Electric furnace molten steel temperature sampling robot measuring point position control method

Abstract

A kind of electric furnace molten steel temperature sampling robot's measuring point position control method, within the range of electric furnace body's inclination limit, according to the actual inclination of electric furnace, the trajectory of robot measuring gun is determined in the furnace temperature sampling, according to this trajectory and in combination with the position information when measuring gun reaches molten pool liquid level, the advancement of robot measuring gun to target measuring point and the temperature measurement of measuring gun to target measuring point are completed.The electric furnace molten steel temperature sampling robot's measuring point position control method of the application makes the electric furnace temperature sampling robot carrying measuring gun into the furnace measurement operation more intelligent, can be adjusted according to the angle of electric furnace body, the dynamic furnace condition such as height of liquid steel in the furnace, and adaptively adjust measuring point position, to improve the accuracy and reliability of robot measuring gun insertion molten steel liquid level measurement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metallurgical steelmaking automatic control and intelligent robot control, and particularly relates to a measuring point position control method for a molten steel temperature sampling robot of an electric furnace. BACKGROUND

[0002] In the steelmaking operation process, molten steel temperature sampling, as an important detection means to ensure the quality of the smelting process, is widely used in many operation links such as steelmaking, refining, continuous casting, etc. The temperature sampling operation is faced with high temperature, splashing, dust and other harsh environmental factors in the molten metal melting area. The electric furnace molten steel temperature sampling operation is located at the furnace door, and the operation environment is particularly harsh. For a long time, the molten steel temperature sampling operation is completed by manual operation, which has high labor load and high risk and instability. With the development of robot technology, the robot operation system has been gradually applied to replace the manual temperature sampling operation in the steelmaking field, and is continuously expanding the application range.

[0003] The main task of the robot temperature sampling is to automatically obtain accurate temperature measurement results and qualified samples of the molten steel in the furnace. One of the keys to achieve this goal is how to insert the temperature sampling gun along the appropriate trajectory into the furnace, accurately insert it into the best position below the molten pool of the molten steel in the furnace without collision, so as to ensure the appropriate depth and obtain accurate measurement results. If collision occurs or the measuring point is too deep, the measuring gun is easy to be damaged, and if the measuring point is too shallow, the measurement result is easy to be inaccurate.

[0004] The temperature sampling port of the electric furnace steelmaking is generally located at the side of the furnace door, and there is a large diameter electrode at the top, and the furnace cover is in the off state. The electric furnace manual temperature sampling operation mainly relies on experience to master the measuring point position and depth, which has great uncertainty, and sometimes leads to too large temperature measurement error, resulting in repeated measurement. At present, the steel plants using robot temperature sampling basically adopt the control method of fixed trajectory and measuring point position. This method has the risk of uncertainty of measuring point depth for the electric furnace with large changes in the amount of molten steel in the furnace, changes in the inclination angle of the furnace body during smelting, large changes in the liquid level of the molten pool, and large changes in the thickness of the refractory in the furnace, which is easy to cause abnormality such as measuring gun burning and inaccurate measurement, affecting the detection reliability and stability of the system.

[0005] The application number is: CN 201510126842.6, the invention application discloses "a kind of full-automatic molten steel temperature sampling device", including rotating base, gun rack, trolley, gun body, first motor, second motor, laser range finder, storage bin, recovery bin and control console;Trolley is arranged on gun rack, first motor is connected with trolley by transmission mechanism, gun rack is connected with rotating base by swing mechanism, second motor is connected with rotating base;Gun body is fixed on trolley, telescopic gun head is provided on gun body, gun head can be matched with probe, laser range finder is fixed on gun body;Storage bin and recovery bin are respectively provided with multiple storage positions for storing new probe and recovery positions for recovering old probe, and storage positions and recovery positions are arranged near rotating base;First motor, second motor and laser range finder are connected with control console respectively.

[0006] The application number is: CN 201010288862.0, the invention application discloses "a kind of molten steel accurate temperature sampling system and method thereof", including intelligent robot system, automatic temperature sampling gun system, liquid level detection device and industrial control computer, the whole system is controlled by industrial computer, first, liquid level detection device determines the depth of molten steel liquid level, then intelligent robot is responsible for installing probe, finally, automatic gun realizes automatic temperature sampling.The advantage is that through infrared molten steel liquid level measurement and servo position control, accurate positioning of each gun temperature measurement and sampling is realized, and the system accidental error caused by manual measurement mode to measurement result is completely eliminated, which provides reliable guarantee for improving the control and precision of molten steel quality.

