared heating system for automotive repair. Background Technology

[0002] Automotive paint repair curing refers to the process of subjecting the coating materials (including primer, color paint, clear coat, etc.) in the repair area to controlled physical or chemical treatment after the automotive paint surface has been damaged by external forces (such as scratches, dents, peeling, etc.). This process causes the materials to change from a liquid or semi-solid state to a solid state through solvent evaporation, resin cross-linking, molecular chain curing, etc., and forms a protective layer with specified hardness, adhesion, and weather resistance.

[0003] Currently, the automotive paint repair and curing process mainly relies on traditional hot air baking and conventional infrared heating technologies. Hot air baking achieves paint curing by heating the air in the drying chamber, requiring heating the air in the entire drying chamber and the large metal body of the vehicle. Most of the energy is consumed on non-target materials, resulting in low energy efficiency. Hot air convection leads to uneven heat distribution, with edges and corners of the vehicle heating up quickly (overheating), while large flat surfaces and dents heat up slowly, easily causing paint film defects such as orange peel, loss of gloss, and bubbles. The long preheating and curing cycle severely restricts production cycle and workstation turnover rate. Hot air flow easily carries dust, which adheres to the uncured paint surface, affecting the appearance quality. Conventional infrared heating is mostly controlled by simple switches or power regulators, resulting in imprecise temperature control and easy local overheating or underheating. The position and angle of the lamp or plate are fixed, making it impossible to adapt to the complex three-dimensional contours of different vehicle models and parts, making it difficult to guarantee uniformity. It heavily relies on the operator's experience to judge distance and time, resulting in large quality fluctuations and making it impossible to achieve standardized operation. Therefore, this invention proposes an infrared heating system for automotive repair. Summary of the Invention

[0004] This invention provides an infrared heating system for automotive repair. Through a specially designed heating plate mechanism, the built-in catalytic layer combustion gas releases mid-wave infrared radiation, directly acting on the repair area. This avoids the ineffective heating of air and vehicle body metal caused by traditional hot air baking, improving energy utilization. Simultaneously, a pulse controller adjusts the gas flow in real time according to PLC instructions, combined with closed-loop feedback from a non-contact infrared temperature sensor, achieving on-demand energy supply and reducing overall energy consumption, directly decreasing enterprise energy expenditure. A lifting mechanism drives the top heating plate for height adjustment, and precise movement adjustment of the heating plate mechanism is achieved through X-axis and Y-axis moving guides. A second servo motor drives the side heating plate deflection adjustment to adapt to the vehicle body's curved surface, avoiding time-consuming manual adjustments. Furthermore, an adaptive PID algorithm shortens the temperature adjustment response time, combined with a 15... The 0℃ catalytic layer preheating start-up design, along with the combustion fan delivering air to the catalytic layer surface through the sheet metal outlet of the top heating plate, accelerates gas combustion efficiency, promotes paint solvent evaporation, reduces baking cycle, increases first-pass yield, reduces rework rate, and saves significant material, labor, and management costs. The top heating plate and a pair of side heating plates form a "three-sided encircling" heating area, which, combined with a position detection laser sensor for real-time heating distance calibration, solves the problems of overheating at body corners and insufficient heating in dents, reducing orange peel and bubble defects. This improves the stability of the paint film in key indicators such as gloss, hardness, and adhesion, achieving factory standards. Furthermore, the process formula management module facilitates the transition from "experience-based operation" to "parametric standard operation," establishing a full-process data traceability system to ensure quality consistency and verifiability. In summary, these features address the problems mentioned in the background technology.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] An infrared heating system for automotive repair according to the present invention includes:

[0007] The system includes a mounting frame, a heating plate mechanism, a vehicle body, a lifting mechanism, an intelligent closed-loop temperature control system, a PLC controller, an integrated digital operating platform, and a safety interlock system. The heating plate mechanism and the lifting mechanism are both mounted on the mounting frame. The PLC controller and the integrated digital operating platform are both externally connected and electrically connected. The intelligent closed-loop temperature control system and the safety interlock system are both signal-connected to the PLC controller.

[0008] The heating plate mechanism includes a top heating plate and a pair of side heating plates. The top heating plate is located on the top of the vehicle body, and the pair of side heating plates are located on both sides of the vehicle body. Both the top heating plate and the side heating plates are provided with pressure equalization chambers. A gas flow equalization pipe is provided in the pressure equalization chamber, and a protective net is provided on the pressure equalization chamber. A pressure equalization layer is provided on the pressure equalization chamber, and filter cotton is provided on the pressure equalization layer and pressed on the protective net. A catalytic layer and an electric heating tube are respectively provided above the pressure equalization layer, and the electric heating tube is located between the pressure equalization layer and the catalytic layer.

[0009] Furthermore, a pair of combustion-supporting fans are installed on the top of the top heating plate, and an air outlet is cut out on the front side of the sheet metal of the top heating plate.

[0010] Furthermore, the lifting mechanism includes a first servo motor mounted on a mounting frame. A bidirectional lead screw is rotatably connected to the mounting frame via bearings, and the output end of the first servo motor is fixedly connected to one end of the bidirectional lead screw. The bidirectional lead screw is provided with a pair of external threads in opposite directions. Four pairs of sliding seats are slidably connected to the mounting frame, and a threaded moving seat is fixedly connected between the top pair of sliding seats. Each pair of threaded moving seats has a threaded through hole, and the threaded moving seat is threadedly connected to the bidirectional lead screw through the threaded through hole. A scissor rod is rotatably connected between the two pairs of sliding seats in the vertical direction via bearings and a rotating shaft.

[0011] Furthermore, the mounting bracket is fixedly connected to two pairs of slide rails, and four pairs of sliding seats are located within the two pairs of slide rails and are slidably connected to them.

