Simulation device, program, and simulation method

Abstract

To provide a simulation device capable of effectively simulating the behavior of a DC motor with a brush.SOLUTION: A simulation device (1) includes a model storage unit (2) in which a motor physical model (211) obtained by modeling a brushed motor (20) is stored, and a model computation unit (3) configured to perform computation processing using the motor physical model, wherein the motor physical model includes a winding circuit portion (2111B) obtained by modeling permanent magnets (Mg), windings (WR), commutators (CM) connected to the windings, and brushes (BR) configured to be able to come into contact with the commutators in the brushed motor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a simulation device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a brushed DC (direct current) motor (hereinafter referred to as a BDC motor) having brushes and a commutator has been known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-56913

[0004] [overview] To simulate the behavior of a BDC motor, a motor model that models the BDC motor is required. Conventional general-purpose motor models reproduce steady-state characteristics as average values, and do not reproduce periodic / transient characteristics such as current ripple. On the other hand, motor models that utilize electromagnetic field analysis based on finite elements reproduce phenomena with high accuracy, but have the problem of requiring a huge amount of calculations and long simulation times.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a simulation device that can effectively simulate the behavior of a BDC motor.

[0006] A simulation device according to one aspect of the present disclosure includes: a model storage unit that stores a motor physical model that models a brushed motor; a model calculation unit configured to perform calculation processing using the motor physical model; Equipped with The motor physical model has a winding circuit section that models the permanent magnets, windings, commutator segments connected to the windings, and brushes that are configured to be able to come into contact with the commutator segments in the brushed motor.

[0007] Another aspect of the present disclosure is a simulation method in which a computer performs calculations using a motor physical model having a winding circuit section that models permanent magnets, windings, commutator segments connected to the windings, and brushes configured to be able to come into contact with the commutator segments in a brushed motor. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a computer according to an exemplary embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a simulation device according to an exemplary embodiment of the present disclosure. [Figure 3] FIG. 3 is a side view (left) and a front view (right) showing a schematic configuration example of a BDC motor. [Figure 4] FIG. 4 is a schematic plan cross-sectional view showing an example of the configuration of a BDC motor. [Figure 5] FIG. 5 is a development view of the configuration shown in FIG. 4 developed in the circumferential direction. [Figure 6] FIG. 6 is a diagram showing the configuration of a motor physical model. [Figure 7] FIG. 7 is a diagram showing an example of a plot of the back electromotive force constant against the rotation speed. [Figure 8] FIG. 8 is a diagram showing an example of a plot of the motor terminal current, the back electromotive force constant, and the motor torque relative to the rotation speed. [Figure 9] FIG. 9 is a diagram showing model parameters in a motor physical model. [Figure 10] FIG. 10 is a diagram showing the gaps between the commutator segments. [Figure 11] FIG. 11 is a diagram for explaining the contact resistance between the commutator segments and the brushes. [Figure 12] FIG. 12 is a diagram showing the rotational movement of the winding sides. [Figure 13] FIG. 13 is a diagram showing an example of a magnetic flux density distribution. [Figure 14]FIG. 14 is a diagram showing the positional deviation between the permanent magnet and the brush. [Figure 15] FIG. 15 is a diagram showing the lengths of the sides of the windings. [Figure 16] FIG. 16 is a diagram showing the distance of the sides of the winding from the axis of rotation. [Figure 17] FIG. 17 is a diagram showing the filter configuration near the motor terminals. [Figure 18] FIG. 18 is a schematic plan view, a perspective view, and a development view showing the rotational movement of the windings. [Figure 19] FIG. 19 is a schematic development showing the rotational movement of the windings. [Figure 20] FIG. 20 is a diagram showing an overall view of the winding circuit section. [Figure 21] FIG. 21 is a table showing a method for calculating contact resistance. [Figure 22] FIG. 22 is a diagram showing the configuration of a motor physical model when modeling is performed using Simscape (registered trademark) / Simulink (registered trademark). [Figure 23] FIG. 23 is a diagram showing a partial configuration of the winding circuit model unit. [Figure 24] FIG. 24 is a diagram illustrating an example of a simulation result. [Figure 25] FIG. 25 is a diagram showing an example of a comparison between a simulation and an actual device.

[0009] [Detailed explanation] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0010] <Computer configuration> 1 is a diagram showing the configuration of a computer 100 according to an exemplary embodiment of the present disclosure. The computer 100 functions as a simulation device according to the present disclosure, which will be described later. The computer 100 is, for example, a PC (personal computer). When the computer 100 is a PC, it does not matter whether it is a desktop computer or a notebook computer.

[0011] The computer 100 includes a CPU (Central Processing Unit) 100A, a memory 100B, an auxiliary storage device 100C, an operation input unit 100D, and a display unit 100E.

[0012] The CPU 100A has a control device and an arithmetic device (neither of which are shown). The control device interprets program instructions and controls each part of the computer 100. The arithmetic device is a device that performs arithmetic processing.

[0013] The memory 100B is a semiconductor storage device that temporarily stores programs or data. The information stored in the memory 100B is erased when the computer 100 is powered off.

[0014] The auxiliary storage device 100C is configured with a hard disk drive (HDD) or a solid state drive (SSD), and stores programs or data. The programs stored in the auxiliary storage device 100C are loaded into the memory 100B. The CPU 100A executes the programs loaded into the memory 100B.