[0007] The application number is: CN 201810229602.2, the invention application discloses "a kind of method for automatically measuring temperature and / or sampling at converter steelmaking furnace", the method adopts automatic temperature measurement and sampling system at converter steelmaking furnace to measure temperature and / or sample, the system includes automatic temperature measurement and sampling part at furnace front, sleeve automatic disassembly part and system electric control part;The sleeve automatic disassembly part is composed of robot and its gripper, sleeve magazine, molten steel sample and waste sleeve collection bin and machine vision system;The machine vision system measures the position of actual temperature measurement gun and / or sampling gun head, compares with the preset coordinates of temperature measurement gun and / or sampling gun, calculates the deformation of temperature measurement gun and / or sampling gun head, and provides the deformation to robot, so that robot controls the displacement of gripper according to the deformation, and accurately installs each sleeve. SUMMARY

[0008] To solve the above problems, the present application provides a kind of electric furnace molten steel temperature sampling robot measuring point position control method

[0009] A kind of electric furnace molten steel temperature sampling robot measuring point position control method, characterized in that:

[0010] Within the inclination limit of the electric furnace body, the robot gun's entry furnace temperature measuring sampling track is determined according to the actual inclination of the electric furnace, and according to the track and the position information when the gun reaches the molten pool liquid surface, the robot gun is sent to the target measuring point and the gun measures the temperature of the target measuring point.

[0011] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0012] The robot gun's entry furnace temperature measuring track is determined by the position of the following key points:

[0013] The reaching furnace mouth position, the entering furnace position and the reaching molten pool upper position.

[0014] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0015] A temperature sensing probe is arranged at the end of the robot gun, and a temperature measuring instrument is established accordingly. Through the subprogram arranged in cooperation with the temperature measuring instrument, the determination of whether the gun reaches the molten pool liquid surface is established by calling the subprogram through the main program.

[0016] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0017] The position information when the gun reaches the molten pool liquid surface and the sending of the robot gun to the target measuring point are combined, specifically:

[0018] When the gun reaches the molten pool liquid surface, the three-dimensional position coordinates of the robot gun at this moment are recorded, and the Z-direction information of the three-dimensional position coordinates is summed with the target depth to form the Z-direction information of the target measuring point. The three-dimensional position information of the target measuring point of the gun is established by combining the X and Y information in the three-dimensional position coordinate information when the robot gun reaches the molten pool liquid surface, and the sending of the gun is completed according to the three-dimensional position information.

[0019] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0020] The key points also include the following:

[0021] The standby position, the directly opposite furnace mouth position and the near furnace mouth position.

[0022] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0023] The key points also include the reaching deepest measuring point position.

[0024] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the key points include:

[0025] The position of reaching the furnace mouth position, the position of entering the furnace position, and the position of reaching the position above the molten pool are determined according to the following:

[0026] P3 = P3 min + (P3 max -P3 min ) × T

[0027] P4 = P4 min + (P4 max -P4 min ) × T

[0028] P5 = P5 min + (P5 max -P5 min ) × T

[0029] In the above formula,

[0030] P3: the actual coordinate value of reaching the furnace mouth position;

[0031] P4: the actual coordinate value of entering the furnace position;

[0032] P5: the actual coordinate value of reaching the position above the molten pool

[0033] P3 min : the coordinate value of reaching the furnace mouth position when the lower limit of the inclination angle of the electric furnace body is reached;

[0034] P3 max : the coordinate value of reaching the furnace mouth position when the upper limit of the inclination angle of the electric furnace body is reached;

[0035] P4 min : the coordinate value of entering the furnace position when the lower limit of the inclination angle of the electric furnace body is reached;

[0036] P4 max : the coordinate value of entering the furnace position when the upper limit of the inclination angle of the electric furnace body is reached;

[0037] P5 min : the coordinate value of reaching the position above the molten pool when the lower limit of the inclination angle of the electric furnace body is reached;

[0038] P5 max : the coordinate value of reaching the position above the molten pool when the upper limit of the inclination angle of the electric furnace body is reached;

[0039] T: the actual inclination ratio.

[0040] According to the measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot, the method is characterized in that:

[0041] First, according to the actual inclination limit of the current electric furnace body, the coordinate information of the robot gun into the furnace temperature sampling trajectory is taught at the upper and lower limit positions of the electric furnace body inclination,

[0042] Then, within the inclination limit of the electric furnace body, the robot gun into the furnace temperature sampling trajectory is determined according to the teaching and the actual inclination of the electric furnace.

[0043] According to the electric furnace molten steel temperature sampling robot measuring point position control method of the application, the method comprises the following steps:

[0044] In the subroutine, there are comparison operation threads of real-time temperature value and set detection threshold, and comparison operation threads of heating rate and set heating rate threshold;

[0045] When the real-time temperature value is greater than the set detection threshold and the heating rate is greater than the set heating rate threshold, it is determined that the gun reaches the molten pool liquid level.