[0012] Furthermore, the outer side of the mounting frame is provided with a pair of X-axis moving guide rails, and the outer wall of the mounting frame is fixedly connected with a pair of first connecting brackets, and each pair of first connecting brackets is fixedly connected with a plurality of first moving rollers. The plurality of first moving rollers are located inside the X-axis moving guide rails and are slidably connected to them.

[0013] Furthermore, a second connecting bracket is fixedly connected to the bottom end of each pair of first connecting brackets, a Y-axis moving guide rail is provided between the pair of X-axis moving guide rails, a plurality of second moving rollers are fixedly connected to the second connecting brackets, and the plurality of second moving rollers are located in the Y-axis moving guide rail and slidably connected to it, a second servo motor is fixedly connected to each pair of second connecting brackets, and a deflection connecting frame is fixedly connected to the top end of each pair of side heating plates, and the deflection connecting frame is fixedly connected to the output end of the second servo motor.

[0014] Furthermore, the intelligent closed-loop temperature control system includes three non-contact infrared temperature sensors, a position detection laser sensor, and a pulse controller. Adjustable brackets are fixedly connected between the outer walls of the non-contact infrared temperature sensors and the position detection laser sensor, and the three adjustable brackets are respectively installed on the top heating plate and a pair of side heating plates. The pulse controller is externally configured and is connected to the top heating plate and a pair of side heating plates respectively.

[0015] Furthermore, the PLC controller has a built-in adaptive PID control algorithm. The adaptive PID control algorithm dynamically adjusts the power signal output to the pulse controller based on the real-time temperature data fed back by the non-contact infrared temperature sensor, and is used for temperature control of the top heating plate and a pair of side heating plates. The adaptive PID control algorithm includes a PID parameter initial value tuning module, an adaptive triggering module, and an interference processing logic module. The integrated digital operation platform includes a human-machine interface, a process formula management module, a motion trajectory recall module, and a data recording and traceability module. The process formula management module stores multiple sets of process parameters, and the process parameters include motion trajectory coordinates, target temperature curve, PID initial value, and curing time.

[0016] Furthermore, the safety interlock system includes an emergency stop button, a gas leak sensor, a hardware over-temperature protector, and a safety relay. The emergency stop button, gas leak sensor, hardware over-temperature protector, and safety relay are all externally configured. The normally closed contacts of the emergency stop button, gas leak sensor, and hardware over-temperature protector are connected in series to the input circuit of the safety relay. The output terminal of the safety relay is connected to the enable circuit of the servo driver and the main gas solenoid valve.

[0017] The present invention has the following advantages over the prior art:

[0018] 1. Significantly optimized energy costs: This technical solution utilizes a heating plate mechanism with a built-in catalytic layer. After flameless combustion, the fuel gas releases mid-wave infrared radiation that directly acts on the repair area, avoiding the ineffective heating of air and metal body by traditional hot air baking, thus improving energy utilization. At the same time, the pulse controller adjusts the fuel gas flow in real time according to PLC instructions. Combined with the closed-loop feedback of the non-contact infrared temperature sensor, it achieves on-demand energy supply, reducing overall energy consumption and directly reducing the company's energy expenditure.

[0019] 2. Multi-dimensional contour heating + rapid temperature control response: This technical solution uses a lifting mechanism to adjust the height of the top heating plate, and uses X-axis and Y-axis moving guides to achieve precise movement adjustment of the heating plate mechanism. In conjunction with the second servo motor driving the deflection adjustment of the side heating plate, it adapts to the curved surface of the car body, avoiding the time-consuming manual adjustment. At the same time, the adaptive PID algorithm shortens the temperature adjustment response time. Combined with the 150℃ catalytic layer preheating start design, and the combustion fan blowing air to the surface of the catalytic layer through the sheet metal air outlet of the top heating plate, it not only accelerates the combustion efficiency of the fuel gas, but also promotes the evaporation of paint solvents, reduces the baking cycle, improves the first pass rate, reduces the rework rate, and saves a lot of material, labor time and management costs.

[0020] 3. Significantly improved paint quality and performance indicators: This technical solution forms a "three-sided encircling" heating area through a top heating plate and a pair of side heating plates. Combined with a position detection laser sensor to calibrate the heating distance in real time, it solves the problems of overheating at the edges of the car body and insufficient heating in dents. This reduces the rate of orange peel and bubble defects, and improves the stability of the paint film in key indicators such as gloss, hardness, and adhesion, meeting the original factory standards. Furthermore, through the process formula management module, it realizes the transformation from "experience-based operation" to "parametric standard operation", and establishes a full-process data traceability system to ensure quality consistency and verifiability.

[0021] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of an infrared heating system for automotive repair according to the present invention;

[0024] Figure 2 This is a rear view schematic diagram of the top heating plate in this invention;

[0025] Figure 3 This is a partial three-dimensional structural diagram of the side heating plate in this invention;

[0026] Figure 4 This is a three-dimensional structural diagram of the top heating plate and the lifting mechanism in this invention;

[0027] Figure 5 This is a partial three-dimensional structural diagram of an infrared heating system for automotive repair according to the present invention;

[0028] Figure 6 For the present invention Figure 5 Enlarged structural diagram at point A;

[0029] Figure 7 This is a partial disassembled structural diagram of an infrared heating system for automotive repair according to the present invention;

[0030] Figure 8 This is a three-dimensional structural diagram of the side heating plate, the second connecting bracket, and the second servo motor in this invention;

[0031] Figure 9 This is a system module diagram of the intelligent closed-loop temperature control system in this invention;

[0032] Figure 10 This is a system block diagram of the PLC controller and adaptive PID control algorithm in this invention;

[0033] Figure 11 This is a system module diagram of the integrated digital operation platform in this invention;

[0034] Figure 12 This is a system module diagram of the safety interlocking system in this invention;

[0035] Figure 13 This is a flowchart of the core operating mechanism of intelligent temperature control in this invention;

[0036] Figure 14 This is a flowchart of the decision-making logic in this invention.

