JP2007030664A - Electromagnetic suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic suspension device capable of efficiently carrying out energy regeneration by a motor, and improving charging efficiency of a power supply. <P>SOLUTION: The electromagnetic suspension device is provided with a first member, a second member showing relative movement to the first member, and the motor M capable of at least suppressing the relative movement. When a necessary load to be output is lower than the most efficiently charging load wherein the charging efficiency of the power supply E by generation of the motor M becomes maximum to stroke speed, a d-phase current is controlled to be higher efficiency that the charging efficiency at the time of generation of the necessary load while generating the necessary load, thereby carrying out efficient charging control. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of an electromagnetic suspension device that is optimal for a vehicle.

  As this type of electromagnetic suspension device, for example, a cylinder connected to one of the sprung member or unsprung member of the vehicle, a rod connected to one of the sprung member or unsprung member and inserted into the cylinder, A linear motor is composed of a plurality of permanent magnets mounted on the outer periphery of the rod in an axial direction and a plurality of windings provided on the inner periphery of the cylinder and facing the permanent magnet, and the electromagnetic force of the linear motor is It is used as a load (control force) that suppresses relative movement in the axial direction with the cylinder.

And the winding in this linear motor is made into three phases of U, V, and W, and the electromagnetic suspension device constituted as a linear motor is PWM (Pulse Width Modulation) controlled by an inverter, and the generated damping force is made variable. In this electromagnetic suspension device, since the load generation source is a linear motor, energy regeneration for converting the kinetic energy in the relative movement between the rod and the cylinder into electric energy is performed. Is possible.
Japanese Patent Laying-Open No. 2003-104025 (Detailed Description of the Invention, FIG. 15)

  As described above, since the above-described electromagnetic suspension device can perform energy regeneration, it can be charged to a battery as a power source when mounted on a vehicle, and a load is applied according to the vehicle speed. Although it is useful in that it is intended to save power by effectively using the current generated by the motor by limiting the area where it occurs, it may be pointed out that there are the following problems .

  That is, the regenerative region where energy regeneration can be completely performed in the conventional electromagnetic suspension device is a limited range, and depending on the above-described control, it is not always possible to generate a load in the regenerative region where the battery can be charged. It may not necessarily lead to power saving.

  Therefore, in the conventional electromagnetic suspension device, although the above-described power saving is achieved, there are cases where the power supply cannot be sufficiently charged because of insufficient charging efficiency.

  In recent years, the development of hybrid vehicles equipped with motors and gasoline engines to improve fuel consumption and electric vehicles that are driven entirely by motors has become active, and such power consumption becomes intense. However, since the power consumption of the electromagnetic suspension device may affect the driving of the vehicle, the conventional electromagnetic suspension device may not be sufficient in terms of power consumption.

  Therefore, the present invention was devised in order to improve the above-described problems, and an object of the present invention is to provide an electromagnetic suspension device that can improve the efficiency of energy regeneration by the motor and increase the charging efficiency of the power source. Is to provide.

  In order to achieve the above object, in an electromagnetic suspension device including one member, the other member exhibiting relative motion with respect to the one member, and a motor capable of at least suppressing the relative motion, the motor generates power with respect to the stroke speed. When the required load to be output is lower than the most efficient charging load, which is the load that maximizes the charging efficiency of the power supply, the d-phase current is set to be higher than the charging efficiency when the required load is generated while generating the required load. Controlled to perform efficient charging control.

  According to the electromagnetic suspension device of the present invention, this efficient charging control can increase the regenerative current while generating a load necessary for performing vehicle body posture control. It becomes possible to improve the charging efficiency.

  And in order to charge the power source efficiently, there is no influence on the load required for the vehicle body posture control, so the control of the vehicle body posture can be switched without sacrificing the ride comfort in the vehicle. Therefore, it is possible to prevent the vehicle occupant from feeling uncomfortable or uneasy by, for example, sensing vibrations that occur when the control is switched.

  In addition, this electromagnetic suspension device can be efficiently charged with a power source, so that it is possible to reliably achieve power saving, and a hybrid vehicle equipped with a motor and a gasoline engine to improve fuel efficiency. It is most suitable for an electric vehicle that is driven entirely by a motor. In particular, when the power source is a vehicle battery, if the voltage of the power source E decreases, a vehicle that uses a motor such as a hybrid vehicle as a driving source. Then, although it will affect driving performance, according to this electromagnetic suspension device, since the power source can be charged efficiently, the driving performance of such a vehicle can be improved.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a conceptual diagram of an electromagnetic suspension device according to an embodiment. FIG. 2 is a system diagram of a control unit in the electromagnetic suspension device. FIG. 3 is a diagram illustrating the PWM circuit. FIG. 4 is a diagram illustrating a regeneration region. FIG. 5 is a diagram illustrating a setting frequency state of generated loads on the expansion side and the contraction side of a shock absorber applied to light, small, and ordinary automobiles. FIG. 6 is a diagram showing the frequency of the expansion / contraction stroke speed of the shock absorber while the vehicle is running. FIG. 7 is a diagram showing a stroke load-load characteristic capable of charging the power supply most efficiently. FIG. 8 is a diagram illustrating the relationship between the regenerative current and the load at an arbitrary stroke speed. FIG. 9 is a diagram showing a region where the efficiency charging control is performed in relation to the stroke speed and the load. FIG. 10 is a diagram illustrating a region in which efficient charging control is performed in relation to the stroke speed and the q-phase current. FIG. 11 is a diagram illustrating the relationship between the stroke speed and the combined vector of the d-phase current and the q-phase current that maximize the regenerative current. FIG. 12 is a diagram illustrating the relationship between the first gain and the stroke speed. FIG. 13 is a diagram illustrating a relationship between the second gain and the q-phase current target value. FIG. 14 is a diagram showing a controllable region of the electromagnetic suspension device. FIG. 15 is a conceptual diagram of another electromagnetic suspension device.

  As shown in FIG. 1, the electromagnetic suspension device in one embodiment is connected to a screw shaft 1 that is one member, a ball screw nut 2 that exhibits relative motion with respect to the screw shaft 1, a motor M, and a motor M. And a control unit 20.

  Specifically, the screw shaft 1 is rotatably engaged with the ball screw nut 2, and the upper end of the screw shaft 1 in FIG. 1 is connected to the rotor R of the motor M. The other ball screw nut 2 is fixed to the upper end of a cylinder 4 into which the screw shaft 1 is inserted, and can be connected to one of the sprung member and the unsprung member of the vehicle via this cylinder 4. It is like that.

