High-power stepless magnetic damping device and power control method thereof

Abstract

The invention discloses a high-power stepless magnetic damping device and a power control method thereof.The high-power stepless magnetic damping device comprises a magnetic resistance magnetic core mechanism, the magnetic resistance magnetic core mechanism achieves control over high-power stepless magnetic damping according to the electromagnetic damping principle, regulation and control response is fast, continuity of constant-power output is guaranteed, and the high-power stepless magnetic damping device is suitable for large-power stepless magnetic damping. And a circle of Halbach magnet array formed by reinforcing magnets is arranged, so that the field intensity in the unit direction is enhanced, and the generation of high-power magnetic damping is realized. According to the power control method, a static Kalman data fusion updating model is introduced for power updating, speed and accuracy are balanced, a PWM signal is output through a PID controller to adjust the input current of a control coil, and therefore the size of a magnetic field is controlled, control over the size of magnetic damping is achieved, stepless regulation and control are achieved, and the control precision is improved. Therefore, stable output of constant power is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of fitness equipment, and particularly to a high-power stepless magnetic damping device and its power control method. Background Art

[0002] The power bike is one of the important devices for aerobic capacity testing and rehabilitation training in the field of sports science. It calculates the metabolic equivalent at a specific power by presetting the power output and combining with the weight of the tester. Further, using the metabolic equivalent value and its corresponding heart rate based on the two-stage power test, the cardiorespiratory function limit of the tester, i.e., the maximum oxygen uptake, can be calculated. During the implementation of the two-stage power test, first, the target power of the power bike needs to be set, and the tester is required to pedal the power bike at a fixed speed. However, in actual operation, it is often difficult for the tester to pedal the power bike at a fixed speed. Therefore, to ensure the accuracy of the measured maximum oxygen uptake data, the power bike needs to automatically adjust the damping of the damping mechanism on the power bike according to the current pedaling speed of the user, so that the power bike maintains the set power. However, the existing damping mechanisms on power bikes are not intelligent enough, and their accuracy, continuity, and feedback are poor, unable to achieve high-power resistance output and intelligent control. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high-power stepless magnetic damping device and its power control method. By adopting the electromagnetic damping principle, the control method combines rapidity and accuracy, solves the defects of lag or insufficient accuracy in the traditional single-feedback system, improves the robustness of the magnetic damping device, and significantly enhances the accuracy, rapid response, and continuity of the magnetic damping device control.

[0004] The technical solution of the present invention is as follows:

[0005] A high-power stepless magnetic damping device includes a box body, a magnetic resistance magnetic core mechanism, a data acquisition mechanism, and a power controller;

[0006] The magnetic resistance magnetic core mechanism includes a main shaft, a rotating wheel disc, a magnetic damping disc, a ring of magnetic cores, coils, and a ring of enhanced magnets. The two ends of the main shaft are rotatably connected to the box body. The rotating wheel disc and the magnetic damping disc are arranged in parallel in the box body and their inner surfaces face each other. The rotating wheel disc is locked and connected to the main shaft through a one-way bearing. The magnetic damping disc is relatively rotatably connected to the main shaft. A ring of annularly distributed magnetic cores is fixed on the inner surface of the magnetic damping disc. The coils are sequentially wound around each magnetic core and connected to the power controller outside the box body. There is a gap between the ring of magnetic cores and the inner surface of the rotating wheel disc. An enhanced magnet is arranged between every two adjacent magnetic cores. Each enhanced magnet is arranged parallel to the magnetic damping disc and fixed between two adjacent coils. The magnetizing surfaces of each enhanced magnet are different, so that the ring of enhanced magnets forms a Halbach magnet array;

[0007] The data acquisition mechanism described above includes a sensor bracket fixedly arranged inside the box, a speed measurement sensor, and a pressure sensor. The speed measurement sensor includes a Hall sensor and a speed measurement magnet. The speed measurement magnet is fixedly connected to the rotating wheel disc and adjacent to the outer periphery of the rotating wheel disc. The Hall sensor is fixedly connected to the sensor bracket and located outside the speed measurement magnet. The fixed end of the pressure sensor is fixedly connected to the sensor bracket. The pressure sensor fixing seat is located between two adjacent magnetic cores and fixedly connected to the inner surface of the magnetic damping disc. The force-receiving end of the pressure sensor is fixedly connected to the pressure sensor fixing seat. The Hall sensor and the pressure sensor are respectively connected to the power controller.

[0008] Each of the magnetic cores described above is of a trapezoidal block structure, and the side with a narrower bottom faces the extension line of the axis of the magnetic damping disc. The four corners of the trapezoidal surface of the magnetic core are all of an arc chamfer structure.

[0009] The coil is an enameled wire without interruption. That is, after the coil winds around the first iron core clockwise without interruption, it winds around the second iron core clockwise until all the iron cores are wound. The number of turns of the coil wound around each magnetic core is 200 - 300 turns. The two ends of the coil are led out of the box and connected to the power controller outside the box.