[0037] The attached diagram lists the components represented by each number as follows:

[0038] 1. Mounting bracket; 2. Heating plate mechanism; 201. Top heating plate; 202. Side heating plate; 203. Pressure equalization chamber; 204. Gas flow equalization pipe; 205. Pressure equalization layer; 206. Filter cotton; 207. Catalytic layer; 208. Electric heating tube; 209. Protective net; 3. Vehicle body; 4. Combustion fan; 5. Lifting mechanism; 501. First servo motor; 502. Two-way lead screw; 503. Threaded moving seat; 504. Slide rail; 505. Sliding seat; 506. Scissor linkage; 6. First connecting bracket; 7. X-axis moving guide rail; 701. First moving roller; 8. Y-axis moving guide rail; 8 01. Second moving roller; 9. Second connecting bracket; 10. Adjustable bracket; 11. Non-contact infrared temperature sensor; 12. Position detection laser sensor; 13. Second servo motor; 14. Deflection connecting frame; 15. PLC controller; 1501. PID parameter initial value tuning module; 1502. Adaptive triggering module; 1503. Interference processing logic module; 16. Integrated digital operation platform; 1601. Human-machine interface; 1602. Process formula management module; 1603. Motion trajectory recall module; 1604. Data recording and traceability module; 17. Pulse controller. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be understood that the terms "relative", "one end", "inner", "lateral", "end", "both ends", "both sides", "front", "one end face", "the other end face", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention. Specific Implementation Example 1:

[0042] Please see Figures 1-14 As shown, an infrared heating system for automotive repair according to the present invention includes:

[0043] Mounting bracket 1, heating plate mechanism 2, vehicle body 3, lifting mechanism 5, intelligent closed-loop temperature control system, PLC controller 15, integrated digital operating platform 16, and safety interlock system. Heating plate mechanism 2 and lifting mechanism 5 are both mounted on mounting bracket 1. PLC controller 15 and integrated digital operating platform 16 are both externally connected and electrically connected. Intelligent closed-loop temperature control system and safety interlock system are both signal connected to PLC controller 15.

[0044] The heating plate mechanism 2 includes a top heating plate 201 and a pair of side heating plates 202. The top heating plate 201 is located on the top of the vehicle body 3, and the pair of side heating plates 202 are located on both sides of the vehicle body 3. Both the top heating plate 201 and the side heating plates 202 are provided with a pressure equalization chamber 203. A gas flow equalization pipe 204 is provided in the pressure equalization chamber 203, and a protective net 209 is provided on the pressure equalization chamber 203. A pressure equalization layer 205 is provided on the pressure equalization layer 205, and a filter cotton 206 is provided on the pressure equalization layer 205, with the filter cotton 206 pressing on the protective net 209. A catalytic layer 207 and an electric heating tube 208 are respectively provided above the pressure equalization layer 205, and the electric heating tube 208 is located between the pressure equalization layer 205 and the catalytic layer 207.

[0045] In the specific implementation process, the PLC controller 15 receives manual instructions (such as process selection) from the integrated digital operation platform 16 via electrical connection. Simultaneously, it acquires real-time data (temperature, location) from the intelligent closed-loop temperature control system and status signals (such as gas concentration) from the safety interlock system via signal connection. Then, it sends control instructions to each actuator. Natural gas enters the pressure equalization chamber 203 through the gas equalization pipe 204. The chamber structure of the pressure equalization chamber 203 transforms the gas from "single-point input" to "area diffusion," preventing excessively high or low local gas concentrations. The protective net 209 blocks external impurities from entering the pressure equalization chamber 203. The filter cotton 206 further filters tiny particles (such as dust and impurities) in the gas, preventing blockage or contamination of the catalyst layer 207. The heating tube 208 is first energized to heat the catalyst layer 207 to its activation temperature (approximately 150°C). (℃); then the gas passes through the equalization layer 205 (further equalizing the gas) and reaches the catalyst layer 207. The gas undergoes flameless combustion on the surface of the catalyst cotton layer the instant it comes into contact with the air, forming low-energy bases on the surface of the infrared plate catalyst cotton layer, generating vibrationally excited state products, and releasing energy in the form of infrared radiation. The medium wave generated has a very obvious heating effect on the carboxyl and hydroxyl groups in the coating. The catalyst layer 207 is the catalyst cotton layer. The catalyst cotton is the core functional layer of the infrared catalytic radiation plate in the infrared heating system for automotive paint repair. It is a special fiber material with mixed catalysts. Its manufacturing process is as follows: before the material is formed, the catalyst (such as platinum, palladium and other precious metal catalysts) is uniformly mixed into the fiber substrate. After special thickening treatment, a porous cotton-like carrier is formed for the flameless catalytic combustion of natural gas, converting chemical energy into infrared radiation energy of a specific wavelength.

[0046] Among them, a pair of combustion-supporting fans 4 are installed on the top of the top heating plate 201, and an air outlet is cut out on the front side of the sheet metal of the top heating plate 201.