[0046] According to the electric furnace molten steel temperature sampling robot measuring point position control method of the application, the method comprises the following steps:

[0047] In the subroutine, there are comparison operation threads of real-time temperature value and set detection threshold, and comparison operation threads of heating rate and set heating rate threshold;

[0048] According to the electric furnace molten steel temperature sampling robot measuring point position control method of the application, the method comprises the following steps:

[0049] The actual inclination ratio T is determined according to the following formula:

[0050] T = [(A-A min ) / (A max -A min )] × 100%,

[0051] In the above formula,

[0052] T: actual inclination ratio;

[0053] A: actual furnace body inclination;

[0054] A min : lower limit of the inclination of the current furnace body;

[0055] A max : upper limit of the inclination of the current furnace body.

[0056] According to the electric furnace molten steel temperature sampling robot measuring point position control method of the application, the method comprises the following steps:

[0057] When the depth of the target measuring point is less than or equal to the depth of the deepest measuring point, the temperature measurement is performed on the target measuring point;

[0058] When the depth of the target measuring point is greater than the depth of the deepest measuring point, the temperature measurement is completed on the deepest measuring point as the target measuring point.

[0059] The measuring point position control method of the electric furnace molten steel temperature measurement and sampling robot according to the present application is characterized in that:

[0060] The temperature measuring instrument is a thermocouple type temperature measuring instrument.

[0061] The measuring point position control method of the electric furnace molten steel temperature measurement and sampling robot according to the present application makes the electric furnace temperature measurement and sampling robot carrying the measuring gun into the furnace measurement operation more intelligent, can adaptively adjust the measuring point position according to the furnace body angle, the molten steel surface height and other dynamic furnace conditions of the electric furnace, thereby improving the accuracy and reliability of the robot measuring gun inserted into the molten steel surface measurement; has the characteristics of simple deployment, low cost, high reliability and convenient maintenance, improves the safety, reliability and intelligent degree of the electric furnace robot temperature measurement and sampling operation, and creates favorable conditions for reducing the labor load in harsh environment and improving the labor productivity of the steel plant. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 The figure is a measuring point position control method flowchart in the embodiment of the present application;

[0063] Figure 2 The figure is a furnace entry trajectory coordinate determination flowchart in the embodiment of the present application;

[0064] Figure 3 The figure is a detection flowchart of whether the molten pool surface is reached in the embodiment of the present application;

[0065] Figure 4 The figure is a measuring gun furnace entry key point diagram when the furnace body inclination angle = -3° in the embodiment of the present application;

[0066] Figure 5 The figure is a measuring gun furnace entry key point diagram when the furnace body inclination angle = +3° in the embodiment of the present application;

[0067] Figure 6 The figure is a measuring gun furnace entry key point diagram when the furnace body inclination angle = 0° in the embodiment of the present application;

[0068] Figure 7 The figure is a temperature detection change curve diagram in the embodiment of the present application;

[0069] Figure 8 The figure is a measuring point position control system structure diagram in the embodiment of the present application.

[0070] In the figure,

[0071] P0 - standby position;

[0072] P1 - directly opposite the furnace mouth position;

[0073] P3 - near the furnace mouth position;

[0074] P4 - into the furnace position;

[0075] P5 - above the molten pool position;

[0076] P6 - lowest measuring point position;

[0077] P bath - position at which the measuring gun reaches the molten pool surface;

[0078] P trg - target measuring point position;

[0079] 1 - robot body;

[0080] 2 - robot control unit;

[0081] 3 - measuring gun;

[0082] 4 - temperature measuring instrument;

[0083] 5 - temperature sensing probe;

[0084] 6 - inclination sensor;

[0085] 7 - furnace body;

[0086] 8 - electrode. DETAILED DESCRIPTION

[0087] Hereinafter, a measuring point position control method for an electric furnace molten steel temperature measuring and sampling robot according to the present application will be further described in detail with reference to the accompanying drawings and specific embodiments.

[0088] A measuring point position control method for an electric furnace molten steel temperature measuring and sampling robot,

[0089] Within the inclination limit range of the electric furnace body, the furnace entry temperature measuring and sampling trajectory of the robot measuring gun is determined according to the actual inclination of the electric furnace, and the robot measuring gun is fed to the target measuring point and the temperature of the target measuring point is measured by the measuring gun according to the trajectory and in combination with the position information at which the measuring gun reaches the molten pool surface.

[0090] wherein,

[0091] The furnace entry temperature measuring trajectory of the robot measuring gun is established by determining the positions of the following key points:

[0092] the furnace mouth position, the furnace entry position, and the above molten pool position.

[0093] wherein,

[0094] The temperature sensing probe is arranged at the end of the robot measuring gun, and a temperature measuring instrument is established according to the temperature sensing probe. Through the subprogram arranged in cooperation with the temperature measuring instrument, the determination of whether the measuring gun reaches the liquid surface of the molten pool is established by calling the subprogram through the running of the main program.