[0010] Each of the enhancement magnets described above is fixedly positioned between two adjacent coils through epoxy resin curing.

[0011] Both the rotating wheel disc and the magnetic damping disc are of an annular disc structure. A wheel disc bushing is fixedly connected to the inner ring of the rotating wheel disc. The wheel disc bushing is sleeved on the main shaft. A one-way bearing and a two-way bearing are connected between the inner wall of the wheel disc bushing and the outer wall of the main shaft, and the one-way bearing and the two-way bearing are respectively adjacent to the two ends of the wheel disc bushing. The rotation direction of the main shaft is consistent with the locking direction of the one-way bearing, so that the rotating wheel disc is locked and connected to the main shaft through the one-way bearing. The magnetic damping disc is sleeved outside the wheel disc bushing. The inner ring of the magnetic damping disc is rotationally connected to the outer wall of the wheel disc bushing through a magnetic damping bearing, so that the magnetic damping disc is rotationally connected to the main shaft relatively. And a locking nut is threadedly connected to the wheel disc bushing to axially limit the inner ring of the magnetic damping bearing.

[0012] The box body is provided with a tensioning mechanism, which includes a tensioning spring, a tensioning connecting plate and a tensioning wheel. The bottom end of the tensioning spring is fixed to the bottom plate of the box body, and a vertically extending guide hole is provided on the side plate of the box body. The tensioning connecting plate is slidably arranged in the guide hole. A tensioning wheel is provided on the top end of the tensioning connecting plate. The tensioning wheel is eccentrically arranged on the outer periphery of the main shaft. A row of adjustment holes is provided on the bottom end of the tensioning connecting plate, and the row of adjustment holes extends from the bottom end of the tensioning connecting plate to the top end. The top end of the tensioning spring is hung on one of the adjustment holes, and the support and positioning of the tensioning connecting plate is realized by the tensioning spring; the transmission belt is wound around the tensioning wheel, the main shaft and the driving wheel, and the driving wheel drives the main shaft to rotate through the transmission belt, and the tensioning wheel adjusts the transmission belt for tensioning.

[0013] The power controller includes a single-chip microcomputer and a coil drive and current feedback circuit. The coil drive and current feedback circuit includes a MOS tube driver, an N-channel MOS tube, a sampling resistor connected in series to the coil, and a current detection amplifier connected to the sampling resistor. The PWM signal output end of the single-chip microcomputer is connected to the input end of the MOS tube driver, the output end of the MOS tube driver is connected to the gate of the N-channel MOS tube, the source of the N-channel MOS tube is grounded, and the drain of the N-channel MOS tube is connected to the power supply through the series-connected coil and the sampling resistor. When the N-channel MOS tube is turned on, the coil is energized, and the current detection amplifier detects the voltage drop of the sampling resistor to obtain the current current of the coil; the Hall sensor and the pressure sensor are respectively connected to the corresponding sampling ends of the single-chip microcomputer, so that the single-chip microcomputer can know the rotation speed of the rotating wheel and the pressure value applied to the pressure sensor by the magnetic damping disk.

[0014] A power control method for a high-power stepless magnetic damping device specifically comprises the following steps:

[0015] (1) First, calibrate the current and power curve model. By measuring the power of the high-power stepless magnetic damping device when the coil is under different current conditions, the current and power curve diagram is obtained, thereby calibrating the current and power curve model;

[0016] (2) The host computer sends the target power to the single-chip microcomputer, the sampling resistor collects the current current value of the coil in real time, the Hall sensor collects the speed of the rotating wheel in real time, the pressure sensor collects the pressure value applied to the pressure sensor by the magnetic damping disk, and the single-chip microcomputer obtains the current current value, or the speed and pressure value at a fixed time;

[0017] (3) When the MCU obtains the current current value, the corresponding power Z1 is obtained through the current and power curve model, and then the power Z1 is input into the static Kalman data fusion update model to update the power and output the updated power P0;

[0018] (4) When the single chip microcomputer obtains the speed and pressure values, the corresponding power Z2 is calculated according to the following formula (1), and then the power Z2 is input into the static Kalman data fusion update model to update the power and output the updated power P0;

[0019] Z2=T×ω=T×2×π×n / 60=F×L×2×π×n / 60 (1);

[0020] In formula (1), T represents torque; ω represents angular velocity, in rad / s; n represents the rotation speed collected by the Hall sensor, in r / min; F represents the pressure value collected by the pressure sensor, and L represents the force arm of the pressure sensor, which is the measured constant value;

[0021] (5) The MCU compares the updated power P0 with the target power P target The difference operation is performed to obtain the power adjustment value, and then the PID controller of the microcontroller adjusts the PWM duty cycle of the PWM signal according to the power adjustment value, thereby controlling the size of the coil input current and realizing constant power regulation.