[0047] The top heating plate 201 is installed facing downwards, and hot air easily adheres to the surface, leading to incomplete catalysis. After the combustion fan 4 (which adopts a fan and blade separate structure, which can effectively extend the motor life) is started, it delivers fresh air to the surface of the catalytic layer 207 through the air outlet, supplementing the oxygen required for combustion and avoiding "incomplete combustion caused by local oxygen deficiency". At the same time, the airflow from the air outlet blows evenly onto the paint surface, which on the one hand accelerates the evaporation rate of the paint solvent (such as water and organic solvents) and shortens the curing time; on the other hand, it makes the surface tension of the paint surface uniform and reduces the phenomenon of "sag" (streaks formed by paint dripping). Specific Implementation Example 2:

[0049] Please see Figure 1 , Figures 4-5 and Figures 7-8As shown, in a preferred embodiment, the lifting mechanism 5 includes a first servo motor 501 mounted on a mounting frame 1. A bidirectional lead screw 502 is rotatably connected to the mounting frame 1 via bearings, and the output end of the first servo motor 501 is fixedly connected to one end of the bidirectional lead screw 502. The bidirectional lead screw 502 is provided with a pair of external threads in opposite directions. Four pairs of sliding seats 505 are slidably connected to the mounting frame 1, and a threaded moving seat 503 is fixedly connected between the top pair of sliding seats 505. Each pair of threaded moving seats 503 has a threaded through hole, and the threaded moving seat 503 is threadedly connected to the bidirectional lead screw 502 through the threaded through hole. A scissor rod 506 is rotatably connected between the two pairs of sliding seats 505 in the vertical direction via bearings and a rotating shaft.

[0050] In the specific implementation process, the first servo motor 501 drives the bidirectional lead screw 502 to rotate. The reverse external thread of the bidirectional lead screw 502 causes a pair of threaded moving seats 503 to slide towards or away from each other (for example, when the bidirectional lead screw 502 rotates clockwise, the two threaded moving seats 503 move closer; when it rotates counterclockwise, the two threaded moving seats 503 move further apart). The scissor linkage 506 extends and retracts to adjust the height: the threaded moving seat 503 drives the top sliding seat 505 to slide along the slide rail 504, causing the distance between the two pairs of sliding seats 505 in the vertical direction to change, thereby driving the scissor linkage 506 to extend and retract (the distance decreases → the linkage rises, the distance increases → the linkage falls), and finally driving the top heating plate 201 to adjust the height.

[0051] The mounting bracket 1 is fixedly connected to two pairs of slide rails 504, and four pairs of sliding seats 505 are located in the two pairs of slide rails 504 and are slidably connected to them.

[0052] The slide rail 504 restricts the movement direction of the slide seat 505 to prevent the slide seat 505 from shifting and causing lifting jamming or tilting.

[0053] The mounting frame 1 has a pair of X-axis moving guide rails 7 on its outer side. The outer wall of the mounting frame 1 is fixedly connected to a pair of first connecting brackets 6, and each pair of first connecting brackets 6 is fixedly connected to a plurality of first moving rollers 701. The plurality of first moving rollers 701 are located inside the X-axis moving guide rails 7 and are slidably connected to them.

[0054] The first moving roller 701 of the first connecting bracket 6 slides along the X-axis moving guide rail 7, so that the mounting bracket 1 moves along the "body length direction" (such as the front of the car to the rear of the car), thereby driving the top heating plate 201 and a pair of side heating plates 202 to move synchronously.

[0055] Among them, the bottom ends of a pair of first connecting brackets 6 are fixedly connected to second connecting brackets 9, a Y-axis moving guide rail 8 is provided between a pair of X-axis moving guide rails 7, a plurality of second moving rollers 801 are fixedly connected to the second connecting brackets 9, and the plurality of second moving rollers 801 are located in the Y-axis moving guide rail 8 and are slidably connected to it, a second servo motor 13 is fixedly connected to a pair of second connecting brackets 9, and a deflection connecting frame 14 is fixedly connected to the top of a pair of side heating plates 202, and the deflection connecting frame 14 is fixedly connected to the output end of the second servo motor 13.

[0056] The second moving roller 801 of the second connecting bracket 9 slides along the Y-axis moving guide rail 8, so that the mounting bracket 1 moves along the "body width direction" (such as left-right). In conjunction with the X-axis movement, the heating plate mechanism 2 covers any flat area of ​​the body. At the same time, the second servo motor 13 drives the deflection connecting bracket 14 to rotate, which drives the side heating plate 202 to rotate around the Z-axis to adapt to the body surface (such as the door curvature, bumper curvature) and avoid the time-consuming manual adjustment. Specific Implementation Example 3:

[0058] Please see Figure 1 and Figures 9-14 As shown, in a preferred embodiment, the intelligent closed-loop temperature control system includes three non-contact infrared temperature sensors 11, a position detection laser sensor 12, and a pulse controller 17. An adjustable bracket 10 is fixedly connected between the outer walls of the non-contact infrared temperature sensors 11 and the position detection laser sensor 12, and the three adjustable brackets 10 are respectively installed on the top heating plate 201 and a pair of side heating plates 202. The pulse controller 17 is externally connected and is connected to the top heating plate 201 and the pair of side heating plates 202 respectively.

[0059] In the specific implementation process, three non-contact infrared temperature sensors 11 (corresponding to the top heating plate 201 and a pair of side heating plates 202) collect the paint surface temperature in real time (accuracy ±1℃), the position detection laser sensor 12 collects the distance between the heating plate and the vehicle body (accuracy ±0.5mm), the adjustable bracket 10 adjusts the sensor angle to ensure that the data collection covers the target area, and the adaptive PID control algorithm dynamically calculates and outputs analog signals to the gas pulse controller 17 based on the real-time temperature feedback from the infrared sensors to achieve precise and pulsed power adjustment.