  The screw shaft 1 is rotatably connected to the other of the sprung member and the unsprung member of the vehicle. Specifically, the screw shaft 1 is provided on the other of the sprung member and the unsprung member of the vehicle. The motor M is fixed to the other of the sprung member and the unsprung member of the vehicle.

  Therefore, when the screw shaft 1 and the ball screw nut 2 exhibit a linear relative motion in the axial direction, the screw shaft 1 exhibits a rotational motion, and the rotational motion of the screw shaft 1 is transmitted to the rotor R of the motor M. It will be. Here, the rotational speed of the screw shaft 1 may be reduced through a reduction gear constituted by a gear mechanism or the like to transmit the rotational motion of the screw shaft 1 to the rotor R.

  When the screw shaft 1 and the ball screw nut 2 exhibit a linear relative motion in the axial direction, the ball screw nut 2 is used when the screw shaft 1 cannot be rotated and the ball screw nut 2 is rotated instead. The rotational motion of 2 may be transmitted to the rotor R of the motor M. Specifically, the screw shaft 1 is non-rotatably connected to one of the sprung member and unsprung member of the vehicle, and the other ball screw nut 2 is connected to the other of the sprung member and unsprung member of the vehicle with a ball bearing or the like. And the rotational movement of the ball screw nut 2 may be transmitted to the rotor R of the motor M via a gear mechanism, a friction wheel mechanism, or the like.

  In this case, the motor M includes a cylindrical frame 10, a stator that is an armature provided on the inner peripheral side of the frame 10, and a rotor R that is rotatably supported by the frame 10. Specifically, the stator includes an annular stator core 11 having a plurality of teeth, and a winding 12 in each of the U, V, and W phases wound around each tooth, The rotor R includes a shaft 13 and a driving magnet 14 mounted on the outer periphery of the intermediate portion of the shaft 13.

  The drive magnet 14 is composed of a block magnet that can realize a predetermined number of poles and is embedded in the shaft 13, and the motor M is an embedded magnet type. Of course, the drive magnet 14 is blocked so that a predetermined number of poles can be realized and bonded to the outer periphery of the shaft 13, or it is formed in an annular shape and dividedly magnetized so as to be fitted to the outer periphery of the shaft 13. However, when the so-called surface magnet type is used, an eddy current loss is likely to occur on the surface of the driving magnet 14 during field weakening control, which will be described later, and therefore the embedded magnet type is preferable.

  The motor M is equipped with a rotation angle sensor 15 for detecting the rotation angle of the rotor R. Specifically, for example, the rotation angle sensor 15 is attached to the resolver core provided on the shaft 13 and the frame 10. It only has to be constituted by a resolver stator facing the provided resolver core. In addition, an optical encoder may be adopted, and when a sensing magnet is provided in the rotor R, a Hall element, MR element, etc. The magnetic sensor may be provided on the frame 10.

  As described above, in this electromagnetic suspension device, since the drive source is the motor M, when the motor M is driven by being supplied with electric energy, the screw shaft 1 is rotationally driven to rotate the screw shaft 1 and the ball. The screw nut 2 can be positively moved in a relatively linear motion, that is, can be stroked, and the function as an actuator can be exhibited.

  In addition, when a rotational motion is forcibly input from the screw shaft 1, the motor M generates a magnetic field by generating a magnetic field due to an induced electromotive force or power from the power source, thereby generating an electromagnetic force. Since the torque that suppresses the rotational movement of the shaft 1 is generated, it functions to suppress the relative linear movement of the screw shaft 1 and the ball screw nut 2. That is, in this case, the torque generated by the electric power obtained by the motor M regenerating kinetic energy input from the outside and converting it into electric energy, or by the electric power supplied from the power source in addition to this regeneration. Thus, the relative linear motion of the screw shaft 1 and the ball screw nut 2 can be suppressed.

  Therefore, this electromagnetic suspension device can cause the motor M to function as both an actuator and a generator, so that the relative linear motion of the screw shaft 1 and the ball screw nut 2 can be suppressed, and at the same time, the function as an actuator can be utilized. Thus, the posture control of the vehicle body of the vehicle can be performed at the same time, so that the function as an active suspension can be exhibited.

  In order to control the current flowing through the winding 12 of the motor M, specifically, the U, V, and W phase windings 12 are connected to the control unit 20, and the motor M is connected to the control unit 20. Is driven and controlled.

  As shown in FIG. 2, the control unit 20 basically performs dq conversion on the current flowing in two phases of the three phases of the winding 12 to calculate a d-phase current value and a q-phase current value. Proportion for calculating the d-phase voltage command value and the q-phase voltage command value based on each current target value determined by the phase current calculation means 21 and the current target value calculation unit 26 and the d-phase and q-phase current values. The integration control unit 22, the three-phase conversion calculation means 23 for converting the d-phase voltage command value and the q-phase voltage command value into voltage command values for U, V, and W phases, and U, V of the three-phase brushless motor. , W, a current detector 24 for detecting a current value flowing in two phases, a PWM circuit 25 as a motor drive circuit, and a limiter 28 are provided.

  The control unit 20 includes the d-phase and q-phase current target values determined by the current target value calculation unit 26, and the d-phase and q-phase current values obtained as the calculation results of the two-phase current calculation means 21. The motor M is proportional-integral controlled based on the respective deviations. Note that proportional differential integration control may be performed by adding an element obtained by differentiating the deviation.

  Here, the current target value calculation unit 26 outputs the d-phase and q-phase current target values to the proportional integral control unit 22 as a torque command. The electromagnetic suspension device follows the vehicle body posture in accordance with a predetermined control law. The vehicle speed, the steering angle, and the spring, which are information necessary for controlling the load generated in the vehicle, and for efficiently charging the power source E (described later) by energy regeneration of the motor M (described later) and field weakening control. The upper and unsprung speed / acceleration, stroke speed, and the like are input to the current target value calculation unit 26 as voltage signals and the like from various sensors provided in the vehicle as appropriate in addition to the rotation angle sensor 15.

  The expansion / contraction amount, stroke speed and expansion / contraction acceleration of the electromagnetic suspension device may be calculated from the rotation angle θ obtained from the rotation angle sensor 15, the pitch of the screw shaft 1, and the reduction ratio, and there is no need to provide a separate sensor. .

  For example, when the skyhook theory is adopted as the control law of the vehicle body posture control, the sprung speed in the vehicle may be input to the current target value calculation unit 26. In this case, The current target value calculation unit 26 calculates the d-phase current target value and the q-phase current target value as a torque command from the sprung speed, and outputs them to the proportional integration control unit 22.