[0022] The steps of updating the power of the static Kalman data fusion update model are as follows:

[0023] S1, system initialization: initialize power value x0 = 0; initialize covariance p0; initialize noise variance R1 corresponding to power Z1 and noise variance R2 corresponding to power Z2; initialize PID parameters, i.e. proportional gain Kp, integral gain Ki and differential gain Kd; initialize speed monitoring, collect the speed of the rotating wheel in real time; set target power P target Initialize two timers and set the scanning cycles of the two timers respectively. One timer is used for the microcontroller to obtain the current current value regularly, and the corresponding power Z1 is obtained through the current and power curve model. The other timer is used for the microcontroller to obtain the speed and pressure values ​​regularly, and the corresponding power Z2 is calculated.

[0024] S2. When one of the timers is interrupted, the current current value is collected, and the power Z1 at the current moment is obtained using the power and current curve model. Then, the Kalman gain is calculated according to the following formula (2):

[0025] K1=p0 / (p0+R1) (2);

[0026] Then the power is updated according to the Kalman gain K1, as shown in the following formula (3):

[0027] x1=x0+K1×(Z1-x0) (3);

[0028] At the same time, the covariance is updated according to the Kalman gain K1, as shown in the following formula (4):

[0029] p1=(1-K1)×p0 (4);

[0030] Finally, the output power P0 is assigned, that is, P0=x1, and the updated power P0 is output;

[0031] S3. When another timer is interrupted, the pressure value F and the speed n are collected, and the power Z2 at the current moment is calculated using formula (1), and then the Kalman gain is calculated according to the following formula (5):

[0032] K2=p1 / (p1+R2) (5);

[0033] Then the power is updated according to the Kalman gain K2, as shown in the following formula (6):

[0034] x2=x1+K2×(Z2-x1) (6);

[0035] At the same time, the covariance is updated according to the Kalman gain K2, as shown in the following formula (7):

[0036] p2=(1-K2)×p1 (7);

[0037] Finally, the output power P0 is assigned, that is, P0=x2, and the updated power P0 is output;

[0038] Among them, when any of the two timers is interrupted and the Kalman gain and power are updated, p0 in formula (2) and p1 in formula (5) are the covariances updated after the last interruption of any timer, and x0 in formula (3) and x1 in formula (6) are the powers updated after the last interruption of any timer. The covariance and power are updated by selecting step S2 or S3, so as to assign a value to the output power and output the updated power P0.

[0039] The calculation process of the PID controller generating the PWM signal according to the power adjustment value is shown in the following formula (8):

[0040]

[0041] In formula (8), u(t) is the output of the PID controller at the current time t, ΔP is the power adjustment value, Kp is the proportional gain, Ki is the integral gain, Kd is the differential gain, Kp, Ki and Kd are all PID parameters of the PID controller, P target is the target power, and P0 is the power after the static Kalman data fusion update model is updated.

[0042] Advantages of the present invention:

[0043] (1) The present invention adopts the magnetic damping principle to generate resistance, achieves the purpose of constant power output, and has a fast control response to ensure the continuity of constant power output.

[0044] (2) The present invention adjusts the magnitude of the input current of the control coil by outputting a PWM signal through a PID controller, thereby controlling the magnitude of the magnetic field and realizing control of the magnitude of the magnetic damping. The PWM duty cycle can divide the effective value of the voltage into 7200 levels, realizing stepless regulation, thereby ensuring stable output of constant power.

[0045] (3) A circle of enhanced magnets in the magnetic resistance core mechanism of the present invention forms a Halbach magnet array, which enhances the field strength in a unit direction and realizes the generation of high-power magnetic damping, so that greater power can be obtained under the same input current, avoiding the use of high current to obtain high power, which causes the magnetic damping device to heat up and brings danger and reduces the service life of the coil.

[0046] (4) The present invention uses a pressure sensor to perform force feedback to calculate power, so that the power calculation is highly accurate and the output power can be obtained without calibration.

[0047] (5) In the process of power update and regulation, the present invention introduces a static Kalman data fusion update model to perform power update, collects and fuses two power measurement values, the power measurement value obtained by the current and power curve model is fast but has errors, and the power measurement value obtained by the pressure sensor and the speed for power calculation is accurate but slow, balances the advantages and disadvantages of the two power measurement value acquisition, and uses a static Kalman algorithm to optimize the updated power, updates the covariance through the noise variance, compensates for the parameter deviation caused by the temperature drift of the power measurement value and the mechanical wear of the magnetic damping device, balances the speed and accuracy, and combines the PID closed-loop control to achieve a fast and accurate power control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a perspective view of the present invention.

[0049] Figure 2 It is a schematic diagram of the structure in the box of the present invention.

[0050] Figure 3 It is a structural schematic diagram of the magnetic resistance core mechanism after the rotating wheel disc is removed from the box body of the present invention.

[0051] Figure 4 It is a cross-sectional view of the reluctance core mechanism of the present invention.

[0052] Figure 5 It is a principle block diagram of the power controller of the present invention.

[0053] Figure 6 It is a circuit diagram of the coil drive and current feedback circuit of the present invention.