[0015] The operation input unit 100D is configured with a keyboard, a mouse, or the like, and is a device that provides operation input to the computer 100. Information input from the operation input unit 100D is sent to the memory 100B.

[0016] The display unit 100E is configured by, for example, a liquid crystal display, and converts the information acquired from the memory 100B into an image and outputs it.

[0017] <Configuration of the simulation device> 2 is a diagram illustrating a configuration of a simulation device 1 according to an exemplary embodiment of the present disclosure. The simulation device 1 includes a model storage unit 2, a model calculation unit 3, a model setting unit 4, a display control unit 5, an operation input unit 6, and a display unit 7. A program P (FIG. 1) stored in an auxiliary storage device 100C of the computer 100 is a program for causing the computer 100 to function as the simulation device 1.

[0018] The model storage unit 2 stores a motor physical model 211, and is configured by the auxiliary storage device 100C of the computer 100. The motor physical model 211 is configured as a program P using, for example, MATLAB (registered trademark) / Simulink (registered trademark). The motor physical model 211 is a model that models a BDC motor, and details will be described later.

[0019] The functions of the model calculation unit 3, the model setting unit 4, and the display control unit 5 are realized by the CPU 100A executing the program P. The operation input unit 6 and the display unit 7 correspond to the operation input unit 100D and the display unit 100E in the computer 100, respectively.

[0020] The model calculation unit 3 executes a simulation by performing calculation processing on the motor physical model 211 stored in the model storage unit 2. The model setting unit 4 performs settings (parameter settings, etc.) related to the motor physical model 211 in response to input from the operation input unit 6. The simulation by the model calculation unit 3 is performed in accordance with the settings made by the model setting unit 4. The display control unit 5 controls the display unit 7 to display a model setting screen in response to input from the operation input unit 6, or controls the display unit 7 to display the simulation results.

[0021] <Motor physical model> Here, we will explain the motor physical model 211. The motor physical model 211 is a model that is modeled based on the logic of the internal structure of the BDC motor and the physics of the rotation principle.

[0022] <<Motor structure>> FIG. 3 is a side view (left) and a front view (right) showing a schematic configuration example of motor 20, which is a BDC motor. The Cartesian coordinate system shown in FIG. 3 is a stationary coordinate system fixed to base 201. The X-axis, Y-axis, and Z-axis are perpendicular to one another. The Z-axis extends in the direction of axis 20C and passes through the center of axis 20C. The Y-axis extends perpendicular to the plane of base 201. The X-axis extends parallel to the plane and in the horizontal direction. In FIG. 3, as an example, the origin O of the Cartesian coordinate system is included in rotor 20B.

[0023] As shown in FIG. 3, motor 20 is fixed on base 201. Motor 20 has housing 20A, rotor 20B, shaft 20C, stator 20D, and bearing 20E. Rotor 20B, shaft 20C, stator 20D, and bearing 20E are housed inside housing 20A. Stator 20D is fixed to housing 20A and does not rotate. Rotor 20B is located on the inner periphery of stator 20D and is rotatable relative to stator 20D. Shaft 20C protrudes from rotor 20B on both sides in the rotational axis direction (Z-axis direction). Shaft 20C is rotatably supported by bearings 20E on both sides in the rotational axis direction. Bearing 20E is fixed to housing 20A. Note that FIG. 3 illustrates an inner rotor type in which rotor 20B is located on the inner periphery of stator 20D, but an outer rotor type in which the rotor is located on the outer periphery of the stator may also be used.

[0024] Fig. 4 is a schematic plan cross-sectional view showing an example configuration of motor 20. Fig. 4 is a view seen in the direction of rotation axis J. Rotation axis J coincides with the Z axis described above. Note that hereinafter, the direction in which rotation axis J extends will be referred to as the axial direction, the direction around rotation axis J as the circumferential direction, and the direction perpendicular to rotation axis J as the radial direction.

[0025] Stator 20D includes permanent magnets Mg and brushes BR. In the configuration shown in FIG. 4, permanent magnets Mg include magnets MgS1, MgN1, MgS2, and MgN2. Magnets MgS1, MgN1, MgS2, and MgN2 arrange south poles, north poles, south poles, and north poles in the circumferential direction on the radially inner side, respectively. In other words, south poles and north poles are arranged alternately in the circumferential direction on the radially inner side.

[0026] The brushes BR include positive and negative brushes, as will be described later. The brushes have polarities that alternate in the circumferential direction.

[0027] The rotor 20B includes an iron core 202, a winding WR, and commutator bars CM. The iron core 202 is formed, for example, by stacking electromagnetic steel sheets in the axial direction. The iron core 202 is arranged radially inside the permanent magnets Mg. The iron core 202 has an annular portion 202A and teeth 202B. The annular portion 202A extends in the axial direction and is formed in an annular shape in the circumferential direction. The teeth 202B protrude radially outward from the outer circumferential surface of the annular portion 202A. Multiple teeth 202B are arranged in the circumferential direction.

[0028] In the configuration of FIG. 4, the windings WR include windings WR1 to WR16, i.e., 16 windings. Note that FIG. 4 representatively illustrates only windings WR1 to WR4. Each winding WR is wound around a tooth 202B so as to pass through one circumferential side of a certain tooth 202B (illustrated as θ1) and the other circumferential side of a second tooth 202B on the other circumferential side of that tooth 202B. The teeth 202B around which each winding WR is wound are shifted by one in the circumferential direction. In this way, the configuration of FIG. 4 is a concentrated winding configuration.