  The current value target calculation unit 26 basically applies not only the control law of the vehicle body attitude control to the d-phase current target value in a state where the efficiency charging control and field weakening control described later are applied. When the calculation is based on the efficiency charging control and the field weakening control and only the vehicle body posture control is performed in a state where the efficiency charging control and the field weakening control are not applied, the d-phase current is generated by the motor M. Since it does not contribute to torque, the load generated by the electromagnetic suspension device depends on the q-phase current, so that the d-phase current target value is output as zero.

  Further, as the current detector 24, a non-contact type using a Hall element, a winding, or the like, or a current sensor that obtains a current value from a voltage drop of a resistor connected in series to each of the three-phase windings 12 is used. Good.

  The current detector 24 only needs to detect the current value flowing in two phases of the U, V, and W phases. This is described below from the electrical angle θ of the rotor R if the current values of the two phases are known. This is because it can be converted into d-phase and q-phase current values using the equation (1).

  Further, as shown in FIG. 3, the PWM circuit 25 includes a power supply E, six switching elements 41 that supply current to the windings 12 of the three phases of the motor M, and PWM pulse signals to the switching elements 41. The PWM circuit 25 includes a pulse generator (not shown) such as a multivibrator to be provided, and the PWM circuit 25 is configured to adjust the phase to each phase with a predetermined PWM duty ratio based on each voltage command value output from the proportional integration control unit 21. Supply current. The power supply E may be a battery mounted on the vehicle.

比例積分制御部２２は、各電流目標値ｉｄ*，ｉｑ*と電流値ｉｄ，ｉｑの各偏差εｄ，εｑを算出し、算出された偏差εｄ，εｑを積分して得られた積分値に所定の積分ゲインを乗じ、さらには、各偏差εｄ，εｑに所定の比例ゲインを乗算じ、積分ゲイン乗算後の値と比例ゲイン乗算後の値を加算して、各電圧指令値Ｖｄ，Ｖｑを出力する。 The two-phase current calculation means 21 converts the current values iv and iu into d-phase and q-phase current values id and iq using the electrical angle θ as shown in the following equation (1). The converted d-phase and q-phase current values id and iq are output to the proportional-plus-integral control unit 22.

The proportional-integral control unit 22 calculates each current target value id *, iq * and each current value id, iq deviation εd, εq, and integrates the calculated deviation εd, εq to a predetermined integral value. Is multiplied by the integral gain, and each deviation εd, εq is multiplied by a predetermined proportional gain, and the value after multiplication of the integral gain and the value after multiplication of the proportional gain are added to output each voltage command value Vd, Vq. To do.

また、このモータ制御部は、電圧指令リミッタ２７を備えており、この電圧指令リミッタ２７は、三相変換演算手段２３が出力する上記各電圧指令値Ｖｕ，Ｖｖ，Ｖｗのうち、ＰＷＭ開度が全開、すなわち、ＰＷＭデューティ比が最大値以上となる場合に、ＰＷＭデューティ比を最大値とする値に電圧指令値Ｖｕ，Ｖｖ，Ｖｗを制限する。 Further, the d-phase voltage command value Vd and the q-phase voltage command value Vq are input to the three-phase conversion calculation means 23 that converts the voltage command values of the U, V, and W phases as described above. The conversion calculation means 23 converts the d-phase voltage command value Vd and the q-phase voltage command value Vq into actual U, V, W phase voltage command values Vu, Vv, Vw by the calculation of the following equation (2). The converted voltage command values Vu, Vv, and Vw are output to the PWM circuit 25.

The motor control unit includes a voltage command limiter 27. The voltage command limiter 27 has a PWM opening degree among the voltage command values Vu, Vv, and Vw output from the three-phase conversion calculation unit 23. When fully open, that is, when the PWM duty ratio is greater than or equal to the maximum value, the voltage command values Vu, Vv, and Vw are limited to values that maximize the PWM duty ratio.

  Each unit other than the PWM circuit 25 of the control unit 20 amplifies each signal output by hardware, specifically, for example, the current detector 24, the rotation angle sensor 15, and various sensors necessary for vehicle body posture control. Amplifier, converter for converting analog signal into digital signal, storage device such as CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), crystal oscillator and these It is configured as a well-known computer system (not shown) provided with a bus line that can output voltage command values Vu, Vv, Vw to the PWM circuit 25. In addition, each part other than the PWM circuit 25 of the control part 20 as this hardware may be integrated into ECU mounted in a vehicle.

  In this case, the processing procedure for performing the vehicle body posture control for calculating the target value in the current target value calculation unit 26 and the processing procedure for performing the efficiency charging control and field weakening control to be described later are a ROM or a program. Prestored in another storage device.

  By the way, in this electromagnetic suspension device, when the rotor R of the motor M rotates, the magnetic flux of the driving magnet 14 of the rotor R crosses the winding 12, so that an induced electromotive force is generated in the winding 12 and a regenerative current flows. The current due to the power source E provided in the PWM circuit 25 and the regenerative current due to the induced electromotive force flow through the winding 12. However, the regenerative power that can charge the power source E by the induced electromotive force of the winding 12 of the motor M is generated. The regenerative region K that can be performed is a range surrounded by the stroke speed axis and the tangent line S that is in contact with the stroke speed and load curve in the short circuit characteristic T through the origin, and as shown in FIG. This can be determined by the short-circuit characteristic T which is the relationship between the stroke speed and the load of the electromagnetic suspension device in the state.

  The rotational speed of the rotor R of the motor M is proportional to the relative speed of the screw shaft 1 and the ball screw nut 2, that is, the stroke speed of the electromagnetic suspension device, and the output torque of the motor M depends on the load of the electromagnetic suspension device. Since it is proportional, the short circuit characteristic T is obtained by converting the short circuit characteristic, which is the relationship between the rotational speed and torque of the motor M itself, into the relationship between the stroke speed and the load of the electromagnetic suspension device. In the present specification, the term “short-circuit characteristic” refers to the relationship between the stroke speed and the load of the electromagnetic suspension device when the motor is short-circuited as described above unless otherwise specified.

  Here, the stroke speed is the linear relative movement speed of the ball screw nut 2 in the axial direction with respect to the screw shaft 1, and the load is the straight line between the screw shaft 1 and the ball screw nut 2 generated by the torque generated by the motor M. It is a force that suppresses or promotes relative movement.

  In FIG. 4, on the stroke speed axis, when the stroke speed in the direction in which the electromagnetic suspension device contracts is positive for convenience, the right side of the origin indicates the stroke speed in the contraction direction, and the electromagnetic suspension device extends. If the stroke speed is a negative value for convenience, the left side of the origin indicates the stroke speed in the extension direction. On the other hand, if the load in the direction of extending the electromagnetic suspension device is positive for the load axis for the sake of convenience, the portion above the origin indicates the load in the expansion direction, and the load in the direction of contracting the electromagnetic suspension device is negative for convenience. The value below the origin indicates the load in the contraction direction.