[0095] The key points include the following:

[0096] The position information of the measuring gun when reaching the liquid surface of the molten pool and the feeding of the robot measuring gun to the target measuring point are as follows:

[0097] When the measuring gun reaches the liquid surface of the molten pool, the three-dimensional position coordinates of the robot measuring gun at this moment are recorded, and the Z-direction information of the three-dimensional position coordinates is summed with the target depth to form the Z-direction information of the target measuring point. The X and Y information in the three-dimensional position coordinate information of the robot measuring gun when reaching the liquid surface of the molten pool is combined to establish the three-dimensional position information of the target measuring point of the measuring gun, and the feeding of the measuring gun is completed according to the three-dimensional position information.

[0098] The key points include the following:

[0099] The key points further include the following:

[0100] The standby position, the position directly opposite the furnace opening, and the position close to the furnace opening.

[0101] The key points include the following:

[0102] The key points further include the following:

[0103] The key points include the following:

[0104] The position of reaching the furnace opening, the position of entering the furnace, and the position of reaching above the molten pool are determined according to the following:

[0105] P3 = P3 min +(P3 max -P3 min ) × T

[0106] P4 = P4 min +(P4 max -P4 min ) × T

[0107] P5 = P5 min +(P5 max -P5 min ) × T

[0108] In the above formula,

[0109] P3: the coordinate value of actually reaching the furnace opening;

[0110] P4: the coordinate value of actually entering the furnace;

[0111] P5: coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0112] P3 min : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0113] P3 max : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0114] P4 min : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0115] P4 max : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0116] P5 min : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0117] P5 max : coordinate value of the position above the molten pool when the actual inclination angle of the electric furnace body is at the lower limit;

[0118] T: actual inclination ratio.

[0119] wherein,

[0120] First, according to the actual inclination limit of the current electric furnace body, the coordinate information of the robot gun-in-furnace temperature measurement sampling track is taught at the upper and lower limit positions of the electric furnace body inclination angle,

[0121] Then, within the inclination limit range of the electric furnace body, the robot gun-in-furnace temperature measurement sampling track is determined according to the teaching and the actual inclination of the electric furnace.

[0122] wherein,

[0123] In the subroutine, there are comparison operation threads of the real-time temperature value and the set detection threshold, and comparison operation threads of the heating rate and the set heating rate threshold;

[0124] When the real-time temperature value is greater than the set detection threshold and the heating rate is greater than the set heating rate threshold, it is determined that the gun has reached the molten pool surface.

[0125] wherein,

[0126] In the subroutine, there is a determination of whether the real-time temperature value exceeds the set starting threshold, and when the real-time temperature value exceeds the set starting threshold, the real-time calculation of the heating rate is triggered; otherwise, the real-time calculation of the heating rate is not triggered.

[0127] wherein,

[0128] The actual inclination ratio T is determined according to the following formula:

[0129] T = [(A-A min ) / (A max -A min )] x 100%,

[0130] In the above formula,

[0131] T: actual inclination ratio;

[0132] A: actual furnace body inclination angle;

[0133] A min : lower limit of the inclination angle of the current furnace body;

[0134] A max : upper limit of the inclination angle of the current furnace body.

[0135] Wherein,

[0136] When the depth of the target measuring point is less than or equal to the depth of the deepest measuring point, the temperature measurement is performed on the target measuring point;

[0137] When the depth of the target measuring point is greater than the depth of the deepest measuring point, the temperature measurement is completed by taking the deepest measuring point as the target measuring point.

[0138] Wherein,

[0139] The temperature measuring instrument is a thermocouple type temperature measuring instrument.

[0140] Working process, principle and embodiment

[0141] The purpose of the present application is to provide a kind of electric furnace molten steel temperature sampling robot measuring point position control method, to solve the deficiency of prior art in measuring point position and depth control, to guarantee the accuracy and reliability of robot temperature sampling.

[0142] In order to achieve the above purpose, the present application establishes the technical scheme according to the following logic:

[0143] The measuring point position control method, as shown in Figure 1 , includes the following steps:

[0144] 1) When starting temperature sampling, the robot control unit determines the corresponding furnace entry trajectory according to the furnace body inclination angle detected by the inclination sensor, and controls the robot to extend the measuring gun with temperature sensing probe into the furnace;

[0145] 2) When the temperature sensing probe on the measuring gun contacts the steel liquid surface, the thermocouple on the temperature sensing probe senses the temperature change of the steel liquid surface, and the molten pool liquid level detection signal is sent out through the temperature measuring instrument;

[0146] 3) The robot control unit records the three-dimensional coordinates of the robot probe at this moment according to the molten pool liquid level detection signal fed back by the temperature measuring instrument;

[0147] 4) The robot control unit controls the probe to continue to insert into the molten pool along the Z-axis and move downward by a predetermined measuring point depth based on the recorded probe position coordinates at the time when the molten pool liquid level detection signal is received, until the target measuring point is reached;

[0148] 5) After the probe reaches the target measuring point, when the temperature measuring instrument connected to the temperature probe sends a measurement completion signal or exceeds the maximum measurement time, the robot control unit controls the probe to move out of the furnace in the opposite direction of the entry into the furnace and return to the standby position, and the measurement is completed.