[0029] The commutator segments CM are arranged radially inward of the iron core 202 and radially outward of the brushes BR. In the configuration of FIG. 4, the commutator segments CM include commutator segments CM1 to CM16 (reference numerals are not shown in FIG. 4), i.e., 16 commutator segments. The commutator segments CM1 to CM16 are arranged in a circular ring shape in the circumferential direction. One end and the other end of the lead wires drawn from each winding WR are connected to the commutator segments CM adjacent in the circumferential direction. The commutator segments CM connected to each winding WR are shifted one from the other in the circumferential direction.

[0030] The commutator segments CM can come into contact with the brushes BR. As the rotor 20B rotates, the commutator segments CM rotate, and which commutator segments CM come into contact with the brushes BR and the contact resistance change over time.

[0031] FIG. 5 is a circumferentially expanded view of the configuration shown in FIG. 4. FIG. 5 shows the rotational direction θrt of the rotor 20B. The rotational direction θrt is the same direction as θ1 on one circumferential side shown in FIG. 4. The south and north poles are arranged along the rotational direction θrt. Furthermore, the commutator segments CM1 to CM16 are arranged along the rotational direction θrt. Specifically, the commutator segments CM16 → CM15 → ... are lined up in the order of commutator segments CM16 → CM15 → ... along the rotational direction θrt, and once commutator segment CM1 is lined up, the sequence returns to commutator segment CM16. In other words, the commutator segments CM are arranged in a loop along the rotational direction θrt.

[0032] As described above, one end of the lead wire drawn from the winding WR is connected to a commutator segment CM adjacent to the winding WR. Specifically, as shown in FIG. 5, one end of the lead wire drawn from the winding WR1 is connected to the commutator segment CM16, and the other end is connected to the commutator segment CM1. One end of the lead wire drawn from the winding WR2 is connected to the commutator segment CM1, and the other end is connected to the commutator segment CM2. One end of the lead wire drawn from the winding WR3 is connected to the commutator segment CM2, and the other end is connected to the commutator segment CM3. One end of the lead wire drawn from the winding WR4 is connected to the commutator segment CM3, and the other end is connected to the commutator segment CM4. Similarly, all the lead wires up to the winding WR16 are connected to the commutator segments CM. Note that FIG. 5 shows only the windings WR1 to WR4 as a representative example. As a result, the windings WR are connected in series via the commutator segments CM, forming a loop circuit.

[0033] The brushes BR include positive brushes BR_P1 and BR_P2 and negative brushes BR_N1 and BR_N2. The negative brush BR_N1, the positive brush BR_P1, the negative brush BR_N2, and the positive brush BR_P2 are arranged in this order along the rotation direction θrt.

[0034] As the rotor 20B rotates, the commutator segments CM1 to CM16 move in the direction of rotation θrt, and the commutator segments CM that contact the positive brushes BR_P1 and BR_P2 and the negative brushes BR_N1 and BR_N2 are switched in sequence. Figure 5 shows, as an example, a state in which the commutator segments CM4 and CM3 are in contact with the negative brush BR_N1, the commutator segments CM16 and CM15 are in contact with the positive brush BR_P1, the commutator segments CM12 and CM11 are in contact with the negative brush BR_N2, and the commutator segments CM8 and CM7 are in contact with the positive brush BR_P2. The winding WR moves in the direction of rotation θrt together with the commutator segments CM, crossing the magnetic flux generated by the magnetic poles.

[0035] <<Overall configuration of the motor physical model>> 6 is a diagram showing the configuration of the motor physical model 211. The motor physical model 211 has an equation of motion part 2111A and a winding circuit part 2111B.

[0036] FIG. 6 is a diagram showing the input / output relationship between the equation of motion unit 2111A and the winding circuit unit 2111B. An input voltage Vin is input to the winding circuit unit 2111B, and a motor terminal current im is calculated and output. The input voltage Vin is applied between the motor positive terminal Tp and the motor negative terminal Tn as shown in FIG. 5, and the motor terminal current im is a current flowing through the motor terminals. The motor terminal current im is input to the equation of motion unit 2111A, and a mechanical angular velocity ωm and a mechanical angle θm of the rotor 20B are calculated and output. The mechanical angular velocity ωm and the mechanical angle θm are fed back to the winding circuit unit 2111B.

[0037] <<About the equation of motion>> The equation of motion unit 2111A has the following equation (1) as the equation of motion.

number

[0038] The motor torque Tm is expressed by the following equation (2).

number

[0039] In a motor, torque is generated by the interaction of the magnetic flux distribution of the permanent magnets and the magnetic flux distribution caused by the winding current. The contribution of the magnetic flux distribution caused by the permanent magnets to torque is determined by the shape and arrangement of the magnetic poles, as well as the geometric arrangement of the windings, and is a constant gain-like contribution that is unrelated to the rotational speed and the motor terminal current. Therefore, as expressed in equation (2) above, motor torque Tm is the product of the torque constant Kt, which is a constant coefficient, and the motor terminal current im.