[0060] The PLC controller 15 has a built-in adaptive PID control algorithm. The adaptive PID control algorithm dynamically adjusts the power signal output to the pulse controller 17 based on the real-time temperature data fed back by the non-contact infrared temperature sensor 11, and is used for temperature control of the top heating plate 201 and a pair of side heating plates 202. The adaptive PID control algorithm includes a PID parameter initial value tuning module 1501, an adaptive trigger module 1502, and an interference processing logic module 1503. The integrated digital operation platform 16 includes a human-machine interface 1601, a process formula management module 1602, a motion trajectory recall module 1603, and a data recording and traceability module 1604. The process formula management module 1602 stores multiple sets of process parameters, including motion trajectory coordinates, target temperature curve, PID initial value, and curing time.

[0061] In practical implementation, this solution achieves precise temperature control through the development and application of an adaptive PID control algorithm. The precise temperature control of this system is based on the following three progressively layered technical levels:

[0062] 1. Tuning the initial values ​​of PID parameters

[0063] The initial PID parameters are the basis for the system's first startup or process changeover. We use a combination of "model-based simulation tuning" and "empirical database" to obtain them.

[0064] Theoretical basis (Ziegler-Nicholas Method II):

[0065] First, the dynamic characteristics of the system are obtained through the system's step response: the equivalent lag time τ and the equivalent time constant T. Then, the initial PID parameters are calculated using the classic Zn empirical formula.

[0066] Project Implementation:

[0067] Simulation modeling: A thermodynamic model of the heating system (including gas pulse burner, radiant panel, and vehicle body paint) is established in MATLAB / Simulink, and preliminary PID parameters are obtained quickly and safely through simulation.

[0068] Experience Database: The system database stores a set of validated and optimized initial PID parameters for each combination of vehicle model, paint type, and repair area. When the operator selects a process formula, the system automatically calls the corresponding parameter set, thus skipping the rough initial tuning phase and achieving a fast and stable start-up.

[0069] 2. Triggering conditions for "adaptive"

[0070] The adaptive mechanism is not continuously running, but is triggered under specific conditions to balance system response and computational load. The main triggering conditions include:

[0071] Condition 1: Performance indicators exceed the threshold.

[0072] This is triggered when a certain performance indicator of temperature error continuously exceeds a set threshold.

[0073] Condition 2: Operating condition identification and switching

[0074] The system automatically triggers when it detects a significant change in the operating state: a large step change in the setpoint (SP) (such as from 40°C to 60°C); or the system detects a sudden change in the characteristics of the controlled object, for example, by monitoring the real-time response curve, it finds that the equivalent τ and T have changed (this may be because the car door has been switched from a heated metal door to a plastic bumper).

[0075] Condition 3: Periodic self-learning

[0076] During system idle or maintenance periods, a small test signal is automatically run, and the PID parameters are readjusted based on the response curve to achieve parameter "evolution".

[0077] 3. Interference handling logic

[0078] The system employs layered processing logic to address different types of interference:

[0079] Front-end anti-interference design (prevention):

[0080] Input signal filtering: The raw signal from the infrared temperature sensor is filtered using an α-β-γ filter or a moving average filter to remove high-frequency noise and prevent the differential term from being amplified.

[0081] Differential-first (differential term only affects the measured value PV): Prevents sudden jumps in the differential term from impacting the system when the setpoint changes.

[0082] Core algorithm for anti-interference (suppression):

[0083] Trigger: When the controller output remains at the limit value (such as 100% or 0%) and the error is not eliminated.

[0084] Action: Pause the integration process, or clamp the integral term to the current value to prevent the integrator from accumulating indefinitely, thus enabling a rapid response when the error reverses.

[0085] Setpoint weighting: Setpoint weights b and c are introduced into the proportional and differential terms to soften the impact of setpoint changes.

[0086] "Adaptive" response to interference (compensation): The core of this system's adaptive mechanism lies in the "fuzzy rule base".

[0087] Example of a rule:

[0088] The IF temperature is rising rapidly, THEN is decreasing significantly, and Td is being strengthened (to prevent overshoot).

[0089] If IF is in the medium range and the error remains positive (i.e., the temperature never reaches the set value), then Ti is moderately reduced (to enhance the integral action and eliminate steady-state error).

[0090] If the IF system detects continuous, high-frequency small fluctuations, THEN appropriately decreases Kp and increases Td (to suppress oscillations and improve stability).

[0091] This solution employs upper-level human-computer interaction (HMI) software development, process formula database management, and IoT technology for data acquisition and remote operation and maintenance.

[0092] Furthermore, the adaptive PID algorithm in this solution is intelligent because it surpasses traditional PID algorithms by dynamically adjusting based on real-time conditions. The working principle of its core rule base is as follows:

[0093] Assuming the current temperature is 45℃, the target is 60℃.

[0094] Scenario 1: Rapid temperature rise period (error > 10℃)

[0095] Phenomenon: The error e is very large.

[0096] Algorithm decision: Employs a "fast-paced" strategy. Rule base output: Significantly increase Kp (proportional action) and limit the integral Ii, causing the heater to operate at full or high power to quickly approach the target.

[0097] Scenario 2: Approaching the target, preventing overshoot (error decreases, but descent speed becomes too fast)

[0098] Phenomenon: The error e decreases, but the error change rate de / dt is negative and very large (the temperature rises too quickly).

[0099] Algorithm decision: Employs a "precise braking" strategy. Rule base output: Decisively reduce Kp and introduce the derivative Td in advance, reducing the heating power like "point braking" to smoothly approach the target value and avoid overshooting.

[0100] Scenario 3: Stable heat preservation period (error fluctuates within ±2℃)

[0101] Phenomenon: The error e is very small, but it may fluctuate between positive and negative.

[0102] Algorithm decision: Employs a "micro-management stabilization" strategy. Rule base output: Decrease Kp to avoid oscillations, appropriately increase Ii (integral action) to completely eliminate static errors, and ensure that the temperature is stably locked at the set value.

