A method for realizing a linear motor for an automatic sliding door

Abstract

A method for realizing a linear motor for automatic sliding doors, in the technical field of linear motors; the entire motor has two groups of stators, a circuit board is located between the two groups of stators, an analog Hall device for detecting motor magnets is located on the circuit board, the stator and the circuit board are wrapped by an outer sheath and an upper cover, the mover of the motor contains a long aluminum bar, and a row of staggered and evenly arranged magnets are located at the bottom, the motor stator is inserted into the middle of a profile groove, two machine screws on the left and right ends of the stator are tightened, the mover is inserted into a slide groove of a profile, and block assemblies are locked at the two ends of the profile, after power is turned on, the motor stator will generate a three-phase alternating moving magnetic field, so that the mover moves linearly between two blocks in the slide groove, and a method for realizing a linear motor for automatic sliding doors with a reasonable structure is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of linear motors, and in particular relates to a method for realizing an automatic sliding door linear motor with excellent performance. Background Art

[0002] The linear motor distance detection used in early automatic sliding doors adopted Schmidt switch Hall devices. The detected motor movement distance was discrete jumps. For a conventional 12mm wide magnetic steel, the resolution of three evenly distributed Hall devices was 4mm. In order to further improve the motion control accuracy, the present invention adopts analog Hall devices to obtain the current one-dimensional coordinate point of the mover by simulating the continuous change of the strength of the magnetic steel detected by the Hall devices.

[0003] The linear motors used in the early automatic sliding doors were all driven by PWM, which had the disadvantages of large torque fluctuations and electromagnetic noise. The motor positioning torque adjustment granularity was large. The recent motors are driven by SVPWM, which has the disadvantages of complex vector calculations, heavy current decoupling tasks, and slightly higher device costs. Summary of the invention

[0004] The purpose of the present invention is to provide a method for realizing a linear motor for an automatic sliding door with a reasonable structure.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] A method for realizing a linear motor for an automatic sliding door, comprising a profile, a mover, a mover magnetic steel 103, a left stator coil, a right stator coil, a motor mainboard, an outer sleeve of a stator, an upper cover, a block assembly 201, a slide groove for mounting a motor mover, a groove for mounting a motor stator, a pulley of the mover, a rectangular grid for mounting a junction box circuit board, a rectangular grid for mounting a left stator coil, a rectangular grid for mounting a mainboard, a rectangular grid for mounting a right stator coil, a rectangular grid for mounting a power supply circuit board, a motor fixing hole, a left analog Hall device on the mainboard, a right analog Hall device on the mainboard, and the entire motor has two sets of stators. There is a circuit board in the middle of the two groups of stators. There is an analog Hall device on the circuit board for detecting the motor magnet. The stator and the circuit board are wrapped by an outer sleeve and an upper cover. The motor's mover contains a long aluminum bar and a row of staggered and evenly arranged magnets at the bottom. Insert the motor stator into the middle of the profile groove, and then tighten the two machine screws on the left and right ends of the stator. Then insert the mover into the slide groove of the profile, and lock the block assembly at the two ends of the profile. After power is turned on, the motor stator will generate a three-phase alternating moving magnetic field, causing the mover to move in a straight line between the two blocks in the slide groove.

[0007] The implementation method of a linear motor for an automatic sliding door is to obtain the running position of the magnetic steel aligned by the Hall device on the mover through the strength values ​​of the signals simultaneously output by two adjacent Hall devices, and to obtain the two-dimensional data and to look up the table to know the fine-grained position value of the magnetic steel. Then, by superimposing all the movement intervals of the magnetic steel detected by the Hall device, the current one-dimensional coordinate value of the motor mover can be obtained. Secondly, based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a certain Hall device has poor continuity or distortion due to external interference, it can be compared and repaired through the continuous data of the adjacent Hall device. Furthermore, when there is a problem with a certain magnetic steel, the dual Hall devices can detect the strength data of the adjacent magnetic steel and repair the data. When interference with the data of a Hall device occurs, it can be repaired through the data of the adjacent Hall device. The extraction of multiple data improves the reliability of detection.

[0008] The realization method of the linear motor for automatic sliding door, the realization process of SPWM sine wave

[0009] 1. The two-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by two adjacent Hall devices is mapped to the AC SPWM table of the motor after offset correction through the table lookup method;

[0010] 2. The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by a Hall device is mapped to the auxiliary AC SPWM table 1 of the motor after offset correction through the table lookup method;

[0011] 3. The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by the adjacent Hall device is mapped to the auxiliary AC SPWM table 2 of the motor after offset correction through the table lookup method;

[0012] Based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a Hall device is discontinuous or distorted, it can be repaired by comparing and repairing it with the continuous data of the adjacent Hall device. In addition, when a piece of magnetic steel has a slight defect, the dual Hall device can detect the strength data of the adjacent magnetic steel and repair the data. When the data of a Hall device is disturbed, it can be repaired by the data of the adjacent Hall device.