[0040] Furthermore, the torque constant Kt and the back electromotive force constant Ke have a relationship of Kt = Ke, and the back electromotive force Vbemf and the mechanical angular velocity ωm have a relationship of Vbemf = Ke·ωm. The back electromotive force is the voltage generated across the motor terminals of the motor being modeled when the shaft of the motor being modeled is connected to another motor and the shaft is rotated at a constant speed by the other motor. The back electromotive force Vbemf was measured while changing the rotation speed, and Ke = Vbemf / ωm was calculated. As shown in Figure 7, the back electromotive force constant was almost constant regardless of the rotation speed. Therefore, the back electromotive force constant can be considered a constant, and the average value of the plotted back electromotive force constant was set as the back electromotive force constant Ke. This value can be set as the torque constant Kt. The fact that the back electromotive force constant Ke is a constant provides the basis for equation (2) above.

[0041] In the equation of motion (1) above, the left side represents the product of inertia Jm and mechanical angular acceleration, and the right side represents the combined torque of motor torque Tm generated by application of input voltage Vin to the motor terminals, loss torque Tloss which collectively represents various losses, and external torque Tex. The external torque Tex corresponds to the torque output from the load model and the torque output from a person or the environment.

[0042] Torque loss Tloss is

number

[0043] As mentioned above, the loss torque is assumed to be a quadratic expression of the mechanical angular velocity ωm. The assumption of the loss torque is that at a constant rotation speed and with no external torque applied, motor torque Tm - loss torque = 0, that is,

number

[0044] First, the rotation speed was changed and the average value of the motor terminal current im was measured while changing the input voltage Vin at each rotation speed. The measurement results are shown in the upper left of Figure 8. Using the average value of the motor terminal current and the back electromotive force constant Ke (= torque constant Kt) shown in Figure 7 above, the motor torque Tm was calculated from equation (2) above. As shown in Figure 8, the motor torque Tm can be obtained for each rotation speed. Because the motor torque Tm and loss torque balance out during constant speed rotation, the plot of motor torque Tm shown in Figure 8 can be considered a plot of loss torque. Because the coefficient of determination is good when the plot shown in Figure 8 is regressed using a quadratic equation, the loss torque was treated as a quadratic equation of the mechanical angle velocity ωm, as described above.

[0045] <<About the winding circuit>> The winding circuit section 2111B is a model that faithfully models the geometric arrangement of the windings WR, permanent magnets Mg, brushes BR, and commutator segments CM in the motor 20. FIG. 9 shows model parameters in the motor physical model 211. Details of the winding circuit section 2111B will be described below using the parameters in the winding circuit section 2111B shown in FIG. 9. Note that FIG. 9 also shows the above-mentioned parameters in the equation of motion section 2111A, as well as the input variables and internal variables in the motor physical model 211. Although the external torque Tex is treated as a parameter, it may also be treated as an input variable.

[0046] The number of pole pairs p is the number of pairs of magnetic poles formed by the permanent magnet Mg. In the configuration of Figure 5 (Figure 4), there are two pairs of north and south poles, so the number of pole pairs p = 2. The total number of windings Ncoil is the total number of windings WR. In the configuration of Figure 5, the total number of windings Ncoil = 16.

[0047] The inductance L_1 per winding WR and the resistance R_1 per winding WR can be set by measuring, for example, two parallel circuits of eight windings in series at the midpoints of the loop circuit formed by the winding WR, which are 180 degrees symmetrical, in the configuration of Figure 5, and calculating the average value per winding.

[0048] In reality, there is a gap between adjacent commutator bars CM. As shown in Figure 10, the gap between the commutator bars CM is highlighted, and the commutator bar gap (gap) is set as the distance of the gap. The commutator bar gap (gap) is set in units of the ripple angle θm (described below) [rad]. The commutator bar gap (gap) is set based on the observation results of an actual machine.

[0049] Brush resistance R_B is the contact resistance value when the brush BR and commutator segments CM are in contact so that their widths exactly overlap, as shown in the upper part of Figure 11. Figure 11 shows an example in which the brush BR and commutator segments CM7 are in contact. In this case, the contact resistance between the commutator segments CM and the brush BR is at its smallest. Brush resistance R_B is adjusted so that the waveform (ripple waveform) of the motor terminal current im matches that of the actual machine and the model.

[0050] When the contact width between the brush BR and the commutator segments CM is very small, the ultimate contact resistance becomes infinite. The bottom part of Figure 11 shows an example of a state where the contact width between the brush BR and the commutator segments CM7 is very small. However, calculations that include infinity are difficult to perform in simulations, and it is believed that such an extreme state does not actually occur. Therefore, a saturation value Sat is set as the upper limit of the contact resistance to prevent division by zero. The saturation value Sat is adjusted so that the waveform (ripple waveform) of the motor terminal current im matches the actual machine and the model.

[0051] 12 is a plan cross-sectional view that schematically shows the movement of side WR1_H of the winding WR1 around the rotation axis J and the magnetic flux density B due to the permanent magnet MgN1 (with north pole on the radially inner side) when focusing on side WR1_H. Side WR1_H is a side of the winding WR1 that extends in the axial direction at the end of the winding WR1 on the opposite side of the rotation direction θrt. As shown in FIG. 12, the state in which side WR1_H is located on the line connecting the end of the permanent magnet MgN1 on the opposite side of the rotation direction θrt to the rotation axis J is defined as mechanical angle θm=0, and the magnetic flux density B due to the magnetic flux passing through side WR1_H is determined according to the mechanical angle θm.