[0054] Reference numerals: 1 - housing, 11 - guiding hole, 21 - main shaft, 22 - rotating wheel disc, 23 - magnetic damping disc, 24 - magnetic core, 25 - coil, 26 - enhancing magnet, 27 - wheel disc bushing, 28 - one-way bearing, 29 - two-way bearing, 210 - magnetic damping bearing, 211 - locking nut, 212 - pulley, 31 - sensor bracket, 32 - Hall sensor, 33 - speed measuring magnet, 34 - pressure sensor, 35 - pressure sensor fixing seat, 41 - tension spring, 42 - tension connecting plate, 43 - tension pulley, 44 - adjusting hole, 51 - single-chip microcomputer, 52 - coil driving and current feedback circuit. Specific embodiments

[0055] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0056] See Figures 1-4 , a high-power stepless magnetic damping device, comprising a housing 1, a magnetoresistive magnetic core mechanism, a data acquisition mechanism, a tensioning mechanism and a power controller, and the top of the housing 1 is an open structure;

[0057] The magnetoresistive magnetic core mechanism includes a main shaft 21, a rotating wheel disc 22, a magnetic damping disc 23, a ring of magnetic cores 24, a coil 25, and a ring of enhancement magnets 26. The two ends of the main shaft 21 are rotatably connected to the box body 1. The rotating wheel disc 22 and the magnetic damping disc 23 are both of annular disc structures and are arranged in parallel with their inner surfaces facing each other. A wheel disc bushing 27 is fixedly connected to the inner ring of the rotating wheel disc 22. The wheel disc bushing 27 is sleeved on the main shaft 21. A one-way bearing 28 and a two-way bearing 29 are connected between the inner wall of the wheel disc bushing 27 and the outer wall of the main shaft 21, and the one-way bearing 28 and the two-way bearing 29 are respectively adjacent to the two ends of the wheel disc bushing 27. The rotation direction of the main shaft 21 is the same as the locking direction of the one-way bearing 28, so that the rotating wheel disc 22 is locked to the main shaft 21 through the one-way bearing 28, and the two-way bearing 29 realizes the supporting function. The magnetic damping disc 23 is sleeved outside the wheel disc bushing 27. The inner ring of the magnetic damping disc 23 is rotatably connected to the outer wall of the wheel disc bushing 27 through a magnetic damping bearing 210, so that the magnetic damping disc 23 is relatively rotatably connected to the main shaft 21. And a locking nut 211 is threadedly connected to the wheel disc bushing 27 to axially limit the inner ring of the magnetic damping bearing 210. Eighteen magnetic cores 24 distributed in a ring are fixed on the inner surface of the magnetic damping disc 23. Each magnetic core 24 is of a trapezoidal block structure, and the side with the narrower bottom faces the extension line of the axis of the magnetic damping disc 23. The four corners of the trapezoidal surface of the magnetic core 24 are all of arc chamfer structures, which is convenient for the winding of the coil 25 and prevents the cutting of the coil 25. The coil 25 is an enameled wire with a wire diameter of 0.5 mm, an insulation class of H, and no broken wire. That is, after the coil 25 winds around the first iron core 24 clockwise, it winds around the second iron core 24 clockwise without breaking the wire until all the iron cores 24 are wound. The number of turns of the coil wound on each magnetic core 24 is 200 - 300 turns. The two ends of the coil 25 are led out of the box body 1 and connected to a power controller outside the box body 1. A gap not greater than 3 mm is left between the ring of magnetic cores 24 and the inner surface of the rotating wheel disc 22. One enhancement magnet 26 is arranged between every two adjacent magnetic cores 24, with a total of eighteen enhancement magnets 26. Each enhancement magnet 26 is arranged parallel to the magnetic damping disc 23 and is fixed between two adjacent coils 25 by epoxy resin curing. The magnetizing surfaces of each enhancement magnet 26 are different, so that the ring of enhancement magnets 26 forms a Halbach magnet array;

[0058] The data acquisition mechanism includes a sensor bracket 31 fixedly connected to the inside of the box body 1 through an adapter fixing block, a speed measurement sensor, and a pressure sensor 34. The speed measurement sensor includes a Hall sensor 32 and four speed measurement magnets 33. The four speed measurement magnets 33 are fixedly connected to the rotary wheel 22 and adjacent to the outer periphery of the rotary wheel 22, and the four speed measurement magnets 33 are evenly arranged along the circumference of the rotary wheel 22. The Hall sensor 32 is fixedly connected to the sensor bracket 31 and located outside the four speed measurement magnets 33. The fixed end of the pressure sensor 34 is fixedly connected to the sensor bracket 31. The pressure sensor fixing seat 35 is located between two adjacent magnetic cores 24 and fixedly connected to the inner surface of the magnetic damping disc 23. The force-receiving end of the pressure sensor 34 is fixedly connected to the pressure sensor fixing seat 35;