[0013] The SPWM waveform data obtained by the table lookup is passed through a three-phase PWM generator to complete three-phase signal fission and then passes through a three-phase power MOSFET bridge to drive the three-phase linear motor to move.

[0014] Automatic sliding door linear motor action process

[0015] 1. After power-on, the motor runs toward the door opening end and reaches the top of the door opening end. Set this point as the starting origin for the next step of learning.

[0016] 2. The motor starts to run towards the door closing end. When it reaches the top of the door closing end, the length of the motor's running range in the door opening direction can be obtained. At the same time, the maximum value data of the magnetic flux of all magnetic steels are collected.

[0017] 3. The motor runs toward the door opening end again. When it reaches the top of the door opening end, the length of the motor's running range in the door closing direction can be obtained. At the same time, the maximum value data of the magnetic flux of all magnetic steels are collected.

[0018] 4. Compare the interval length and flux data in both directions to further correct the error. Ensure successful learning

[0019] 5. The motor closes the door. When it reaches the top of the closing end, the learning is completed.

[0020] 6. Enter the ready state and wait for the running action instruction.

[0021] 7. Complete the running action, enter the ready state, wait for the running action instruction, and repeat this cycle.

[0022] The beneficial effects of the present invention are:

[0023] 1. The operation is simple, and a simple SPWM table lookup method can be used. The requirements for the operation chip are low. The three tables are checked against each other, which improves the reliability and can repair some minor defects of the magnetic steel or Hall.

[0024] 2. Only one operational amplifier is needed for one motor stator, which can monitor the three-phase winding current of the motor at the same time, and any channel or bridge circuit can be protected in time if it is overcurrent or short-circuited.

[0025] 3. Because it is a voltage-type SPWM, there is no high-speed detection requirement for current detection, which improves anti-interference performance.

[0026] 4. Because there is no need for AC and DC axis current operational decoupling, there is no need for multiple high-bandwidth precision current op amps. Only an ordinary single op amp is needed for motor current detection, which is low in cost. Because the current control loop has a low bandwidth, it has stronger anti-interference ability and strong stability.

[0027] 5. The output torque is smooth, the positioning torque adjustment granularity is small, the current harmonic component is small, and the measured heat generation of the motor and MOSFET is very low. At present, a 300W motor drives a 500kg door body, and the power drive bridge only uses 6 TO-252 SMD packaged MOSFETs, which reduces material costs and assembly costs, and greatly improves the reliability of the processing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0029] Figure 1Schematic diagram of the process structure of the present invention

[0030] 101-profile; 102-motor; 103-motor magnet; 104-left stator coil; 105-right stator coil; 106-motor mainboard; 107-stator outer sleeve; 108-upper cover;

[0031] 201-block assembly; 202-slideway for motor mover; 203-slot for motor stator; 204-pulley for mover; 205-rectangular grid for junction box circuit board; 206-rectangular grid for left stator coil; 207-rectangular grid for main board; 208-rectangular grid for right stator coil; 209-rectangular grid for power supply circuit board; 210-motor fixing hole; 211-left analog Hall device on main board; 212-right analog Hall device on main board; DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific examples.

[0033] A method for realizing a linear motor for an automatic sliding door, comprising a profile 101, a mover 102, a mover magnetic steel 103, a left stator coil 104, a right stator coil 105, a motor mainboard 106, an outer sleeve 107 of the stator, an upper cover 108, a block assembly 201, a slide groove 202 for mounting the motor mover, a groove 203 for mounting the motor stator, a pulley 204 of the mover, a rectangular grid 205 for mounting a junction box circuit board, a rectangular grid 206 for mounting the left stator coil, a rectangular grid 207 for mounting the mainboard, a rectangular grid 208 for mounting the right stator coil, a rectangular grid 209 for mounting a power supply circuit board, a motor fixing hole 210, and an analog Hall device 210 on the left side of the mainboard. 1. The analog Hall device 212 on the right side of the main board. The whole motor has two sets of stators. There is a circuit main board in the middle of the two sets of stators. There are analog Hall devices for detecting the motor magnets on the circuit main board. The stator and the circuit board are wrapped by the outer sleeve and the upper cover. The mover of the motor contains a long aluminum bar and a row of staggered and evenly arranged magnets at the bottom. Insert the motor stator into the middle of the groove of the profile, and then tighten the two machine screws on the left and right ends of the stator. Then insert the mover into the slide groove of the profile, and lock the block assembly at the two ends of the profile. After power is turned on, the motor stator will generate a three-phase alternating moving magnetic field, causing the mover to move linearly between the two blocks in the slide groove.