[0052] Therefore, as shown in FIG. 13, the magnetic flux density distribution is set by setting the magnetic flux density B as a function B(θm) of the mechanical angle θm. In this case, the maximum magnetic flux density Bm is set as a parameter, and B = +Bm in the range where the north pole is located radially inward, and B = -Bm in the range where the south pole is located radially inward. Note that the polarity of the magnetic flux density B is positive in the direction toward the rotation axis J, as shown in FIG. 12. In the range between the north and south poles, the magnetic flux density B is set to vary between +Bm and -Bm. In FIG. 13, B is set to vary linearly between +Bm and -Bm, but the method of variation is not limited to this. The magnetic flux density distribution can be set using the maximum magnetic flux density Bm and a formula block. Note that the relative positions of the windings WR2 to WR16 with respect to the winding WR1 are determined, and therefore the magnetic flux density distribution for each side corresponding to the side WR1_H is determined according to the mechanical angle θm.

[0053] The positional deviation Sgap (unit: [rad]) is a parameter that represents the positional relationship between the magnetic poles of the permanent magnet Mg and the brush BR. In the example shown in FIG. 14, the positional deviation Sgap is defined when the brush BR deviates from the reference positional relationship between the magnetic poles of the permanent magnet Mg and the brush BR shown at the top (similar to FIG. 13) to the state shown at the bottom. The positional deviation Sgap is handled in the model so that the reference position (origin) of the magnetic flux density distribution can be changed depending on the positional deviation Sgap. This is because even if the mechanical angle θm is the same, that is, the position of the commutator segments CM relative to the brush BR is the same, if a positional deviation Sgap occurs, the magnetic flux density relative to the winding WR will change. The positional deviation Sgap is set based on the results of observations of an actual machine.

[0054] The winding side length l is a parameter that represents the length of the side of the winding WR that extends in the axial direction at the end of the direction of rotation θrt, as shown in Fig. 15. In the case of the winding WR1, the winding side length l corresponds to the length of the side WR1_H described above. The length l is set based on the observation results of an actual device.

[0055] The distance r from the axis of rotation to the side of the winding is a parameter that represents the radial distance from the axis of rotation J to the side WR_H. Figure 16 (similar to Figure 12) shows the distance r of the winding WR1 relative to the side WR1_H as an example. The distance r is set based on the observation results of an actual device.

[0056] Figure 17 is a diagram showing the circuit configuration around the motor terminals (also shown in Figure 5, etc.). A capacitor C0 is connected between the motor positive terminal Tp and the motor negative terminal Tn. An inductor L0 is connected to the motor positive terminal Tp and the motor negative terminal Tn, respectively. One end of one inductor L0 is connected to the motor positive terminal Tp, and the other end is connected to the positive brushes BR_P1 and BR_P2. One end of the other inductor L0 is connected to the motor negative terminal Tn, and the other end is connected to the negative brushes BR_N1 and BR_N2. Capacitor C0 and inductor L0 form an LC filter. The LC filter is used to suppress pulse-like noise that occurs when the commutator segments CM and brushes BR are switched. The capacitance value of capacitor C0 and the inductance value of inductor L0 are each set as parameters.

[0057] Next, we will discuss the induced electromotive force generated in the winding WR. When each of the windings WR1 to WR16 crosses the magnetic flux generated by the permanent magnet Mg, an induced electromotive force is generated in each of the windings WR1 to WR16. As mentioned above, the magnetic flux density distribution B is set as a function of the mechanical angle θm. Using this set magnetic flux density distribution, the induced electromotive force is calculated from the time change in the magnetic flux linking each of the windings WR1 to WR16.

[0058] 18 is a schematic plan view, a perspective view, and a development view showing a state in which one winding WR is moved by the rotation of the rotor 20B. It is assumed that the winding WR moves from a state represented by ABCD to a state represented by A' B' C' D'.

[0059] Referring to the development diagram shown in FIG. 19, the area DCC'D' swept by the front side CD relative to the rotation direction θrt is the area increased by the rotation of the winding WR, and is expressed as a positive area. On the other hand, the area ABB'A' swept by the rear side BA relative to the rotation direction θrt is the area decreased by the rotation of the winding WR, and is expressed as a negative area. Furthermore, the area A'B'CD is the area that remains unchanged before and after the rotation, and the magnetic flux that penetrates this area also remains unchanged, so it does not contribute to the magnetic flux change Δφ. From the above, the magnetic flux change Δφ is calculated as the product of the signed area and the magnetic flux density that passes through that area. Therefore, the induced electromotive force e coil,No. is expressed by the following equation: e coil,No. =Δφ / Δt=((magnetic flux density at the position of the front edge) × (scanning area of ​​the front edge) + (magnetic flux density at the position of the rear edge) × (- (scanning area of ​​the rear edge))) / Δt

[0060] In addition, e coil,No. is the induced voltage generated in the winding represented by No. (winding number) (for example, WR1 if No.=1).

[0061] Additionally, using the length of the winding side, l, and the distance of the winding side from the axis of rotation, r, the above positive area can be calculated as l·rωm, and the negative area as -l·rωm.

[0062] 20 is a diagram showing an overall view of the winding circuit section 2111B. coil,No. was modeled so that it was output from a voltage source inserted in series with the inductance L_1 and the resistance R_1 in each of the windings WR1 to WR16.