[0059] The tensioning mechanism includes a tensioning spring 41, a tensioning connecting plate 42, and a tensioning wheel 43. The bottom end of the tensioning spring 41 is fixed to the bottom plate of the box body 1. A vertically extending guide hole 11 is provided on the side plate of the box body 1. The tensioning connecting plate 42 is slidably arranged in the guide hole 11, so that the tensioning connecting plate 42 can slide up and down along the guide hole 11. A tensioning wheel 43 is provided at the top end of the tensioning connecting plate 42. The tensioning wheel 43 is eccentrically arranged on the outer periphery of the main shaft 21. A row of adjustment holes 44 is provided at the bottom end of the tensioning connecting plate 42. The row of adjustment holes 44 extends from the bottom end to the top end of the tensioning connecting plate 42. The top end of the tensioning spring 41 is hung on one of the adjustment holes 44 to realize the support and positioning of the tensioning connecting plate 42 through the tensioning spring 41. A pulley 212 (specifically a multi-wedge pulley) is fixedly provided at the end of the main shaft 21 extending out of the box body. A transmission belt (specifically a multi-wedge belt) is wound around the tensioning wheel 43, the pulley 212, and the driving wheel. The driving wheel drives the pulley 212 through the transmission belt, and the pulley 212 drives the main shaft 21 to rotate. The tensioning wheel 43 adjusts the tension of the transmission belt.

[0060] See Figure 5 and Figure 6, the power controller includes a single-chip microcomputer 51 and a coil drive and current feedback circuit 52. The coil drive and current feedback circuit 52 includes an MOS transistor driver U1 (model TC4422AVOA713), an N-channel MOS transistor Q1 (model IRF540N), a sampling resistor R1 connected in series to the coil 25, and a current detection amplifier U2 (model INA240A1PWR) connected to the sampling resistor R1. The PWM signal output terminal of the single-chip microcomputer 51 is connected to the input terminal of the MOS transistor driver U1. The output terminal of the MOS transistor driver U1 is connected to the gate of the N-channel MOS transistor Q1. The source of the N-channel MOS transistor Q1 is grounded. The drain of the N-channel MOS transistor Q1 is connected to the 24V power supply through the series-connected coil 25 and sampling resistor R1. When the N-channel MOS transistor Q1 is turned on, the coil 25 is energized. The current detection amplifier U2 detects the voltage drop across the sampling resistor R1 to obtain the current of the coil 25. The PWM signal is divided into 7200 levels of duty cycle, that is, the effective voltage value is divided into 7200 levels, corresponding to the adjustment of the 0-24V voltage, that is, the 24V is divided into 7200 levels, and the duty cycle of 0-7200 is adjusted through PWM; the Hall sensor 32 and the pressure sensor 34 are respectively connected to the corresponding acquisition terminals of the single-chip microcomputer 51, so that the single-chip microcomputer 51 can know the rotation speed of the rotating wheel 22 and the pressure value applied by the magnetic damping disk 23 to the pressure sensor 34.

[0061] Working principle of the high-power stepless magnetic damping device:

[0062] While the main shaft 21 drives the rotating wheel 22 to rotate, the coil 25 of the reluctance magnetic core mechanism is energized. The rotating rotating wheel 22 cuts the magnetic field lines generated by the energization, and a force that hinders the rotation of the rotating wheel 22 will be generated on the magnetic damping disk 23 of the reluctance magnetic core mechanism; since the force-receiving end of the pressure sensor 34 is fixedly connected to the magnetic damping disk 23 through the pressure sensor fixing seat 35, all the rotating force of the magnetic damping disk 23 acts on the pressure sensor 34, that is, the resistance of the magnetic damping disk 23 to the metal flywheel 1 is equal to the force exerted by the magnetic damping disk 23 on the pressure sensor 34.

[0063] A power control method for a high-power stepless magnetic damping device specifically includes the following steps:

[0064] (1). First, calibrate the current-power curve model. By measuring the power of the high-power stepless magnetic damping device when the coil 25 is under different current conditions, obtain the current-power curve graph, and thus calibrate the current-power curve model;

[0065] (2). The host computer sends the target power P to the single-chip microcomputer 51 target, the sampling resistor R1 collects the current value of the coil 25 in real time, the Hall sensor 32 collects the rotational speed of the rotating wheel 22 in real time, the pressure sensor 34 collects the pressure value applied by the magnetic damping disc 23 to the pressure sensor 34, and the single-chip microcomputer 51 obtains the current value, or the rotational speed and pressure value at regular intervals;

[0066] (3), when the single-chip microcomputer 51 obtains the current value, the corresponding power Z1 is obtained through the current-power curve model, and then the power Z1 is input into the static Kalman data fusion update model for power update, and the updated power P0 is output;

[0067] (4), when the single-chip microcomputer 51 obtains the rotational speed and pressure value, the corresponding power Z2 is calculated according to the following formula (1), and then the power Z2 is input into the static Kalman data fusion update model for power update, and the updated power P0 is output;

[0068] Z2 = T×ω = T×2×π×n / 60 = F×L×2×π×n / 60 (1);