[0103] This system transforms the uncontrollable, experience-dependent baking process into a predictable, quantifiable, and repeatable precision industrial process through a real-time closed loop of "perception-decision-execution." It not only maintains stable temperature but also precisely controls how the temperature changes over time—this is its "intelligence" and the fundamental reason why it can guarantee perfect paint curing.

[0104] 3. Integrated digital operation platform:

[0105] This system creates an intelligent hub integrating process management, motion control, and data traceability. Through a built-in process database, complex operations are simplified into "one-click" intelligent decision-making and fully automated execution. The process database is not a simple list, but a structured set of parameters, where each "process recipe" uniquely corresponds to a combination of [vehicle model - repair area - paint code].

[0106] The specific parameters it stores are divided into three main categories:

[0107] 1. Motion trajectory parameters

[0108] Includes: Track number; an array of critical path point coordinates for all servo axes on the path; motion velocity curve configuration; motion acceleration curve configuration.

[0109] 2. Temperature control parameters

[0110] Includes: target temperature-time curve (stored as a series of (time, temperature) data points); optimized PID parameters corresponding to this formula; and the maximum allowable heating power for this part.

[0111] 3. Materials and Safety Parameters

[0112] Includes: Paint type (water-based / solvent-based); Total curing time; Recommended cooling rate.

[0113] The essence of "one-click intelligent decision-making" is an automatic parameter calling and execution process based on condition matching.

[0114] The safety interlock system includes an emergency stop button, a gas leak sensor, a hardware over-temperature protector, and a safety relay. The emergency stop button, gas leak sensor, hardware over-temperature protector, and safety relay are all externally connected. The normally closed contacts of the emergency stop button, gas leak sensor, and hardware over-temperature protector are connected in series to the input circuit of the safety relay. The output terminal of the safety relay is connected to the enable circuit of the servo driver and the main gas solenoid valve.

[0115] The safety interlocking system is designed in accordance with the principles of "redundancy, independence, and multi-level", and has built a comprehensive safety protection system from hardware to software and from active prevention to passive protection.

[0116] The safety interlock system includes three lines of defense:

[0117] The first line of defense: emergency shutdown and hazard prevention devices, which are used to immediately interrupt the process before or when a hazard occurs; including:

[0118] 1. Emergency stop device

[0119] 2. Area protection device (install a safety light curtain; if any personnel enter, all movement and heating will be immediately stopped, and an audible and visual alarm will be triggered).

[0120] 3. Gas safety detection device (gas leak sensor, gas pressure protection switch, back temperature thermocouple: real-time monitoring of heater status, immediate shutdown of solenoid valve when the temperature drops below the safe level)

[0121] The second line of defense: process safety and over-limit protection devices, used to prevent system parameters from exceeding safe ranges, including:

[0122] 1. Temperature protection: Each heating plate is equipped with an infrared temperature sensor and a position sensor. If the temperature exceeds the workpiece's heating temperature range, the heating can be stopped immediately or switched to low power heating.

[0123] 2. Motion safety protection: A mechanical limit switch is designed at the physical end of the guide rail travel, and a software limit switch is set in the PLC controller. The movement will decelerate and stop before it exceeds the range.

[0124] 3. Electrical safety protection: Circuit breakers, fuses, and thermal relays are installed to protect the circuit from damage; residual current devices are installed to prevent electric shock.

[0125] The third line of defense: security control logic, where all devices are integrated through a rigorous control logic;

[0126] 1. Hard-wired safety circuit: The normally closed contacts of the emergency stop button, safety light curtain, gas leak sensor, hardware over-temperature protector, and flame fault signal are connected in series with the input circuit of the safety relay. When any condition is triggered, the circuit breaks, and the safety relay physically cuts off the power supply to the servo drive and the main gas solenoid valve. This circuit is completely independent of the PLC, offering the fastest response and highest reliability.

[0127] 2. PLC software safety logic: includes interlocks (heating cannot proceed if the safety door is not closed, etc.).

[0128] Sequential control (ventilation and purging first, then ignition; gas shut-off first, then cooling) when starting up.

[0129] Status monitoring and alarms (continuously monitors the status of all sensors; any abnormality will display specific alarm information on the HMI and be logged).

[0130] 3. Reset and Restart Logic

[0131] After any safe shutdown (especially hard-wired circuit triggering), the system must be manually reset;

[0132] Before resetting, the cause of the alarm must be identified and cleared on the HMI to prevent operation with the faulty device.

[0133] In the specific implementation process, the first stage is: building the core hardware platform and developing basic drivers.

[0134] The goal of this stage is to build the basic physical architecture and core driving units of the system, and to achieve basic "dynamic, thermal, and measurable" capabilities.

[0135] 1.1 Integration of the core mechanical motion platform:

[0136] 1.1.1 Complete the installation and mechanical leveling of the high-rigidity frame, servo motor, linear module, and rotary platform.

[0137] 1.1.2 Connect all servo drives to the Siemens PLC's PROFINET network, complete the configuration and basic jog testing in TIAPortal, and ensure precise and smooth single-axis motion.

[0138] 1.2 Core Thermal Energy System Integration: The start / stop, fault alarm, and power regulation signals of the pulse controller are physically connected to the I / O modules and analog output modules of the Siemens PLC.

[0139] 1.3 Deployment of the core sensing system: Install a non-contact infrared temperature sensor and connect its signal to the analog input module of the PLC.

[0140] Phase Two: Implementation of Control Logic and Security Systems

[0141] The goal of this phase is to inject a "nervous system" into the hardware platform, with a focus on implementing complex cooperative motion logic and crucial safety interlocks.

[0142] 2.1 Motion control program development: A multi-axis collaborative motion control program was written in the Siemens PLC to realize the complex "contour motion" trajectory planning of the heating plates on both sides and the top.