[0034] A method for implementing a linear motor for an automatic sliding door, using the intensity values ​​of the signals simultaneously output by two adjacent Hall devices to obtain the running position of the magnetic steel aligned by the Hall device on the mover, and after obtaining the two-dimensional data, a table lookup is performed to know the fine-grained position value of the magnetic steel, and then, by superimposing all the movement intervals of the magnetic steel detected by the Hall device, the current one-dimensional coordinate value of the motor mover can be obtained. Secondly, based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a certain Hall device has poor continuity or distortion due to external interference, it can be compared and repaired through the continuous data of the adjacent Hall device. Furthermore, when a piece of magnetic steel has a problem, the dual Hall device can detect the adjacent magnetic steel intensity data and perform data repair, and when interference with the data of a Hall device comes, it can be repaired through the data of the adjacent Hall device, and the extraction of multiple data improves the reliability of detection.

[0035] A method for realizing a linear motor for an automatic sliding door. Since the external stray magnetic field interference of an analog Hall device is relatively large, the linear motor can first be filtered by software and hardware, and then the correlation analysis of the signal waveforms of the two Hall devices can be performed to further enhance the accuracy of the operation data. The statistical characteristic analysis of the magnetic strength data of all magnetic steels can be performed to compensate for some defects of certain magnetic steels. Since the analog Hall device is cheap and has limited accuracy, it is not a true linear device. Therefore, it is necessary to undergo nonlinear compensation, signal effective range expansion, signal dynamic drift prevention, signal waveform cross-correlation analysis of dual Hall devices and other algorithmic measures to meet the precise calculation of the moving distance of the motor. Generally, after compensation, the motion resolution granularity of the linear motor can reach within 1 mm, which is fully capable of meeting the requirements in the field of automatic sliding doors. For a conventional 12 mm wide magnetic steel, there are not many constraints on the arrangement spacing of the dual Hall devices, ranging from 4 mm to 8 mm, and preferably 6 mm.

[0036] The implementation process of SPWM sine wave

[0037] 1. The two-dimensional data of the magnetic flux signal waveform of the magnetic steel detected simultaneously by two adjacent Hall devices is mapped to the AC SPWM table of the motor after offset correction through table lookup method.

[0038] 2. The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by a Hall device is mapped to the auxiliary AC SPWM table 1 of the motor after offset correction through table lookup method.

[0039] 3. The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by the adjacent Hall device is mapped to the auxiliary AC SPWM table 2 of the motor after offset correction through the table lookup method.

[0040] Based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a Hall device is discontinuous or distorted, it can be repaired by comparing and repairing it with the continuous data of the adjacent Hall device. In addition, when a piece of magnetic steel has a slight defect, the dual Hall device can detect the strength data of the adjacent magnetic steel and repair the data. When the data of a Hall device is disturbed, it can be repaired by the data of the adjacent Hall device.

[0041] The SPWM waveform data obtained by the table lookup is passed through a three-phase PWM generator to complete three-phase signal fission and then passes through a three-phase power MOSFET bridge to drive the three-phase linear motor to move.

[0042] Automatic sliding door linear motor action process

[0043] 1. After power-on, the motor runs toward the door opening end and reaches the top of the door opening end. Set this point as the starting origin for the next step of learning.

[0044] 2. The motor starts to run towards the door closing end. When it reaches the top of the door closing end, the length of the motor's operating range in the door opening direction can be obtained, and the maximum magnetic flux data of all magnetic steels can be collected at the same time.

[0045] 3. The motor runs toward the door opening end again. When it reaches the top of the door opening end, the length of the motor's operating range in the door closing direction can be obtained, and the maximum magnetic flux data of all magnets can be collected at the same time.

[0046] 4. Compare the interval length and flux data in both directions to further correct the error. Ensure successful learning

[0047] 5. The motor closes the door. When it reaches the top of the closing end, the learning is completed.

[0048] 6. Enter the ready state and wait for the running action instruction.

[0049] 7. Complete the running action, enter the ready state, wait for the running action instruction, and repeat this cycle.

[0050] Since no complex vector operations and various trigonometric function operations are used, the computing power requirements for the MPU are relatively low. Domestic chip GDF10x series MPUs can be used, or motor-specific DSC, GD32F40x series can be used. It can meet the needs of single-chip dual-motor drive, double-door communication, external control command communication, and other complex control functions, and is also conducive to subsequent function upgrades and expansions.

[0051] The SPWM waveform data obtained by the table lookup is passed through a three-phase PWM generator to complete three-phase signal fission and then passes through a three-phase power MOSFET bridge to drive the three-phase linear motor to move.