[0069] In formula (1), T represents torque; ω represents angular velocity, with the unit of rad / s; n represents the rotational speed collected by the Hall sensor, with the unit of r / min; F represents the pressure value collected by the pressure sensor, and L represents the force arm of the pressure sensor, and the force arm is a measured fixed value;

[0070] The steps for the static Kalman data fusion update model to perform power update are as follows:

[0071] S1. System initialization: Initialize the power value x0 = 0; Initialize the covariance p0; Initialize the noise variance R1 corresponding to the power Z1 and the noise variance R2 corresponding to the power Z2; Initialize the PID parameters, namely the proportional gain Kp, the integral gain Ki, and the derivative gain Kd; Initialize the rotational speed monitoring to collect the rotational speed of the rotating wheel in real time; Set the target power P target ; Initialize two timers, and set the scan periods of the two timers respectively. One timer (scan period 1ms) is used for the single-chip microcomputer 51 to obtain the current value at regular intervals and obtain the corresponding power Z1 through the current-power curve model, and the other timer (scan period 100ms) is used for the single-chip microcomputer 51 to obtain the rotational speed and pressure value at regular intervals and calculate the corresponding power Z2;

[0072] S2. When one of the timers interrupts, the current value is collected, and the power Z1 at the current moment is obtained using the power-current curve model, and then the Kalman gain is calculated according to the following formula (2):

[0073] K1 = p0 / (p0 + R1) (2);

[0074] Then update the power according to the Kalman gain K1, as shown in the following formula (3):

[0075] x1 = x0 + K1 × (Z1 - x0) (3);

[0076] At the same time, update the covariance according to the Kalman gain K1, as shown in the following formula (4):

[0077] p1 = (1 - K1) × p0 (4);

[0078] Finally, assign the output power P0, that is, make P0 = x1, and output the updated power P0;

[0079] S3. When another timer interrupts, collect the pressure value F and the rotational speed n, calculate the power Z2 at the current moment using formula (1), and then calculate the Kalman gain according to the following formula (5):

[0080] K2 = p1 / (p1 + R2) (5);

[0081] Then update the power according to the Kalman gain K2, as shown in the following formula (6):

[0082] x2 = x1 + K2 × (Z2 - x1) (6);

[0083] At the same time, update the covariance according to the Kalman gain K2, as shown in the following formula (7):

[0084] p2 = (1 - K2) × p1 (7);

[0085] Finally, assign the output power P0, that is, make P0 = x2, and output the updated power P0;

[0086] Among them, when any one of the two timers interrupts and performs the Kalman gain and power update calculations, p0 in formula (2) and p1 in formula (5) are both the covariance updated after the previous interruption of any one of the timers, x0 in formula (3) and x1 in formula (6) are both the power updated after the previous interruption of any one of the timers. The covariance and power are updated by selecting step S2 or S3, so as to assign the output power and output the updated power P0;

[0087] (5). The single-chip microcomputer 51 calculates the difference between the updated power P0 and the target power P target to obtain the power adjustment value. Then, the PID controller of the single-chip microcomputer 51 adjusts the PWM duty cycle of the PWM signal according to the power adjustment value, so as to control the magnitude of the coil input current and achieve constant power regulation; among them, the calculation process of the PID controller generating the PWM signal according to the power adjustment value is shown in the following formula (8):

[0088]

[0089] In Equation (8), u(t) is the output of the PID controller at the current moment t, ΔP is the power adjustment value, Kp is the proportional gain, Ki is the integral gain, Kd is the derivative gain, and Kp, Ki, and Kd are all PID parameters of the PID controller. P target is the target power, and P0 is the power after being updated by the static Kalman data fusion update model.

[0090] Performance analysis:

[0091] I. Magnetic field intensity comparison experiment:

[0092] Control group: Traditional magnetoresistive device (Patent CN202111510136.3), measured magnetic field intensity 0.8T;

[0093] Example group of the present invention: Measured magnetic field intensity 1.12T (a 40% increase).

[0094] The data is sourced from measurements made using a TD8650 model teslameter from Changsha Tianheng Surveying and Mapping Technology Co., Ltd.

[0095] II. Constant power mode test:

[0096] Conditions: Target power 500W, load fluctuation range ±10%;

[0097] Test results of the example group of the present invention: Output power 498W - 502W (deviation < ±0.4%).

[0098] III. Environmental adaptability verification:

[0099] Vibration resistance performance of the example group of the present invention: Under random vibration of 10Hz - 200Hz, the power deviation <

[0100] ±0.8%.

[0101] The above experimental results demonstrate that the high-power stepless magnetic damping device disclosed in the examples of the present invention has a large magnetic field intensity, a small output deviation in the constant power mode, and excellent vibration resistance performance.