[0143] This system adopts a collaborative control strategy of "zone triggering and on-demand movement" to achieve efficient and precise contour heating.

[0144] 1. Initial state and coordinate system

[0145] Initial position: The side plates are stopped at both ends of the guide rails, the top plate is raised to the highest point, and the system is in a safe standby state.

[0146] Coordinate systems: Establish a world coordinate system (based on the ground fixture), a tool coordinate system (centered on the heating plate), and a user coordinate system (based on the vehicle body features) to provide a unified spatial reference for all movements.

[0147] 2. Partition-triggered collaborative logic

[0148] Core principle: Each heating plate unit responds to commands independently.

[0149] Action Trigger:

[0150] Baking side: Only the heating plate 202 on this side is triggered, causing it to move along the guide rail and adaptively rotate to the preset contour trajectory.

[0151] Baking the front / rear of the vehicle: Trigger the side heating plate 202 on the corresponding side to perform a rotation action at a specific angle to cover the front or rear curved surface.

[0152] Bake Top: Triggers the top heating plate to descend to the preset working height.

[0153] The synergy is reflected in the fact that multiple boards in the same area (such as on the left) maintain synchronous movement within their local area to avoid interference.

[0154] 3. Trajectory Planning and Interpolation

[0155] Teaching programming: For each repairable area of ​​each vehicle model, a set of independent critical path points (including spatial coordinates and rotation angles) are pre-taught and recorded.

[0156] B-spline interpolation: During motion, the controller uses these path points to perform B-spline curve interpolation, generating a smooth and continuous three-dimensional motion trajectory to ensure that the heating plate maintains the optimal relative posture with the vehicle body surface during movement and rotation.

[0157] 4. Security Logic

[0158] The system monitors the position of all motion axes in real time and uses a dynamic anti-collision algorithm to ensure that the heating plate and the vehicle body, as well as the heating plate itself, maintain a safe distance at all times.

[0159] This solution replaces complex overall linkage with independent control of zones, achieves three-dimensional contouring through precise trajectory interpolation, and ultimately realizes precise and uniform heating of specific areas of the vehicle body in the most efficient way while ensuring safety.

[0160] 2.2 Safety Interlock Program Development:

[0161] 2.2.1 Write rigorous safety logic to hard-lock all safety signals, such as emergency stop buttons, gas leak sensors, and hardware over-temperature protectors, with the servo drive enable actuators to build a safety protection system with the highest priority.

[0162] 1. Definition of safety signals

[0163] Gas leak: refers to a gas concentration sensor detecting that the concentration of combustible gas exceeds 25% of the lower explosive limit (LEL).

[0164] Hardware over-temperature: Independent mechanical temperature control switch, set to 95°C as the maximum hardware limit.

[0165] Hard-wired safety circuit

[0166] 2. Core component: Safety relay.

[0167] Connection method: Connect the emergency stop button, gas sensor, normally closed contact of over-temperature protector, and input circuit of safety relay in series to form an independent safety chain.

[0168] Action: When any safety signal is triggered, the output of the safety relay will be immediately and physically cut off, thus forcibly disconnecting the relay.

[0169] Servo driver enable circuit (stops all movement)

[0170] Gas main solenoid valve powered (gas supply cut off)

[0171] Features: This circuit is completely independent of the PLC software, has the fastest response, the highest priority, and ensures intrinsic safety.

[0172] 3. Collaboration with PLC

[0173] The PLC monitors the status feedback signals of the safety relays to provide fault alarms and lock the system status, but does not participate in emergency shutdown control.

[0174] This design ensures that even in the most extreme circumstances (such as a PLC crash), a safe shutdown can still be achieved through hardware linkage, completely eliminating safety hazards.

[0175] 2.3 Basic Human-Machine Interface (HMI) Development: Develop an HMI interface for manual mode debugging to enable individual control of each axis, manual start and stop of the burner, and monitoring of critical status.

[0176] The third stage is the integration of intelligent control algorithms and software platforms. The goal of this stage is to equip the system with a "brain" to realize the core functions of intelligence and automation.

[0177] 3.1 Implementation of Thermal Energy Closed-Loop Control Algorithm:

[0178] A temperature closed-loop control algorithm was developed and implemented using the process objects or advanced algorithm library of Siemens PLCs. This algorithm dynamically calculates and outputs an analog signal to the gas pulse controller based on the real-time temperature feedback from the infrared sensor, achieving precise, pulse-based power regulation.

[0179] 3.2 Deployment of the upper-layer intelligent software platform:

[0180] Complete the deployment of HMI / SCADA software, integrating the process recipe management system (storing heating parameters for different vehicle models), motion trajectory recall module, and data recording and traceability module.

[0181] Phase 4: System verification and process parameter solidification. The goal of this phase is to conduct final verification and optimization of the entire system to ensure that it meets actual production requirements.

[0182] 4.1 System integration and performance testing:

[0183] Conduct no-load and load linkage tests on the whole machine to optimize the coordination and response speed of "motion-heating" control, and verify temperature uniformity and control accuracy.

[0184] 4.2 Actual vehicle process verification and parameter solidification:

[0185] 4.2.1 Conduct actual spraying and curing tests on experimental vehicles, and use professional instruments to inspect the quality of the paint film.

[0186] 4.2.2 Based on the test results, the optimal motion trajectory, temperature curve and gas power curve for different vehicle models and different paints are solidified in the system's process formula database to form a standardized operating procedure.

[0187] The circuits, electronic components, and chip modules involved in this invention are all existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this invention does not involve improvements to the software and methods.

[0188] All standard parts used in the application documents can be purchased from the market. All components in this application document can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. All electrical components mentioned in this document are electrically connected to an external power source.