[0052] Regarding the preparation of the two-dimensional to one-dimensional mapping table, when the lateral distance between the two Hall devices and the longitudinal distance between the Hall device and the motor rotor magnet are determined, the output data of the dual Hall device is determined to have its correlation. The data of the dual Hall device is essentially a one-dimensional data sequence Xn, and a data sequence Yn generated after Xn is offset, and the offset distance is determined by the distance between the two Hall devices. The norm of Xn can be adjusted by the longitudinal distance between the Hall device and the motor rotor magnet, and the sequence Xn and the sequence Yn can be intersected (can be oblique or orthogonal) to map out a one-dimensional data sequence Zn. In this way, the aforementioned dual Hall device data sequence mapping to the distance space sequence table and the dual Hall device data sequence mapping to the SPWM waveform data space sequence table can be generated.

[0053] Taking into account that the linear motor can currently drive a 500 kg door body and is still developing towards a larger driving capacity, if the system stability is not enough, the damage caused will be catastrophic. A key point in the stability of the system is the authenticity and accuracy of the mover coordinate data, otherwise there will be serious accidents such as runaway and hitting the door frame. Therefore, the implementation method of the present invention focuses on improving the robustness of the system operation, which is the highest design principle, followed by economy.

[0054] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for realizing a linear motor for an automatic sliding door, which is characterized by: The whole motor has two sets of stators, and there is a circuit board in the middle of the two sets of stators. There is an analog Hall device for detecting the motor magnet on the circuit board. The stator and the circuit board are wrapped by an outer sleeve and an upper cover. The mover of the motor contains a long aluminum bar and a row of staggered and evenly arranged magnets at the bottom. Insert the motor stator into the middle of the groove of the profile, and then tighten the two machine screws on the left and right ends of the stator. Then insert the mover into the slide groove of the profile, and lock the block assembly at the two ends of the profile. After power is turned on, the motor stator will generate a three-phase alternating moving magnetic field, so that the mover moves linearly between the two blocks in the slide groove; The running position of the magnet aligned by the Hall device on the mover is obtained through the intensity values ​​of the signals simultaneously output by two adjacent Hall devices. After obtaining the two-dimensional data, a table is looked up to know the fine-grained position value of the magnet. Then, by superimposing all the movement intervals of the magnet detected by the Hall device, the current one-dimensional coordinate value of the motor mover is obtained. Secondly, based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a certain Hall device has poor continuity or distortion due to external interference, it is repaired by comparing and repairing the continuous data of the adjacent Hall device. Furthermore, when a certain magnet has a problem, the dual Hall devices detect the adjacent magnet strength data and repair the data. When interference with the data of a Hall device comes, it is repaired by the data of the adjacent Hall device. The extraction of multiple data improves the reliability of detection. The implementation process of SPWM sine wave: The two-dimensional data of the magnetic flux signal waveform of the magnet detected by two adjacent Hall devices is mapped to the AC SPWM table of the motor after offset correction through table lookup method; The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by a Hall device is mapped to the auxiliary AC SPWM table 1 of the motor after offset correction through a table lookup method; The one-dimensional data of the magnetic flux signal waveform of the magnetic steel detected by the adjacent Hall device is mapped to the auxiliary AC SPWM table 2 of the motor after offset correction through the table lookup method; Based on the continuity and correlation of the data of two adjacent Hall devices, when the data of a Hall device is discontinuous or distorted, it is repaired by comparing and repairing it with the continuous data of the adjacent Hall device. Furthermore, when a piece of magnetic steel has a slight defect, the dual Hall devices detect the adjacent magnetic steel strength data and repair the data. When the data of a Hall device is disturbed, it is repaired by the data of the adjacent Hall device. The SPWM waveform data obtained by the table lookup is passed through a three-phase PWM generator to complete three-phase signal fission and then passes through a three-phase power MOSFET bridge to drive the three-phase linear motor to move.

2. The method for realizing a linear motor for an automatic sliding door according to claim 1, wherein: Automatic sliding door linear motor action process: After power-on, the motor runs toward the door opening end and reaches the top of the door opening end. This point is set as the starting point for the next step of learning. The motor starts to run towards the door closing end. When it reaches the top of the door closing end, the length of the motor's running range in the door opening direction is obtained, and the maximum value data of the magnetic flux of all magnetic steels are collected at the same time. The motor runs toward the door opening end again. When it reaches the top of the door opening end, the length of the motor's running range in the door closing direction is obtained, and the maximum magnetic flux data of all magnetic steels are collected at the same time. The interval lengths and flux data in both directions are compared to further correct errors and ensure successful learning; The motor closes the door, and when it reaches the top of the closing end, the learning is completed; Enter the ready state and wait for the running action instruction; After the running action is completed, it enters the ready state and waits for the running action instruction, and the cycle continues.

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