  Accordingly, in FIG. 4, the first quadrant shows a state in which the electromagnetic suspension device strokes in the contracting direction, but generates a load that suppresses the stroke, and the second quadrant shows the electromagnetic suspension device. Indicates a state in which a load is generated in a direction that promotes the stroke while a stroke is generated in the extending direction, and the third quadrant is a load that suppresses the stroke in the extending direction. The fourth quadrant shows a state in which a load that promotes the stroke is generated while the stroke is in the contracting direction.

  As described above, the regenerative region K is a range (shaded area in FIG. 4) surrounded by the stroke speed axis and the tangent line S that passes through the origin and touches the stroke speed and load curve in the short circuit characteristic T. Further, the inclination at the tangent S includes the torque constant of the motor M and the overall resistance of the winding 12 and the PWM circuit 25, that is, the internal resistance of the lead wire in addition to the resistor in the circuit. However, since the value is determined by the overall resistance, the regeneration region K can also be determined by setting the torque constant and the overall resistance. Further, the inclination of the tangent S can be adjusted by the lead of the screw shaft 1.

  Note that a horizontal line a that determines the maximum or minimum load of each quadrant in FIG. 4 is a load-generating region determined by limiting the q-phase current target value iq * calculated by the current target value calculation unit 26. The curve b is also a line that divides the area where the load can be generated from the area where the load is impossible.

  The short-circuit characteristic T described above draws a curve in which the load reaches a peak at a certain stroke speed as the stroke speed is increased, and the load gradually decreases as the stroke speed increases thereafter. . That is, until the load peak is reached, the current obtained by power generation caused by forcibly rotating the rotor R of the motor M flows through the windings 12 of each phase so as to effectively generate torque that suppresses the stroke. However, when the stroke speed is increased to the extent that the load peak is exceeded, the reactive current that does not contribute to torque increases and the load decreases. This does not affect the regeneration region K.

  Note that the overall resistance of the winding 12 and the PWM circuit 25 of the motor M, that is, the overall resistance including the internal resistance of the lead wire in addition to the resistors in the circuit, and further the lead of the screw shaft 1 are changed. The short-circuit characteristic T can be compressed and expanded along the stroke speed axis. If the resistance is decreased or the lead of the screw shaft 1 is decreased, the short-circuit characteristic T is compressed toward the origin along the stroke speed axis. On the contrary, if the resistance is increased or the lead of the screw shaft 1 is increased, the short-circuit characteristic T is extended toward the high speed side along the stroke speed axis, whereby the inclination of the tangent S can be changed. . Further, if the torque constant is increased, the inclination of the tangent line S can be increased, and conversely, if the torque constant is decreased, the inclination of the tangent line S can be decreased. In particular, by reducing the overall resistance, increasing the torque constant, reducing the lead of the screw shaft 1, or any combination thereof, the electromagnetic suspension device can achieve a stroke speed. Even if it is low, a large load is obtained, and the regenerative region K also becomes large.

  In this electromagnetic suspension device, the short-circuit characteristic T is set so that the load reaches a peak below the stroke speed that is frequently used while the vehicle is running, that is, the load in the short-circuit characteristic T is within the frequently used stroke speed range. Is set to take the maximum value.

  Then, the regenerative region K within the stroke speed range that frequently appears while the vehicle is running increases, so that the opportunity for charging the power source E by regeneration can be increased, and energy regeneration by the motor M can be performed efficiently. This can ensure power saving.

  In addition, in this electromagnetic suspension device, there is no need for special control in order to perform efficient regeneration, so that the behavior of the vehicle is not switched for the purpose of power saving control, and the vehicle is boarded. It is possible to improve the riding comfort in the vehicle without causing the person to feel uncomfortable or uneasy.

  Here, in the vehicle, a spring element is interposed between the unsprung member and the sprung member in order to make it difficult to transmit vibration input to the unsprung member to the sprung member during traveling of the vehicle. In order to suppress the vibration, a shock absorber is usually interposed between the unsprung member and the sprung member, and the extension side and the contraction side of the shock absorber applied to a light, small, and ordinary automobile are used. From FIG. 5 showing the setting frequency state of the generated load, on the extension side, there are many shock absorbers that generate a load in the range of 200N to 1000N centering around 600N, and on the contraction side, about 0N to 600N centering around 300N. There are many shock absorbers that generate a load within the range, and in order to suppress the vehicle body vibration as described above, the shock absorber needs to generate a load of about 1000 N on the expansion side and about 600 N on the contraction side. is there.

  Moreover, from FIG. 6 which shows the frequency of the expansion / contraction stroke speed of the shock absorber during traveling of the vehicle, the shock absorber is -0.1 m / s, assuming that the contraction side stroke speed is a negative value and the expansion side stroke speed is a positive value. Is frequently used within a stroke speed range of 0.1 m / s.

  As can be understood from the above, the stroke speed frequently used in the expansion and contraction of the shock absorber is within the range of 0.1 m / s (in the case where a positive or negative sign is attached in the expansion and contraction direction, it is 0 to 0.1 m / s or more. .. Within a range of 1 m / s or less), and the required generated load is 1000 N or less.

  Therefore, specifically, the frequently used stroke speed range in which the load in the short-circuit characteristic T of the electromagnetic suspension device has a peak is set to a range in which the expansion / contraction stroke speed is 0.1 m / s or less.

  Accordingly, since the regeneration region K within the stroke speed range that frequently appears during vehicle travel increases, the opportunity for charging the power source E by regeneration can be increased, and energy regeneration by the motor M can be performed efficiently. Needless to say, the power saving can be ensured, and further, the riding comfort in the vehicle can be improved. However, the electromagnetic suspension device can be obtained by standardizing the frequently used stroke speed range in this way. This improves the versatility and reduces the manufacturing cost.

  At this time, if the tangent S is set so as to pass above a point where the stroke speed is 0.1 m / s and the load is 1000 N, the stroke in which the electromagnetic suspension device is frequently used. The entire load range that needs to be generated as a shock absorber within the speed range is covered in the regeneration region K.

  Therefore, in the case where the electromagnetic suspension device is frequently used, when the electromagnetic suspension device is frequently used, the power source E is always regenerated and the power source E is not consumed and the power of the power source E is not consumed. It is possible to reliably save power, prevent a situation where the power source E is raised, and further, it is optimal for a vehicle using a drive source such as an electric vehicle as a motor.