[0149] The entry trajectory of step 1 above is determined according to the position of the robot entry teaching point and the furnace body inclination detected by the inclination sensor at that time, including the following steps;

[0150] 1.1) The allowable range of the furnace body inclination for the robot temperature measurement and sampling operation is preset;

[0151] 1.2) The key points on the robot probe entry trajectory for temperature measurement and sampling are taught at the upper and lower limit positions of the furnace body inclination, respectively;

[0152] 1.3) The entry trajectory points are calculated and corrected according to the actual furnace body inclination at the start of measurement to obtain the entry trajectory coordinates matching the current inclination;

[0153] The molten pool liquid level detection signal of step 2 above is transmitted to the robot control unit by the temperature measuring instrument after receiving the thermocouple signal of the temperature probe, and is determined according to the following steps:

[0154] 2.1) When the probe approaches the molten steel pool liquid surface, the change of the probe thermocouple signal causes the temperature measurement value of the temperature measuring instrument to start rising;

[0155] 2.2) When the temperature measurement value on the temperature measuring instrument exceeds the starting threshold, the temperature measuring instrument starts to calculate the temperature rise rate in real time;

[0156] 2.3) When the temperature measurement value of the temperature measuring instrument continues to rise and exceeds the detection threshold, and the temperature rise rate is greater than the predetermined temperature rise rate threshold, the molten pool liquid level detection signal is sent to the robot control unit.

[0157] The coordinate position of the target measuring point of step 4 above is obtained by subtracting the predetermined measuring point depth from the Z coordinate in the three-dimensional coordinates of the probe at the time when the molten pool liquid level detection signal is received;

[0158] The coordinate position of the target measuring point of step 4 has a limit position, which is determined when the robot temperature measuring sampling demonstration is performed, and corresponds to the lowest measuring point position; when the Z-axis coordinate of the robot target measuring point is lower than the Z-axis coordinate of the lowest measuring point position, the coordinate of the lowest measuring point position is used as the coordinate of the target measuring point, which is used for limit protection of the robot gun insertion position;

[0159] For supporting the above-mentioned method, including a robot body, a robot control unit, a measuring gun, a temperature sensing probe, a temperature measuring instrument, an inclination sensor, such as Figure 8 ;

[0160] The robot body is composed of a six-axis robot;

[0161] The robot control unit includes a robot controller connected to the robot body, which is used to control and demonstrate the motion trajectory of the robot;

[0162] The measuring gun is a gun body tool connected to the sixth axis flange of the robot for carrying the probe into the furnace for temperature sampling;

[0163] The temperature sensing probe includes a sleeve with a thermocouple wire and a contact in the head, and the temperature sensing probe is connected to the measuring gun through the sleeve;

[0164] The temperature measuring instrument is connected to the temperature sensing probe on the measuring gun through a compensation lead, which is used for temperature detection, analysis and display, and can output measurement state and molten pool liquid level detection signals;

[0165] The temperature measuring instrument has three measurement state signals: ready, measuring and completed, and one molten pool liquid level detection signal output;

[0166] The inclination sensor is installed on the outer shell of the electric furnace body, which is used to detect the inclination angle of the electric furnace body, and the detection signal is transmitted to the robot control unit through a signal cable, which is used for trajectory correction of the robot to the measuring point position.

[0167] Embodiment

[0168] This embodiment applies the present application to the robot automatic temperature measuring sampling system of a 150t alternating current electric arc furnace. The embodiments of the present application will be further described below with reference to the accompanying drawings.

[0169] The measuring point position control method shown in Figure 1 includes the following steps:

[0170] 1) When starting temperature sampling, the robot control unit determines the corresponding furnace trajectory according to the inclination angle of the furnace body detected by the inclination sensor, and controls the robot to extend the measuring gun with the temperature sensing probe into the furnace;

[0171] The furnace entry trajectory is determined according to the position of the robot furnace entry teaching point and the furnace body inclination angle detected by the inclination angle sensor at that time, as shown in Figure 2 The method comprises the following steps, as shown in

[0172] 1.1) preset the allowable furnace body inclination angle range of the robot temperature measurement sampling operation;

[0173] In this example, the allowable furnace body inclination angle range of the robot during temperature measurement sampling operation is -3.0~+3.0°. Within this inclination angle range, the robot can start temperature measurement sampling, and outside this inclination angle range, the robot is not allowed to measure temperature sampling, so as to ensure that no collision occurs during furnace entry and the required measurement point position is achieved;

[0174] 1.2) respectively at the upper and lower limit positions of the furnace body inclination angle, teach the key point positions on the robot gun furnace entry temperature measurement sampling trajectory;

[0175] As shown in Figure 4 and Figure 5 In this example, the key point positions on the robot furnace entry temperature measurement sampling trajectory are respectively taught when the furnace body inclination angle =-3.0° and the furnace body inclination angle =+3.0°, and the coordinate positions of the key point positions at ±3° are determined;