[0063] Next, the ripple angle θr shown in Fig. 20 will be explained. If the brush BR of interest is referred to as a predetermined brush (positive brush BR_P1 in Fig. 20) and the commutator segment CM of interest is referred to as a predetermined commutator segment (commutator segment CM2 in Fig. 20), the contact resistance Rc between the predetermined brush and the predetermined commutator segment can be found as follows:

[0064] The commutator segment CM adjacent to the specified commutator segment on the rotational direction θrt side is called the front commutator segment (commutator segment CM1 in Figure 20), and the adjacent commutator segment CM on the opposite side of the rotational direction θrt of the specified commutator segment is called the rear commutator segment (commutator segment CM3 in Figure 20).When the rear end of the specified brush coincides with the rear end of the front commutator segment (when the width of the specified brush and the width of the front commutator segment exactly coincide), the ripple angle θr = 0, and the distance from the rear end of the specified brush to the rear end of the front commutator segment is expressed as ripple angle θr [rad]. When the rear end of a given brush coincides with the rear end of a given commutator segment (when the width of the given brush and the width of the given commutator segment exactly match), the ripple angle θr = 2π, and when the rear end of a given brush coincides with the rear end of a rear commutator segment (when the width of the given brush and the width of the rear commutator segment exactly match), the ripple angle θr = 4π. The ripple angle θr can be converted from the mechanical angle θm.

[0065] Based on the ripple angle θr, the contact resistance Rc between a given brush and a given commutator segment can be calculated as shown in the table in Figure 21. B corresponds to the brush resistance R_B. The contact resistance value is ∞ outside the range of the ripple angle θr shown in Figure 21. However, as mentioned above, if the calculated contact resistance Rc exceeds the saturation value Sat, the contact resistance Rc = Sat.

[0066] FIG. 22 is a diagram showing the configuration of a motor physical model 211 when modeling is performed using Simscape (registered trademark) / Simulink (registered trademark).

[0067] Equation of motion section 2111A receives motor terminal current im output from winding circuit section 2111B, and outputs mechanical angle θm and mechanical angle angular velocity ωm, which are fed back to winding circuit section 2111B.

[0068] The winding circuit section 2111B has an induced voltage generating section 2A, a winding circuit model section 2B, a ripple angle converting section 2C, a contact resistance value generating section 2D, and a switching signal generating section 2E.

[0069] The induced voltage generating unit 2A generates an induced voltage for each winding WR based on the mechanical angle θm. FIG. 23 shows a partial configuration of an example of the winding circuit model unit 2B. Here, considering the number of pole pairs p=2, modeling is performed for eight windings WR, which is half of the total number of 16 windings WR. Note that modeling may also be performed for the entire actual number of windings WR.

[0070] Therefore, as shown in Fig. 23, the winding WR is modeled by WR1 to WR8, and the brush BR is modeled by a pair of a positive brush and a negative brush. coil,No. is output from the voltage source E inserted in the winding WR of the corresponding winding number. In Figure 23, the induced voltage e coil,8 is shown output from voltage source E8 at winding WR8.

[0071] 23, the winding circuit model unit 2B is modeled so that switches SW1 and SW2 and variable resistors VR1 and VR2 are provided for each winding WR. Specifically, in the winding WR, an inductor L_1 and a resistor R_1 are connected in series, with one end of the resistor R_1 (the end opposite to the end connected to the inductor L_1) connected to one end of the variable resistor VR1, and a switch SW1 connected between the other end of the variable resistor VR1 and a positive line LP. The positive line LP is connected to a positive brush. One end of the resistor R_1 is also connected to one end of the variable resistor VR2, and a switch SW2 is connected between the other end of the variable resistor VR2 and a negative line LN. The negative line LN is connected to the negative brush.

[0072] When the commutator segment CM, to which the lead wire of the winding WR is connected, comes into contact with the positive brush, switch SW1 is turned on, and the resistance value of variable resistor VR1 is set to the contact resistance value. When the commutator segment CM, to which the lead wire of the winding WR is connected, comes into contact with the negative brush, switch SW2 is turned on, and the resistance value of variable resistor VR2 is set to the contact resistance value. When the commutator segment CM and the positive or negative brush are not in contact, switch SW1 or SW2 is turned off. There are cases where both switches SW1 and SW2 are turned off.

[0073] The switching signal generation unit 2E shown in FIG. 22 determines whether to turn on or off the switches SW1 and SW2 for each winding WR based on the mechanical angle θm, and generates a switching signal. The switches SW1 and SW2 are turned on or off based on the generated switching signal. The ripple angle conversion unit 2C converts the mechanical angle θm into a ripple angle θr. The contact resistance value generation unit 2D generates a contact resistance value between the commutator segments CM and the brush BR based on the ripple angle θr. The generated contact resistance value is set as the resistance value of the variable resistors VR1 and VR2.

[0074] The winding circuit model unit 2B calculates and outputs the motor terminal current im when an input voltage Vin is input, with the induced voltage by the voltage source E, the on / off states of the switches SW1 and SW2, and the resistance values ​​of the variable resistors VR1 and VR2 being determined. Note that when modeling is performed with eight windings WR, taking into account the number of pole pairs = 2 as described above, the motor terminal current im is halved, so the calculated motor terminal current im is input to an amplifier with a gain = 2 and output to the equation of motion unit 2111A.

[0075] <Simulation results> FIG. 24 is a diagram showing an example of the results of a simulation according to the present disclosure. In response to application of input voltage Vin, a ripple waveform occurs in the motor terminal current im, similar to that of an actual machine. FIG. 25 is a diagram showing an example of a comparison between the relationship between input voltage Vin and mechanical angular rotation speed in an actual machine and in a simulation. In this way, the simulation reproduces a phenomenon similar to that of an actual machine, in which the mechanical angular rotation speed increases as the input voltage Vin increases. The simulation according to the present disclosure can significantly reduce the amount of calculation and shorten the simulation time.