  In the electromagnetic suspension device configured as described above, the stroke load-load characteristic that can charge the power source E most efficiently in the regeneration region K is as shown in FIG. A straight line A passing through the origin having an inclination of one half of the inclination of the tangent line S in contact with the curve of stroke speed and load in the short-circuit characteristic T.

  Here, as shown in FIG. 8, the regenerative current generated with respect to the load generated at an arbitrary stroke speed is the maximum value at half the maximum load that can be generated in the regenerative region K. Therefore, the regenerative efficiency is maximized when the electromagnetic suspension device generates a load that is half the maximum value of the load that can be generated in the regenerative region K with respect to an arbitrary stroke speed. Charging can be performed most efficiently. It can be easily understood from FIG. 8 that the locus of the point determined by the arbitrary stroke speed and the load that achieves the maximum regenerative efficiency with respect to the stroke speed is the straight line A.

  Therefore, the maximum rate charging load, which is the load that maximizes the charging efficiency of the power source E by the power generation of the motor M, is a load that is on the straight line A with respect to an arbitrary stroke speed as described above.

  Therefore, in this electromagnetic suspension device, the stroke speed axis side area Y from the straight line A of the regeneration area K in the first quadrant and the third quadrant in FIG. 9 with respect to the stroke speed (shaded area in FIG. 9). When a load is generated within the motor, that is, when the required load that the electromagnetic suspension device should output for an arbitrary stroke speed is less than the most efficient charging load, the power source E is effectively turned close to the maximum value and the power source E is efficiently turned on. Efficiency charging control is performed by controlling the current flowing through the motor M so that charging is possible.

  In this efficiency charging control, as described above, when the motor M is controlled by the dq phase current, only the q phase generates a magnetic field that contributes to the torque of the motor M. The generated load is determined by the magnitude of the q-phase current, and the d-phase current does not contribute to the torque. Therefore, when a certain load is generated for a certain stroke speed in the region Y, the q-phase current is While the load is generated, when the q-phase current alone is insufficient for the maximum value of the regenerative current, the regenerative current is brought close to the maximum value by flowing a current that does not contribute to torque to the d-phase. Here, when the current flowing in the d phase is controlled to set the regenerative current to the maximum value, the power source E can be charged most efficiently. Then, the above-described efficient charging control allows the electromagnetic suspension device to charge the power source E most efficiently while generating an arbitrary load in the region Y.

  In addition, in the range other than the region Y within the regeneration region K, the load generated for an arbitrary stroke speed exceeds the load for the arbitrary stroke speed on the straight line A, and the d-phase current is controlled. However, the regenerative current does not reach the maximum value.

  Actually, the current target value calculation unit 26 calculates the q-phase current target value according to the control law of the vehicle body posture control, and the d-phase current to be supplied to the d-phase based on the stroke speed and the q-phase current target value. A reference value is calculated, a d-phase efficiency charge reference value is calculated by multiplying the d-phase current reference value by the first gain k1 and the second gain k2, and the d-phase efficiency charge reference value is used for field weakening control to be described later. The d-phase field weakening reference value calculated based on this is added to calculate the d-phase current target value, and the q-phase and d-phase current target values are output. Until the field weakening control is performed, the value of the d-phase field weakening reference value is 0, and in the state where only the efficiency charging control is performed, the d-phase efficiency charging reference value becomes the d-phase current target value.

  Hereinafter, the calculation of the d-phase current target value during the efficiency charging control by the current target value calculation unit 26 will be described in detail. First, the current target value calculation unit 26 calculates the q-phase calculated according to the control law of the vehicle body attitude control. From the current target value and the stroke speed, it is determined whether the load that the electromagnetic suspension device is to generate is within the above-described region Y. Actually, since the load is determined by the q-phase current, as shown in FIG. 10, the straight line A separating the region Y is replaced with the relationship between the stroke speed and the q-phase current, and the region Y is changed to the region Y ′. It is preferable to make the above determination based on the calculated q-phase current target value and the stroke speed by converting.

  When determining whether or not the load is within the region Y, a map representing the relationship between the q-phase current and the stroke speed is stored in a storage device, and the current target value calculation unit 26 stores the map. The determination may be made by referring to the map and performing map calculation.

When the load generated with respect to the stroke speed is within the region Y, the current target value calculation unit 26 calculates the d-phase current reference value. Specifically, assuming that the combined vector of the q-phase current and the d-phase current that maximizes the regenerative current in advance is idq and the d-phase current reference value is idk, the d-phase current reference value idk = (idq ² −iq * ² ) Calculated by ^1/2 .

上記式（３）の関係から電気角θを０から２πまで変化させると、二相電流ｉｄ，ｉｑの極大値は、三相電流ｉｕ，ｉｖ，ｉｗの（３／２）^１／２となることが分かる。 Here, the relationship between the two-phase currents id, iq and the three-phase currents iu, iv, iw of the actual winding 12 of the motor M can be expressed by the relationship of the expression (3).

When the electrical angle θ is changed from 0 to 2π from the relationship of the above formula (3), the maximum values of the two-phase currents id and iq become (3/2) ^1/2 of the three-phase currents iu, iv and iw. I understand that.

When these relationships are evaluated by a combined vector of the d-phase current and the q-phase current, the size of the combined vector idq is set to the size of any one of the three-phase currents iu, iv, iw ( 3/2) It is equal to the product of ^1/2 .

  Accordingly, when the electromagnetic suspension device generates a load at which the regenerative current takes a maximum value with respect to an arbitrary stroke speed based on the relationship between the combined vector idq and the three-phase currents iu, iv, and iw, that is, the stroke speed. -By obtaining the effective current values of the three-phase currents iu, iv, iw when the load characteristic is in the straight line A, the stroke speed and the regenerative current are maximized as shown in FIG. The relationship with the composite vector idq can be obtained in advance.

  Since the d-phase current does not affect the generated load as described above, first, if the q-phase current target value iq * is calculated from the load to be generated with respect to the stroke speed, it is shown in FIG. As described above, the d-phase current reference value idk can be calculated as described above from the combined vector idq that maximizes the regenerative current and the q-phase current target value iq *.

  That is, since the d-phase current reference value idk is calculated based on the composite vector idq, it is not necessary to perform complicated calculation so that the regenerative current becomes the maximum value each time.

  Subsequently, the current target value calculation unit 26 multiplies the d-phase current reference value idk calculated as described above by the first gain k1 and the second gain k2 to obtain the d-layer current target value id *. Calculate.

  As shown in FIG. 12, the first gain k1 described above has a value of 1 when the stroke speed is within a predetermined speed range, and is 0 according to the stroke speed when the stroke speed exceeds the predetermined speed range. It is set to gradually decrease to 0 and gradually decrease to 0 according to the stroke speed when the stroke speed falls below the predetermined speed range. That is, the first gain k1 regulates the range in which the efficient charging control is performed with respect to the stroke speed.