[0176] As shown in Figure 4 and Figure 5 The key point positions on the robot furnace entry temperature measurement sampling trajectory in this example include: P0-waiting position, P1-directly opposite the furnace opening position, P2-close to the furnace opening position, P3-reach the furnace opening position, P4-enter the furnace position, P5-reach the position above the molten pool, P6-reach the lowest measurement point position; Wherein P0, P1, P2 are independent of the inclination angle and do not change with the change of the inclination angle, P3, P4, P5, P6 are related to the inclination angle, and need to be respectively taught when the furnace body inclination angle =-3.0° and the furnace body inclination angle =+3.0°, so as to determine different coordinate limit positions at the two extreme inclination angles;

[0177] In this example, the coordinate values of the key point positions on the robot furnace entry temperature measurement sampling trajectory are respectively:

[0178] P0=[-409.88,-4697.93,898.22],

[0179] P1=[2827.39,1181.53,1159.83],

[0180] P2=[2656.06,2154.97,1175.94];

[0181] In this example, the coordinate value P3 +30 of the robot furnace entry temperature measurement sampling trajectory at inclination angle =+3.0° is [2543.28, 2891.38, 1511.72], P4+30 = [2543.22, 4175.61, 1481.46], P5 +30 = [2522.40, 5469.91, 1343.63], P6 +30 = [2730.99, 5768.73, 220.73];

[0182] In this example, the coordinate value of P3 at the inclination angle of -3.0° is -30 = [2514.77, 3149.33, 1194.99], P4 -30 = [2483.40, 4193.40, 1140.95], P5 -30 = [2316.34, 5471.25, 898.71], P6 -30 = [2703.2, 5724.97, -17.12]

[0183] 1.3) According to the actual furnace body inclination angle at the time of starting measurement, the calculation correction is made on the furnace entry trajectory point to obtain the furnace entry trajectory coordinates matched with the current inclination angle;

[0184] In this example, the coordinate values of the key points P3, P4, P5, P6 on the furnace entry trajectory are calculated and corrected according to the following formula:

[0185] P3 = P3 -30 + (P3 +30 - P3 -30 ) * T

[0186] P4 = P4 -30 + (P4 +30 - P4 -30 ) * T

[0187] P5 = P5 -30 + (P5 +30 - P5 -30 ) * T

[0188] P6 = P6 -30 + (P6 +30 - P6 -30 ) * T

[0189] Wherein T is the inclination ratio, measured based on the inclination angle lower limit, expressed in percentage: T = (A - A min ) / (A max - A min ) * 100%;

[0190] In this example, A max = +3.0, A min= -3.0, the actual furnace body inclination is denoted by A; the actual furnace body at the time of starting measurement is in a horizontal position, when the inclination A = 0°, the inclination T = 50%, as shown in Figure 6 The coordinate value calculation results of the key point positions P3, P4, P5, P6 on the furnace entry trajectory are as follows:

[0191] P3 = [2529.025, 3020.355, 1353.355]

[0192] P4 = [2513.31, 4184.505, 1311.205]

[0193] P5 = [2419.37, 5470.58, 1121.17]

[0194] P6 = [2717.095, 5746.85, 101.805]

[0195] 2) When the temperature sensing probe on the measuring gun contacts the steel liquid surface, the temperature sensing probe hot wire senses the change of the steel liquid surface temperature, and the temperature measuring instrument sends a molten pool liquid surface detection signal;

[0196] The molten pool liquid surface detection signal is transmitted to the robot control unit after the temperature measuring instrument receives the temperature sensing probe hot wire signal, as shown in Figure 3 The following steps are used to determine:

[0197] 2.1) When the measuring gun carrying the temperature sensing probe approaches the steel water molten pool liquid surface, the change of the probe hot wire signal makes the temperature measurement value of the temperature measuring instrument start to rise;

[0198] The temperature change of the present example when entering the furnace is shown in the a-b section of the Figure 7 curve;

[0199] 2.2) When the temperature measurement value on the temperature measuring instrument exceeds the starting threshold value, the temperature measuring instrument starts to calculate the temperature rise rate in real time;

[0200] The b-c section of the Figure 7 curve of the present example is shown, the starting threshold value = 100°C;

[0201] 2.3) When the temperature measurement value of the temperature measuring instrument continues to rise and exceeds the detection threshold value, and the temperature rise rate is greater than the predetermined temperature rise rate threshold value, the molten pool liquid surface detection signal is sent to the robot control unit.

[0202] The c-d section of the Figure 7 curve of the present example is shown, the detection threshold value = 300°C, and the temperature rise rate threshold value = 1000°C / s;

[0203] 3) The robot control unit records the three-dimensional position coordinates of the robot's measuring gun at this moment based on the molten pool level detection signal fed back by the temperature measuring instrument;

[0204] In this example, as Figure 6 As shown, after receiving the molten pool level detection signal, the robot control unit saves the three-dimensional position coordinates of the robot's measuring gun at that time in P. bath In the middle, P bath =[x,y,z]=[2760.26,5746.13,460.07];

[0205] 4) The robot control unit uses the probe position coordinates recorded when it receives the molten pool surface detection signal as a reference to control the probe to continue to insert into the molten pool and move down the predetermined measuring point depth along the Z-axis until the target measuring point is reached.