[0189] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An infrared heating system for automotive repair, characterized in that, include: Mounting frame (1), heating plate mechanism (2), vehicle body (3), lifting mechanism (5), intelligent closed-loop temperature control system, PLC controller (15) and integrated digital operation platform (16) and safety interlock system, the heating plate mechanism (2) and lifting mechanism (5) are both mounted on mounting frame (1), the PLC controller (15) and integrated digital operation platform (16) are both externally mounted, and the PLC controller (15) and integrated digital operation platform (16) are electrically connected, the intelligent closed-loop temperature control system and safety interlock system are both signal connected to PLC controller (15); The heating plate mechanism (2) includes a top heating plate (201) and a pair of side heating plates (202). The top heating plate (201) is located on the top of the vehicle body (3), and the pair of side heating plates (202) are located on both sides of the vehicle body (3). Both the top heating plate (201) and the side heating plates (202) are provided with a pressure equalization chamber (203). A gas flow equalization pipe (204) is provided in the pressure equalization chamber (203). A protective net (209) is provided on the cavity (203), and a pressure equalization layer (205) is provided on the pressure equalization cavity (203). A filter cotton (206) is provided on the pressure equalization layer (205), and the filter cotton (206) is pressed on the protective net (209). A catalyst layer (207) and an electric heating tube (208) are respectively provided above the pressure equalization layer (205), and the electric heating tube (208) is located between the pressure equalization layer (205) and the catalyst layer (207).

2. The automotive repair infrared heating system according to claim 1, characterized in that, A pair of combustion-supporting fans (4) are installed on the top of the top heating plate (201), and an air outlet is cut out on the front side of the sheet metal of the top heating plate (201).

3. The automotive repair infrared heating system according to claim 1, characterized in that, The lifting mechanism (5) includes a first servo motor (501) mounted on a mounting frame (1). A bidirectional lead screw (502) is rotatably connected to the mounting frame (1) via a bearing. The output end of the first servo motor (501) is fixedly connected to one end of the bidirectional lead screw (502). The bidirectional lead screw (502) is provided with a pair of external threads in opposite directions. Four pairs of sliding seats (505) are slidably connected to the mounting frame (1). A threaded moving seat (503) is fixedly connected between the top pair of sliding seats (505). Each pair of threaded moving seats (503) has a threaded through hole. The threaded moving seat (503) is threadedly connected to the bidirectional lead screw (502) via the threaded through hole. A scissor rod (506) is rotatably connected between the two pairs of sliding seats (505) in the vertical direction via a bearing and a rotating shaft.

4. The automotive repair infrared heating system according to claim 3, characterized in that, The mounting bracket (1) is fixedly connected to two pairs of slide rails (504), and four pairs of sliding seats (505) are located in the two pairs of slide rails (504) and are slidably connected to them.

5. The automotive repair infrared heating system according to claim 1, characterized in that, The mounting bracket (1) has a pair of X-axis moving guide rails (7) on its outer side. The outer wall of the mounting bracket (1) is fixedly connected to a pair of first connecting brackets (6), and each pair of first connecting brackets (6) is fixedly connected to a plurality of first moving rollers (701). The plurality of first moving rollers (701) are located inside the X-axis moving guide rails (7) and are slidably connected to them.

6. The automotive repair infrared heating system according to claim 5, characterized in that, A second connecting bracket (9) is fixedly connected to the bottom of each pair of first connecting brackets (6). A Y-axis moving guide rail (8) is provided between the pair of X-axis moving guide rails (7). Multiple second moving rollers (801) are fixedly connected to the second connecting brackets (9), and the multiple second moving rollers (801) are all located in the Y-axis moving guide rail (8) and are slidably connected to it. A second servo motor (13) is fixedly connected to each pair of second connecting brackets (9). A deflection connecting frame (14) is fixedly connected to the top of each pair of side heating plates (202), and the deflection connecting frame (14) is fixedly connected to the output end of the second servo motor (13).

7. The automotive repair infrared heating system according to claim 1, characterized in that, The intelligent closed-loop temperature control system includes three non-contact infrared temperature sensors (11), a position detection laser sensor (12), and a pulse controller (17). An adjustable bracket (10) is fixedly connected between the outer walls of the non-contact infrared temperature sensors (11) and the position detection laser sensor (12). The three adjustable brackets (10) are respectively installed on the top heating plate (201) and a pair of side heating plates (202). The pulse controller (17) is externally connected and is connected to the top heating plate (201) and the pair of side heating plates (202).

8. The automotive repair infrared heating system according to claim 7, characterized in that, The PLC controller (15) has a built-in adaptive PID control algorithm. The adaptive PID control algorithm dynamically adjusts the power signal output to the pulse controller (17) based on the real-time temperature data fed back by the non-contact infrared temperature sensor (11), and is used for the temperature control of the top heating plate (201) and a pair of side heating plates (202). The adaptive PID control algorithm includes a PID parameter initial value tuning module (1501), an adaptive triggering module (1502), and an interference processing logic module (1503). The integrated digital operation platform (16) includes a human-machine interface (1601), a process formula management module (1602), a motion trajectory calling module (1603), and a data recording and traceability module (1604). The process formula management module (1602) stores multiple sets of process parameters, and the process parameters include motion trajectory coordinates, target temperature curve, PID initial value, and curing time.

9. The automotive repair infrared heating system according to claim 1, characterized in that, The safety interlock system includes an emergency stop button, a gas leak sensor, a hardware over-temperature protector, and a safety relay. The emergency stop button, gas leak sensor, hardware over-temperature protector, and safety relay are all externally connected. The normally closed contacts of the emergency stop button, gas leak sensor, and hardware over-temperature protector are connected in series to the input circuit of the safety relay. The output terminal of the safety relay is connected to the enable circuit of the servo driver and the main gas solenoid valve.

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