  The predetermined speed range is arbitrarily set, but basically, two are set in order to perform efficient charge control in the first quadrant and the third quadrant in FIG.

  Further, the predetermined speed range does not include the range where the stroke speed is 0, and the predetermined speed range lower limit and the third quadrant in the first quadrant so that the first gain k1 can always have a value of 0 near the origin. The upper limit of the predetermined speed range is set to have a certain distance from the origin so that the first gain k1 can be gradually decreased from 1 to 0. This is because the region Y extends from the origin to the first and third quadrants, so that when the electromagnetic suspension device expands and contracts near the stroke speed 0, the d-phase current becomes oscillating and the control becomes complicated. Since it becomes impractical, such control is prevented from being performed. As can be understood from the above, the first gain k1 increases within the predetermined speed range by exceeding the lower limit of the predetermined speed range in the first quadrant or the upper limit of the predetermined speed range in the third quadrant as the stroke speed during expansion / contraction increases. When this happens, the efficiency charging control is faded in, and on the other hand, the stroke speed during expansion / contraction decreases and becomes below the predetermined speed range lower limit in the first quadrant or the upper limit of the predetermined speed range in the third quadrant, and deviates from the predetermined speed range. When this happens, the function of fading out the efficient charge control is exhibited.

  The upper limit of the predetermined speed range in the first quadrant and the lower limit of the predetermined speed range in the third quadrant are stroke speeds at which field-weakening control, which will be described later, is started. The first gain k1 is the stroke speed during expansion / contraction. Increases and exceeds the upper limit of the predetermined speed range in the first quadrant and the lower limit of the predetermined speed range in the third quadrant, the efficiency charge control is faded out. On the contrary, the stroke speed during expansion / contraction decreases, and the first quadrant If the upper limit of the predetermined speed range and the lower limit of the predetermined speed range in the third quadrant exceed the predetermined speed range, the function of fading in the efficiency charging control is also exhibited.

  In turn, the second gain k2 will be described. The second gain k2 changes depending on the q-phase current target value iq *. Specifically, as shown in FIG. 13, the second gain k2 changes in proportion to the absolute value of the q-phase current target value within a range where the absolute value of the q-phase current target value is not less than 0 and not more than an arbitrary value. However, it is set to 1 in a range that is equal to or greater than the above arbitrary value.

  Here, since the q-phase current target value is a value that determines the load generated by the electromagnetic suspension device, the q-phase current target value promotes the contraction of the electromagnetic suspension device in the first and fourth quadrants in FIG. When the time changes so as to generate a load from the direction to suppress to the direction to suppress, the q-phase current target value changes so as to turn from minus to plus. At this time, the q-phase current target value is the stroke speed axis. When taking a positive value in the vicinity, it becomes a small value. If the regenerative current is set to the maximum value in this state, the current to be supplied to the d phase becomes large.

  As described above, when the electromagnetic suspension device repeatedly expands and contracts when the stroke speed is near 0, the q-phase current target value also repeats vibration near the stroke speed axis in FIG. 10, and as a result, the d-phase current reference value is also the maximum value of 0. The control is complicated and becomes impractical because it vibrates in between, so that such control is prevented from being performed.

  On the other hand, when the q-phase current target value decreases and enters the region Y ′ in FIG. 10, it enters the region Y ′ through the line having the regenerative current as the maximum value only with the q-phase current. In such a case, since the absolute value of the d-phase current reference value gradually increases as the q-phase current target value decreases, the second gain k2 is such that the q-phase current target value is greater than or equal to an arbitrary value. Then there is no need to change.

  As described above, at the time of this efficiency charge control, the load necessary for performing vehicle body attitude control on the electromagnetic suspension device by controlling the current flowing in the d phase with the d phase efficiency charge reference value as the d phase current target value. Since the regenerative current can be increased while generating energy, it is possible to increase the efficiency of energy regeneration by the motor M and increase the charging efficiency of the power source E.

  And, since the power supply E is efficiently charged, the load necessary for the vehicle body posture control is not affected at all, so that the vehicle body posture control is switched without sacrificing the ride comfort in the vehicle. As a result, there is no sense of incongruity or anxiety by letting a vehicle occupant sense vibrations or the like when control is switched.

  Moreover, in this electromagnetic suspension device, since efficient charging of the power source E is possible, it is possible to reliably achieve power saving, and a hybrid vehicle equipped with a motor and a gasoline engine to improve fuel efficiency. It is most suitable for an electric vehicle that is driven entirely by a motor. In particular, when the power source E is a vehicle battery, if the voltage of the power source E decreases, a motor such as a hybrid vehicle is used as a drive source. However, according to this electromagnetic suspension device, since the power source E can be charged efficiently, the traveling property of such a vehicle can be improved.

  Furthermore, when the d-phase current is controlled so that the regenerative current is maximized during the efficiency charging control as in the above-described embodiment, the charging efficiency is maximized, and thus the above-described effects are enhanced.

  In calculating the d-phase efficiency charging reference value, the d-phase current reference value is multiplied by the first and second gains k1 and k2. However, only the first gain k1 or only the second gain k2 is multiplied by the d-phase. Even if the current reference value is multiplied or not multiplied by any of the gains k1 and k2, the power supply E can be efficiently charged, so that the effect of the present invention is not lost.

  In addition, if the inclination of the tangent S is increased, the advantage that the power source E can be charged at the frequently used stroke speed is obtained, and further, the area and the area of the region Y are also increased. Is preferably set as in the present embodiment, but the power supply E can be efficiently charged in the region Y in the present invention without necessarily setting it as such.

  In this electromagnetic suspension device, the power source E can be efficiently charged by performing the efficient charging control as described above. However, the regeneration region K is expanded, and the posture of the vehicle is maintained even when the stroke speed is low. In order to generate a load to be controlled, it is necessary to increase the torque constant to some extent. However, increasing the torque constant increases the amount of power generation.

  Therefore, the controllable curve P that determines the controllable region W in the second and fourth quadrants becomes smaller as the stroke speed at which the induced electromotive force generated in the winding 12 of the motor M exceeds the voltage of the power source E is reduced as it is. The load that can be generated in the second and fourth quadrants is reduced, and as a result, the controllable area is reduced.

  Therefore, in this electromagnetic suspension device, field weakening control is performed in order to shift the stroke speed at which the induced electromotive force generated in the winding 12 of the motor M exceeds the voltage of the power source E to the high speed side.

  The field weakening control is performed when the induced electromotive force exceeds or exceeds the voltage of the power source E in a state where the motor M is controlled in accordance with a normal control law.