[0206] The coordinate position of the target measuring point is obtained by subtracting the predetermined measuring point depth from the Z coordinate of the measuring gun in the three-dimensional coordinates of the measuring gun when the molten pool surface detection signal is received.

[0207] In this example, as Figure 6 As shown, the predetermined measuring point depth offset = 300mm, the Z coordinate in the three-dimensional coordinate system of the measuring gun when the molten pool surface detection signal is received is 460.07, and the target measuring point P... trg The coordinates are [x, y, z - 300] = [2760.26, 5746.13, 160.07];

[0208] The target measuring point has a limit position, which is determined during robot temperature sampling teaching and corresponds to the lowest measuring point position. When the Z-axis coordinate of the robot's target measuring point is lower than the Z-axis coordinate of the lowest measuring point position, the coordinate of the lowest measuring point position is used as the target measuring point coordinate for limit protection of the robot's measuring gun insertion position.

[0209] In this example, the coordinates of the lowest measuring point P are... min =P6=[2717.095,5746.85,101.805], as shown Figure 6 As shown;

[0210] 5) After the measuring gun reaches the target measuring point, when the temperature measuring instrument connected to the temperature sensing probe sends a measurement completion signal, or when the maximum measurement time has been exceeded, the robot control unit controls the measuring gun to exit the furnace in the opposite direction of entering the furnace and return to the standby position, and the measurement ends.

[0211] In this example, the maximum measurement time is set to 6 seconds. After the measuring gun reaches the target measurement point, the temperature measuring instrument sends a measurement completion signal, and the robot control unit controls the measuring gun, such as... Figure 6 As shown, follow the path from point P5 to point P4 to point P3 to point P2 to point P1, and return to the standby position P0.

[0212] The system structure for supporting the method for completing control is shown in Figure 8 The system structure for supporting the method for completing control is shown in

[0213] The present example is applied to a 150t AC electric arc furnace, which has a furnace body 7 and an electrode 8;

[0214] The robot body 1 is composed of a six-axis robot;

[0215] The present example adopts a standard six-axis robot, which has six joint axes and a maximum arm length of 3m;

[0216] The robot control unit 2 includes a robot controller connected with the robot body, which is used for controlling and teaching the motion trajectory of the robot;

[0217] The robot control unit of the present example adopts a controller matched with the robot body, which has a processing control board, a driving board, an IO interface board, a communication board and a teach box;

[0218] The measuring gun 3 is a gun body tool connected with the sixth axis flange of the robot, which is used for carrying the probe into the furnace for temperature sampling;

[0219] The measuring gun of the present example is installed on the sixth axis flange of the robot, which is mainly made of seamless steel pipe, has a connector pipe at the front end for connecting with the temperature probe, and has a compensation wire inside for transmitting the measurement signal of the temperature probe to the temperature measuring instrument;

[0220] The temperature probe 5 includes a sleeve with a thermocouple wire and a contact point at the head, and the temperature probe is connected with the measuring gun through the sleeve;

[0221] The temperature probe of the present example adopts a composite temperature measuring and oxygen determining probe, and the thermocouple wire adopts R type graduation number with a measurement range of 400-1760℃;

[0222] The temperature measuring instrument 4 is connected with the temperature probe on the measuring gun through the compensation wire, which is used for temperature detection, analysis and display, and can output the measurement state and the molten pool liquid level detection signal;

[0223] The temperature measuring instrument has three measurement state signals of ready, measuring and measurement completed, and one molten pool liquid level detection signal output;

[0224] The temperature measuring instrument of the present example adopts a double-channel temperature measuring instrument, which has multiple measurement and analysis functions such as temperature measurement, oxygen determination and carbon determination; the temperature measuring instrument of the present example has three on-off signal dry contact point outputs of ready, measuring and measurement completed, and one molten pool liquid level detection on-off signal dry contact point output;

[0225] The inclination sensor 6 is installed on the outer shell of the electric furnace body and is used to detect the inclination angle of the electric furnace body. The detection signal is transmitted to the robot control unit through a signal cable for trajectory correction of the robot to the measurement point position.

[0226] The inclination sensor signal interface of the present example is 4-20 mA, and the measurement angle range is -90~+90°, and 0° when the furnace body is in a horizontal state.