[0102] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-power stepless magnetic damping device, characterized in that: It includes a box body, a magnetic resistance core mechanism, a data acquisition mechanism and a power controller; The magnetic resistance core mechanism includes a main shaft, a rotating wheel, a magnetic damping disk, a circle of magnetic cores, a coil and a circle of enhanced magnets. The two ends of the main shaft are rotatably connected to the box body. The rotating wheel and the magnetic damping disk are arranged in parallel in the box body and the inner surfaces are opposite. The rotating wheel is locked and connected to the main shaft through a one-way bearing. The magnetic damping disk is relatively rotatably connected to the main shaft. A circle of annularly distributed magnetic cores is fixed on the inner surface of the magnetic damping disk. The coil is sequentially wound around each magnetic core and connected to a power controller outside the box. A gap is left between a circle of magnetic cores and the inner surface of the rotating wheel. An enhanced magnet is arranged between every two adjacent magnetic cores. Each enhanced magnet is arranged parallel to the magnetic damping disk and fixed between two adjacent coils. The magnetizing surface of each enhanced magnet is different, so that a circle of enhanced magnets constitutes a Halbach magnet array. The data acquisition mechanism includes a sensor bracket fixedly arranged in the box, a speed sensor and a pressure sensor. The speed sensor includes a Hall sensor and a speed magnet. The speed magnet is fixedly connected to the rotating wheel and is adjacent to the outer periphery of the rotating wheel. The Hall sensor is fixedly connected to the sensor bracket and is located at the outer periphery of the speed magnet. The fixed end of the pressure sensor is fixedly connected to the sensor bracket. The pressure sensor fixing seat is located between two adjacent magnetic cores and is fixedly connected to the inner surface of the magnetic damping disk. The force-bearing end of the pressure sensor is fixedly connected to the pressure sensor fixing seat. The Hall sensor and the pressure sensor are respectively connected to the power controller.

2. A high-power stepless magnetic damping device according to claim 1, characterized in that: Each of the magnetic cores is a trapezoidal block structure, with the narrow side of the bottom facing the extended axis of the magnetic damping disk, and the four corners of the trapezoidal surface of the magnetic core are all arc chamfered structures.

3. A high-power stepless magnetic damping device according to claim 1, characterized in that: The coil is an unbroken enameled wire, that is, after the coil is wound clockwise around the first iron core, the second iron core is wound clockwise without interruption until all the iron cores are wound. The number of turns of the coil on each magnetic core is 200-300 turns, and both ends of the coil are led out of the box and connected to the power controller outside the box.

4. A high-power stepless magnetic damping device according to claim 1, characterized in that: Each of the enhanced magnets is positioned between two adjacent coils by curing epoxy resin.

5. A high-power stepless magnetic damping device according to claim 1, characterized in that: The rotating wheel disc and the magnetic damping disc are both annular disc structures. A wheel disc sleeve is fixedly connected to the inner ring of the rotating wheel disc, and the wheel disc sleeve is sleeved on the main shaft. A one-way bearing and a two-way bearing are connected between the inner wall of the wheel disc sleeve and the outer wall of the main shaft, and the one-way bearing and the two-way bearing are respectively adjacent to the two ends of the wheel disc sleeve. The rotation direction of the main shaft is consistent with the locking direction of the one-way bearing, so that the rotating wheel disc is locked and connected to the main shaft through the one-way bearing, and the magnetic damping disc is sleeved outside the wheel disc sleeve, and the inner ring of the magnetic damping disc is rotatably connected to the outer wall of the wheel disc sleeve through the magnetic damping bearing, so that the magnetic damping disc is rotatably connected to the main shaft relative to the main shaft, and a locking nut is threadedly connected to the wheel disc sleeve to axially limit the inner ring of the magnetic damping bearing.

6. A high-power stepless magnetic damping device according to claim 1, characterized in that: The box body is provided with a tensioning mechanism, which includes a tensioning spring, a tensioning connecting plate and a tensioning wheel. The bottom end of the tensioning spring is fixed to the bottom plate of the box body, and a vertically extending guide hole is provided on the side plate of the box body. The tensioning connecting plate is slidably arranged in the guide hole. A tensioning wheel is provided on the top end of the tensioning connecting plate. The tensioning wheel is eccentrically arranged on the outer periphery of the main shaft. A row of adjustment holes is provided on the bottom end of the tensioning connecting plate, and the row of adjustment holes extends from the bottom end of the tensioning connecting plate to the top end. The top end of the tensioning spring is hung on one of the adjustment holes, and the support and positioning of the tensioning connecting plate is realized by the tensioning spring; the transmission belt is wound around the tensioning wheel, the main shaft and the driving wheel, and the driving wheel drives the main shaft to rotate through the transmission belt, and the tensioning wheel adjusts the transmission belt for tensioning.