  More specifically, in this field weakening control, since a small negative current is applied to the d phase to reduce the magnetic flux, the power generation amount is also reduced.

  Then, by this field weakening control, the controllable curve P in FIG. 14 is shifted to the field weakening control time curve P ′, and the controllable region W is expanded. Further, as shown in FIG. 4, the controllable curve P partitions the regeneration area K of the first quadrant and the third quadrant, so that the controllable curve P is shifted to the weak field control time curve P ′ by the weak field control. The regeneration area K can be enlarged.

  Therefore, according to this electromagnetic suspension device, the short-circuit characteristic T and the torque constant are set so as to expand the regenerative region K within the frequently used stroke speed range, and as a result, the torque constant increases and the induced electromotive force increases. Even in the case where the stroke speed exceeding the voltage of the power supply E becomes low, it is possible to prevent the controllable area W of the second and fourth quadrants from decreasing, and at the same time, the regeneration area K is expanded and consumed. Electric power can be reduced.

  In addition, since the controllable area W in the second and fourth quadrants is originally an active control area, the electromagnetic suspension device cannot generate a sufficient load during active control. There is no invitation.

  In this field-weakening control, specifically, the current value to be supplied to the d phase is determined by the current target value calculation unit 26. In the current target value calculation unit 26, the rotation angle θ input from the rotation angle sensor 15 is determined. , The pitch of the screw shaft 1 obtained by differentiating and the induced electromotive force at which the expansion / contraction stroke speed of the electromagnetic suspension device obtained based on the speed reduction ratio exceeds the voltage of the power source E if the reduction gear is used. The field-weakening control is performed when the speed becomes Z or when the speed reaches a speed Z ′ lower than the absolute value of the speed Z.

  The speeds Z and Z ′ are specifically the upper limit value of the absolute value of the predetermined speed range where the change of the first gain k1 in the efficiency charging control starts, and specifically, in the first quadrant. The upper limit of the predetermined speed range and the lower limit value of the predetermined speed range in the third quadrant are set. When the upper limit of the predetermined speed range in the first quadrant and the lower limit of the predetermined speed range in the third quadrant are different, the speeds Z and Z ′ are set to different values in the first and third quadrants. You may make it do.

  When the field weakening control is performed, specifically, the current target value calculation unit 26 calculates the d-phase field weakening reference value in addition to the d-phase efficiency charging reference value based on the efficiency charging control. The d-phase current target value is calculated by adding the phase efficiency charging reference value and the d-phase field weakening reference value. Subsequently, the proportional-integral control unit 22 calculates the d-phase voltage command value and the q-phase voltage command value, and the three-phase conversion calculation means 23 calculates the d-phase voltage command value and the q-phase voltage command value for each of U, V, and W. This is performed by converting the phase voltage command value to the PWM circuit 25, whereby the controllable region W and the regeneration region K are expanded.

  Further, when the field weakening control is performed when the speeds Z and Z ′ are recognized, the d-phase weakening is proportional to the current target value calculation unit 26 in proportion to the magnitude where the absolute value of the stroke speed exceeds the speeds Z and Z ′. The field reference value is gradually reduced to the negative side, and when the absolute value of the stroke speed exceeds the speed Z, Z ′ and reaches an arbitrary speed, the d-phase field weakening reference value is set to a predetermined value of the negative current, and thereafter The increase to the absolute value of the stroke speed is fixed to the predetermined value. The arbitrary speed may be set to a value that is optimal for the vehicle through experiments or the like, and the predetermined value is set to a value that does not cause demagnetization of the motor M.

  In this way, by gradually increasing the degree of field weakening according to the stroke speed, the field weakening control is turned on and off in the vicinity of speed Z as compared to the case where speed d is set to the d-phase field weakening reference value suddenly. Even in such a case, the d-phase current becomes excessively vibrational and the control is prevented from becoming complicated, and the practicality is improved.

  Here, as described above, the speeds Z and Z ′ are set to the upper limit of the absolute value of the predetermined speed range that determines the range in which the efficiency charging control is performed. It is possible to fade in the weak charge field control while fading out the efficient regenerative control or fade in the efficient charge control while fading out the weak field control. The d-phase efficiency charging reference value in the state where the efficiency charging control is performed has the same sign as the d-phase field weakening reference value in the field weakening control in each of the first quadrant and the third quadrant. In addition, since the q-phase currents in the first quadrant and the third quadrant are opposite to each other, the signs of the d-phase efficiency charging reference value and the d-phase field weakening reference value are the first quadrant and the third quadrant accordingly. And the opposite sign.

  By the way, as described above, the d-phase current target value is the sum of the d-phase efficiency charging reference value and the d-phase field weakening reference value. If this value is too large, the motor M is demagnetized. There is a risk. Therefore, in this embodiment, a limiter 28 for clamping the d-phase current target value to the clamp value is provided. This clamp value is a value determined by the demagnetization resistance of the motor M, and the limiter 28 reduces the demagnetization of the motor M in a state where one or both of the efficiency charge control and the field weakening control are mixed. It is surely prevented.

  And when performing field-weakening control from the time of recognizing the speed | rate Z which generate | occur | produces the induced electromotive force in which the expansion-contraction stroke speed exceeds the voltage of the power supply E, the controllable area | region W and the regeneration area | region K can be expanded. Therefore, since it is possible to secure the controllable region W while increasing the regenerative region K and region Y when the torque constant is increased and the stroke speed is low to increase the charging efficiency, the power supply charging efficiency of the electromagnetic suspension device can be secured. It is possible to achieve a high level of compatibility with the ride comfort in the vehicle.

  In addition, when field weakening control is performed from the point of time when the speed Z ′ at which the expansion stroke speed exceeds the voltage of the power supply E is generated, in addition to the effect of field weakening control from the speed Z, the stroke speed Even if the speed suddenly increases in the vicinity of the speed Z, the field-weakening control is performed first, and the controllable area W is expanded in each quadrant. A situation in which shortage occurs can be prevented, and the ride comfort in the vehicle can be improved. In particular, since there is no load shortage during active control, vehicle body posture control can be reliably performed.

  In the efficiency charging control and field weakening control, the d-phase efficiency charging reference value and the d-phase field weakening reference value are changed linearly, but these are changed smoothly and curvedly. Of course, you can do it. For the above-described advantages, the d-phase field weakening reference value is changed as described above in the d-phase field weakening control. However, when the field-weakening control becomes necessary, the d-phase current target value is set to a predetermined value. However, the effect of enabling the controllable area W and the regeneration area K to be expanded is not lost.