[0076] <Other> In addition to the above-described embodiments, various modifications can be made to the various technical features disclosed in this specification without departing from the spirit of the technical creation. In other words, the above-described embodiments should be considered to be illustrative and not restrictive in all respects, and the technical scope of the present disclosure should not be limited to the above-described embodiments, but should be understood to include all modifications that fall within the meaning and scope equivalent to the claims.

[0077] <Additional Notes> As described above, the simulation device (1) according to one aspect of the present disclosure: a model storage unit (2) in which a motor physical model (211) modeling a brushed motor (20) is stored; a model calculation unit (3) configured to perform calculation processing using the motor physical model; Equipped with The motor physical model is configured to have a winding circuit section (2111B) that models the permanent magnets (Mg), windings (WR), commutator segments (CM) connected to the windings, and brushes (BR) configured to be able to come into contact with the commutator segments in the brushed motor (first configuration).

[0078] In addition, in the first configuration, the winding circuit unit may be configured to be able to input a mechanical angle (θm) of a rotor (20B) including the windings and the commutator segments, and to be able to reproduce successive changes in the contact state between the commutator segments and the brushes according to the mechanical angle (second configuration).

[0079] In addition, in the above second configuration, the winding circuit unit may be configured to have a contact resistance value generating unit (2D) configured to calculate the contact resistance value (Rc) between the commutator segments and the brush based on the mechanical angle (third configuration).

[0080] In the third configuration, the winding circuit unit includes a conversion unit (2C) configured to convert angle information (θr) representing the relative position of the commutator segments with respect to the brushes from the mechanical angle, The contact resistance value generating unit may be configured to calculate the contact resistance value based on the angle information (fourth configuration).

[0081] Furthermore, in the above fourth configuration, the contact resistance value generating unit may be configured to calculate the contact resistance value based on the contact resistance value (R_B) when the widths of the commutator segments and the brush are exactly the same, the gap distance (gap) between adjacent commutator segments, and the angle information (fifth configuration).

[0082] In addition, in the fifth configuration, an upper limit value (Sat) for limiting the calculated contact resistance value may be set (sixth configuration).

[0083] In addition, in any one of the third to sixth configurations, the winding circuit section a first variable resistor (VR1) and the first switch (SW1) connected between the winding and the positive brush; a second variable resistor (VR2) and the second switch (SW2) connected between the winding and the negative brush; a switching signal generating unit (2E) configured to generate a switching signal for switching on and off the first switch and the second switch based on the mechanical angle; and The contact resistance value generated by the contact resistance value generating unit may be set as the resistance value of each of the first variable resistor and the second variable resistor (seventh configuration).

[0084] Furthermore, in any of the first to seventh configurations, the winding circuit unit may have an induced electromotive force generating unit (2A) configured to calculate an induced electromotive force generated in the winding based on the mechanical angle and mechanical angle angular velocity (ωm) of a rotor including the winding and the commutator segments (eighth configuration).

[0085] In addition, in the eighth configuration, the winding circuit section may be configured so that a voltage source (E) inserted in series with the inductor (L_1) and resistor (R_1) of the winding outputs the induced voltage (ninth configuration).

[0086] In the eighth or ninth configuration, a magnetic flux density distribution (B) by the permanent magnet with respect to the mechanical angle can be set, The induced voltage generating unit may be configured to calculate the induced voltage based on the magnetic flux density distribution (tenth configuration).

[0087] In addition, in the above-mentioned tenth configuration, the magnetic flux density distribution may be set by setting the maximum magnetic flux density (Bm) corresponding to the north and south poles and setting the way in which the magnetic flux density changes between the north and south poles (eleventh configuration).

[0088] In the tenth or eleventh configuration, a gap (Sgap) in the relative positional relationship between the permanent magnet and the brush can be set, The reference position of the magnetic flux density distribution may be changed in accordance with the deviation (twelfth configuration).

[0089] In addition, in any one of the first to twelfth configurations, the winding circuit section A capacitor (C0) connected between the motor positive terminal (Tp) and the motor negative terminal (Tn); The modeling may also include an inductor (L0) connected between the positive terminal of the motor and the positive brush, and between the negative terminal of the motor and the negative brush (13th configuration).

[0090] In addition, in any one of the first to thirteenth configurations, the motor physical model has a rotational motion equation part (2111A), The winding circuit unit may receive an input voltage (Vin) applied between motor terminals, a mechanical angle of a rotor including the windings and the commutator segments, and a mechanical angle and angular velocity of the rotor; the winding circuit unit is capable of outputting a motor terminal current (im) flowing through the motor terminal, the equation of motion unit is capable of calculating a motor torque (Tm) based on the motor terminal current, and is capable of calculating the mechanical angle angular velocity and the mechanical angle based on the motor torque; The mechanical angle and the mechanical angle angular velocity output from the equation of motion unit may be fed back to the winding circuit unit (fourteenth configuration).

[0091] Furthermore, a program according to an aspect of the present disclosure is a program for causing a computer to function as the simulation device of any one of the first to fourteenth configurations (fifteenth configuration).