7. A high-power stepless magnetic damping device according to claim 1, characterized in that: The power controller includes a single-chip microcomputer and a coil drive and current feedback circuit. The coil drive and current feedback circuit includes a MOS tube driver, an N-channel MOS tube, a sampling resistor connected in series to the coil, and a current detection amplifier connected to the sampling resistor. The PWM signal output end of the single-chip microcomputer is connected to the input end of the MOS tube driver, the output end of the MOS tube driver is connected to the gate of the N-channel MOS tube, the source of the N-channel MOS tube is grounded, and the drain of the N-channel MOS tube is connected to the power supply through the series-connected coil and the sampling resistor. When the N-channel MOS tube is turned on, the coil is energized, and the current detection amplifier detects the voltage drop of the sampling resistor to obtain the current current of the coil; the Hall sensor and the pressure sensor are respectively connected to the corresponding sampling ends of the single-chip microcomputer, so that the single-chip microcomputer can know the rotation speed of the rotating wheel and the pressure value applied to the pressure sensor by the magnetic damping disk.

8. The power control method of a high-power stepless magnetic damping device according to claim 7, characterized in that: The specific steps include: (1) First, calibrate the current and power curve model. By measuring the power of the high-power stepless magnetic damping device when the coil is under different current conditions, the current and power curve diagram is obtained, thereby calibrating the current and power curve model; (2) The host computer sends the target power to the single-chip microcomputer, the sampling resistor collects the current current value of the coil in real time, the Hall sensor collects the speed of the rotating wheel in real time, the pressure sensor collects the pressure value applied to the pressure sensor by the magnetic damping disk, and the single-chip microcomputer obtains the current current value, or the speed and pressure value at a fixed time; (3) When the MCU obtains the current current value, the corresponding power Z1 is obtained through the current and power curve model, and then the power Z1 is input into the static Kalman data fusion update model to update the power and output the updated power P0; (4) When the single chip microcomputer obtains the speed and pressure values, the corresponding power Z2 is calculated according to the following formula (1), and then the power Z2 is input into the static Kalman data fusion update model to update the power and output the updated power P0; Z2=T×ω=T×2×π×n / 60=F×L×2×π×n / 60 (1); In formula (1), T represents torque; ω represents angular velocity, in rad / s; n represents the rotation speed collected by the Hall sensor, in r / min; F represents the pressure value collected by the pressure sensor, and L represents the force arm of the pressure sensor, which is the measured constant value; (5) The MCU compares the updated power P0 with the target power P target The difference operation is performed to obtain the power adjustment value, and then the PID controller of the microcontroller adjusts the PWM duty cycle of the PWM signal according to the power adjustment value, thereby controlling the size of the coil input current and realizing constant power regulation.

9. The power control method according to claim 8, characterized in that: The steps of updating the power of the static Kalman data fusion update model are as follows: S1, system initialization: initialize power value x0 = 0; initialize covariance p0; initialize noise variance R1 corresponding to power Z1 and noise variance R2 corresponding to power Z2; initialize PID parameters, i.e. proportional gain Kp, integral gain Ki and differential gain Kd; initialize speed monitoring, collect the speed of the rotating wheel in real time; set target power P target Initialize two timers and set the scanning cycles of the two timers respectively. One timer is used for the microcontroller to obtain the current current value regularly, and the corresponding power Z1 is obtained through the current and power curve model. The other timer is used for the microcontroller to obtain the speed and pressure values ​​regularly, and the corresponding power Z2 is calculated. S2. When one of the timers is interrupted, the current current value is collected, and the power Z1 at the current moment is obtained using the power and current curve model. Then, the Kalman gain is calculated according to the following formula (2): K1=p0 / (p0+R1) (2); Then the power is updated according to the Kalman gain K1, as shown in the following formula (3): x1=x0+K1×(Z1-x0) (3); At the same time, the covariance is updated according to the Kalman gain K1, as shown in the following formula (4): p1=(1-K1)×p0 (4); Finally, the output power P0 is assigned, that is, P0=x1, and the updated power P0 is output; S3. When another timer is interrupted, the pressure value F and the speed n are collected, and the power Z2 at the current moment is calculated using formula (1), and then the Kalman gain is calculated according to the following formula (5): K2=p1 / (p1+R2) (5); Then the power is updated according to the Kalman gain K2, as shown in the following formula (6): x2=x1+K2×(Z2-x1) (6); At the same time, the covariance is updated according to the Kalman gain K2, as shown in the following formula (7): p2=(1-K2)×p1 (7); Finally, the output power P0 is assigned, that is, P0=x2, and the updated power P0 is output; Among them, when any of the two timers is interrupted and the Kalman gain and power are updated, p0 in formula (2) and p1 in formula (5) are the covariances updated after the last interruption of any timer, and x0 in formula (3) and x1 in formula (6) are the powers updated after the last interruption of any timer. The covariance and power are updated by selecting step S2 or S3, so as to assign a value to the output power and output the updated power P0.

10. The power control method according to claim 9, characterized in that: The calculation process of the PID controller generating the PWM signal according to the power adjustment value is shown in the following formula (8): In formula (8), u(t) is the output of the PID controller at the current time t, ΔP is the power adjustment value, Kp is the proportional gain, Ki is the integral gain, Kd is the differential gain, Kp, Ki and Kd are all PID parameters of the PID controller, P target is the target power, and P0 is the power after the static Kalman data fusion update model is updated.

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