  Further, the electromagnetic suspension device is, like the other electromagnetic suspension devices shown in FIG. 15, the cylinder 31 that is one member, the rod 32 that is the other member that exhibits relative movement with respect to the cylinder 31, and at least suppressing the relative movement. You may make it comprise with possible motor M2.

  Specifically, the cylinder 31 is connected to one of a sprung member and an unsprung member of the vehicle, and a rod 32 connected to the other of the sprung member and the unsprung member of the vehicle is passed through the cylinder 31. .

  The motor M2 includes a driving magnet 33 that is mounted on the outer periphery of the rod 32 so that S poles and N poles appear alternately in the axial direction, and a winding 34 that faces the driving magnet 33 in the cylinder 31. The windings 34 are arranged so that the U, V, and W phases are alternately arranged along the axial direction of the cylinder 31 over a predetermined length.

  Note that the winding 34 provided in the cylinder 31 is formed in an annular shape, and at least the inner peripheral side is coated with resin or the like. The inner periphery of the winding 34 and the outer periphery of the rod 32 or the drive magnet 33 An annular bearing (not shown) is disposed between them, and the shaft 32 is prevented from shaking with respect to the cylinder 31.

  That is, in this other electromagnetic suspension device, a so-called linear motor type configuration in which the drive magnet 33 moves relative to the winding 34 when the rod 32 advances and retreats relative to the cylinder 31 and exhibits relative motion. Even in the other electromagnetic suspension devices, similarly to the electromagnetic suspension device in the above-described embodiment, the motor M2 functions as both a motor and a generator. It is the same.

  Therefore, also in this other electromagnetic suspension device, the above-described efficient charge control and field-weakening control are possible, and by doing so, the same operational effects as the electromagnetic suspension device in the above-described one embodiment can be achieved.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a conceptual diagram of the electromagnetic suspension apparatus in one embodiment. It is a system diagram of the control part in an electromagnetic suspension apparatus. It is a figure which shows a PWM circuit. It is a figure which shows a regeneration area | region. It is a figure which shows the setting frequency situation of the generation | occurrence | production load of the expansion | extension side and shrinkage | contraction side of the buffer applied to a light, small size, and a normal vehicle. It is a figure which shows the frequency of the expansion-contraction stroke speed of the buffer during driving | running | working of a vehicle. It is a figure which shows the stroke load-load characteristic which can charge a power supply most efficiently. It is a figure which shows the relationship between the regenerative current and load in arbitrary stroke speeds. It is the figure which showed the area | region which performs efficient charge control by the relationship between stroke speed and a load. It is the figure which showed the area | region which performs efficient charge control by the relationship between stroke speed and q phase current. It is a figure which shows the relationship between the stroke speed and the synthetic | combination vector of d phase current and q phase current which makes regenerative current the maximum value. It is a figure which shows the relationship between a 1st gain and stroke speed. It is a figure which shows the relationship between a 2nd gain and q phase current target value. It is a figure which shows the controllable area | region of this electromagnetic suspension apparatus. It is a conceptual diagram of another electromagnetic suspension apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw shaft which is one member 2 Ball screw nut 10 which is another member Frame 11 Stator core 12, 33 Winding 13 Shaft 14, 34 Driving magnet 15 Rotation angle sensor 20 Control part 21 Two-phase current calculation means 22 Proportional integral control part 23 Phase conversion calculation means 24 Current detector 25 PWM circuit 26 Current target value calculation unit 27 Voltage command limiter 28 Limiter 31 Tube 32 as one member Rod 41 as the other member Switching element E Power supply M Motor R Rotor

Claims (13)

In an electromagnetic suspension device including one member, the other member exhibiting relative motion with respect to the one member, and a motor capable of suppressing at least the relative motion, the charging efficiency of the power source by the power generation of the motor is maximized with respect to the stroke speed. When the necessary load to be output is lower than the most efficient charging load, which is the load, the efficiency charging control is performed by controlling the d-phase current so that the charging efficiency is higher than the charging efficiency when the necessary load is generated while generating the necessary load. Electromagnetic suspension device. The electromagnetic suspension device according to claim 1, wherein the efficiency charging control is performed by controlling the d-phase current so that the charging efficiency is maximized. 3. The efficiency charging control is performed by controlling the d-phase current based on a dq-phase current composite vector for generating the most efficient charging load with respect to the stroke speed and a q-phase current necessary for generating the required load. The electromagnetic suspension device described in 1. Based on the map of the stroke speed and the value corresponding to the dq-phase composite vector that generates the most efficient charging load with respect to the stroke speed, and the q-phase current target value necessary for generating the required load, the d-phase current target value is 4. The electromagnetic suspension device according to claim 1, wherein the electromagnetic suspension device is calculated. 5. The electromagnetic suspension device according to claim 1, further comprising a limiter configured to clamp the d-phase current target value when the d-phase current target value becomes lower than the clamp value. 6. The electromagnetic suspension device according to claim 1, wherein the efficiency charging control is performed within a predetermined speed range of the stroke speed. The d-phase current target value is calculated by multiplying the d-phase current reference value calculated from the dq-phase composite vector and the q-phase current target value by the first gain, and when the stroke speed exceeds the predetermined speed range, it depends on the stroke speed. 7. The electromagnetic suspension device according to claim 1, wherein the first gain is gradually reduced to zero. The electromagnetic suspension device according to any one of claims 1 to 7, wherein when the stroke speed falls below a predetermined speed range, the first gain is gradually reduced to 0 according to the stroke speed. The d-phase current target value is calculated by multiplying the d-phase current reference value by the second gain or by multiplying the d-phase current reference value by the first gain and the second gain, and the absolute value of the q-phase current target value is 0. 9. The electromagnetic suspension device according to claim 1, wherein the second gain is proportional to the absolute value of the q-phase current target value within a range that is not more than the arbitrary value. 10. The electromagnetic suspension device according to claim 1, wherein when the stroke speed exceeds a predetermined speed range, the field weakening control is faded in to control the d-phase current. The d-phase field weakening current reference value calculated based on the field weakening control faded in when the stroke speed exceeds the predetermined speed range and the d-phase efficiency charging reference value calculated based on the efficiency charging control faded out. The electromagnetic suspension device according to claim 10, wherein the d-phase current target value is calculated by addition. The electromagnetic suspension apparatus according to any one of claims 6 to 11, wherein the upper limit of the predetermined speed range is set to at least a stroke speed at which an induced electromotive force of the motor is equal to or higher than a power supply voltage. The one member exhibits a rotational motion when the other member exhibits a linear relative motion with respect to the one member and the other member, and the rotational motion of the one member is transmitted to the motor. The electromagnetic suspension device described.

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