[0092] In addition, a simulation method according to one embodiment of the present disclosure is a simulation method in which a computer performs calculations using a motor physical model having a winding circuit section that models permanent magnets, windings, commutator segments connected to the windings, and brushes configured to be able to come into contact with the commutator segments in a brushed motor (16th configuration). [Industrial Applicability]

[0093] The present disclosure can be used to simulate a BDC motor. [Explanation of symbols]

[0094] 1 Simulation device 2 Model storage section 2A induced electromotive force generation section 2B Winding circuit model 2C Ripple angle conversion part 2D contact resistance value generator 2E Switching signal generator 3 Model calculation section 4. Model setting section 5 Display control section 6 Operation input section 7 Display section 20 Motor 20A housing 20B rotor 20C axis 20D Stator 20E bearing 100 computers 100A CPU 100B memory 100C auxiliary storage 100D Operation input section 100E Display section 201 units 202 Iron Core 202A Annular section 202B Teeth 211 Motor Physical Model 2111A Motion equation part 2111B Winding circuit section BR_P1, BR_P2 positive brush BR_N1, BR_N2 negative brushes BR Brush C0 capacitor CM commutator piece CM1~CM16 Commutator piece E voltage source E8 voltage source J rotation axis L0 inductor LN negative electrode line LP positive line Mg permanent magnet MgN1, MgN2, MgS1, MgS2 permanent magnets P Program SW1 and SW2 switches Tn Motor negative terminal Tp Motor positive terminal VR1, VR2 variable resistors WR winding WR1~WR16 windings

Claims

1. a model storage unit in which a motor physical model that models a brushed motor is stored; a model calculation unit configured to perform calculation processing using the motor physical model; Equipped with The motor physical model is a simulation device having a winding circuit section that models the permanent magnets, windings, commutator segments connected to the windings, and brushes configured to be able to come into contact with the commutator segments in the brushed motor.

2. 2. The simulation device according to claim 1, wherein the winding circuit unit is capable of inputting a mechanical angle of a rotor including the windings and the commutator segments, and is capable of reproducing successive changes in the contact state between the commutator segments and the brushes according to the mechanical angle.

3. 3. The simulation device according to claim 2, wherein the winding circuit unit includes a contact resistance value generating unit configured to calculate a contact resistance value between the commutator segments and the brushes based on the mechanical angle.

4. the winding circuit unit has a conversion unit configured to convert the mechanical angle into angle information representing the relative position of the commutator segments with respect to the brush, The simulation device according to claim 3 , wherein the contact resistance value generating unit calculates the contact resistance value based on the angle information.

5. 5. The simulation device according to claim 4, wherein the contact resistance value generating unit calculates the contact resistance value based on the contact resistance value when the widths of the commutator segments and the brushes exactly match, the distance between the gaps between adjacent commutator segments, and the angle information.

6. The simulation device according to claim 5 , wherein an upper limit value for limiting the calculated contact resistance value can be set.

7. The winding circuit section includes: a first variable resistor and the first switch connected between the winding and the positive brush; a second variable resistor and the second switch connected between the winding and the negative brush; a switching signal generating unit configured to generate a switching signal for switching on and off the first switch and the second switch based on the mechanical angle; and The simulation device according to claim 3 , wherein the contact resistance value generated by the contact resistance value generating unit is set to a resistance value of each of the first variable resistor and the second variable resistor.

8. 2. The simulation device according to claim 1, wherein the winding circuit unit includes an induced electromotive force generating unit configured to calculate an induced electromotive force generated in the winding based on a mechanical angle and a mechanical angle angular velocity of a rotor including the winding and the commutator segments.

9. 9. The simulation device according to claim 8, wherein the winding circuit section is modeled as a voltage source inserted in series with an inductor and a resistor of the winding, and outputs the induced voltage.

10. A magnetic flux density distribution by the permanent magnet with respect to the mechanical angle can be set, The simulation device according to claim 8 , wherein the induced voltage generating unit calculates the induced voltage based on the magnetic flux density distribution.

11. 11. The simulation device according to claim 10, wherein the magnetic flux density distribution is set by setting maximum magnetic flux densities corresponding to the north and south poles and setting a manner in which the magnetic flux density varies between the north and south poles.

12. A deviation in the relative positional relationship between the permanent magnet and the brush can be set, The simulation device according to claim 10 , wherein the reference position of the magnetic flux density distribution is changed in accordance with the deviation.

13. The winding circuit section includes: a capacitor connected between the positive terminal of the motor and the negative terminal of the motor; 2. The simulation device according to claim 1, wherein the model also includes inductors connected between the positive terminal of the motor and the positive brush and between the negative terminal of the motor and the negative brush.

14. the motor physical model has a rotational motion equation part, The winding circuit unit can receive an input voltage applied between motor terminals, a mechanical angle of a rotor including the windings and the commutator segments, and a mechanical angle and angular velocity of the rotor, the winding circuit unit is capable of outputting a motor terminal current flowing through the motor terminal; the equation of motion unit is capable of calculating a motor torque based on the motor terminal current, and is capable of calculating the mechanical angle velocity and the mechanical angle based on the motor torque; The simulation device according to claim 1 , wherein the mechanical angle and the mechanical angle angular velocity output from the equation of motion unit are fed back to the winding circuit unit.

15. A program for causing a computer to function as the simulation device according to any one of claims 1 to 14.

16. A simulation method in which a computer performs calculations using a motor physical model having a winding circuit section that models permanent magnets, windings, commutator segments connected to the windings, and brushes configured to be able to come into contact with the commutator segments in a brushed motor.

Images