Claims

1. A measuring point position control method of an electric furnace molten steel temperature sampling robot, characterized in that: within the inclination limit range of the electric furnace body, the in-furnace temperature sampling trajectory of the robot measuring lance is determined according to the actual inclination of the electric furnace, and the advancement of the robot measuring lance to the target measuring point and the temperature measurement of the target measuring point are completed according to the trajectory and the position information when the measuring lance reaches the molten pool liquid surface; specifically, the coordinate information of the in-furnace temperature sampling trajectory of the robot measuring lance is taught at the upper and lower limit positions of the inclination of the electric furnace body according to the actual inclination limit of the current electric furnace body; then, within the inclination limit range of the electric furnace body, the in-furnace temperature sampling trajectory of the robot measuring lance is determined according to the teaching and the actual inclination of the electric furnace; a temperature sensing probe is arranged at the end of the robot measuring lance, and a temperature measuring instrument is established accordingly; through the subprogram set by the temperature measuring instrument, the determination of whether the measuring lance reaches the molten pool liquid surface is established by running the main program to call the subprogram; in the subprogram, there are comparison operation threads of the real-time temperature value and the set detection threshold value, and comparison operation threads of the temperature rise rate and the set temperature rise rate threshold value; when the real-time temperature value is greater than the set detection threshold value and the temperature rise rate is greater than the set temperature rise rate threshold value, it is determined that the measuring lance reaches the molten pool liquid surface; in the subprogram, there is a determination of whether the real-time temperature value exceeds the set starting threshold value; when the real-time temperature value exceeds the set starting threshold value, the real-time calculation of the temperature rise rate is triggered; otherwise, the real-time calculation of the temperature rise rate is not triggered. 2.The measuring point position control method of an electric furnace molten steel temperature sampling robot according to claim 1, characterized in that: the in-furnace temperature sampling trajectory of the robot measuring lance is established by determining the positions of the following key points: the reaching furnace mouth position, the entering furnace position, and the reaching molten pool upper position. 3.The measuring point position control method of an electric furnace molten steel temperature sampling robot according to claim 1, characterized in that: the advancement of the robot measuring lance to the target measuring point in combination with the position information when the measuring lance reaches the molten pool liquid surface is specifically: when the measuring lance reaches the molten pool liquid surface, the three-dimensional position coordinates of the robot measuring lance at that moment are recorded, and the Z-direction information of the three-dimensional position coordinates is summed with the target depth to form the Z-direction information of the target measuring point; the X and Y information in the three-dimensional position coordinate information when the robot measuring lance reaches the molten pool liquid surface is combined to complete the establishment of the three-dimensional position information of the target measuring point of the measuring lance, and the advancement of the measuring lance is completed according to the three-dimensional position information. 4.The measuring point position control method of an electric furnace molten steel temperature sampling robot according to claim 2, characterized in that: the key points further include the following: the standby position, the directly opposite furnace mouth position, and the near furnace mouth position. 5.The measuring point position control method of an electric furnace molten steel temperature sampling robot according to claim 2, characterized in that: the key points further include the reaching deepest measuring point position. 6.The measuring point position control method of an electric furnace molten steel temperature sampling robot according to claim 2, characterized in that: the positions of the reaching furnace mouth position, the entering furnace position, and the reaching molten pool upper position are specifically determined as follows: in the above formula, P1: the coordinate value of the reaching furnace mouth position; P2: the coordinate value of the entering furnace position; P3: the coordinate value of the reaching molten pool upper position. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ P3 = P3 min + (P3 max - P3 min ) x T P4 = P4 min + (P4 max - P4 min ) x T P5 = P5 min + (P5 max - P5 min ) x T ​ ​ P4: actual coordinate value of entering into the furnace; P5: actual coordinate value of reaching above the molten pool P3 min : coordinate value of reaching the mouth of the furnace when the inclination of the furnace body is lower limit P3 max : coordinate value of reaching the mouth of the furnace when the inclination of the furnace body is upper limited; P4 min : coordinate value of the entering position in the furnace when the inclination of the furnace body is at the lower limit P4 max : coordinate value of the entering position in the furnace when the inclination of the furnace body is upper limited P5 min : coordinate value of reaching the position above the molten pool when the inclination of the electric furnace body is lower limit P5 max : coordinate value of reaching above the molten pool when the upper limit of the inclination angle of the electric furnace body T: actual inclination ratio.

7. The measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot according to claim 6, characterized in that: the actual inclination ratio T is determined according to the following formula: T = [(A - A min ) / (A max - A min )] x 100%, in the above formula, T: actual inclination ratio; A: actual furnace body inclination angle; A min : lower limit of the inclination angle of the current furnace body; A max : upper limit of the inclination angle of the current furnace body.

8. The measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot according to claim 5, characterized in that: when the depth of the target measuring point is less than or equal to the depth of the deepest measuring point, the temperature measurement is performed on the target measuring point; when the depth of the target measuring point is greater than the depth of the deepest measuring point, the temperature measurement is completed by taking the deepest measuring point as the target measuring point.

9. The measuring point position control method of the electric furnace molten steel temperature measuring and sampling robot according to claim 1, characterized in that: the temperature measuring instrument is a thermocouple type temperature measuring instrument.

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