JP2011025804A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device properly operating an electromagnetic actuator to control the behaviors of an unsprung member and a sprung member, and to efficiently store regenerative electric power. <P>SOLUTION: An electromagnetic actuator control device 41 determines that the regenerative electric power obtained from an electric motor 26 is in a large condition when the unsprung vertical acceleration Gl detected by an unsprung vertical acceleration sensor 44 is larger than a determination reference value Go. In this condition, the control device 41 changes to increase the field-weakening gain Ky for weakening the magnetic field to extend the control range by increasing the energizing amount of d-axis component of the motor 26. The control device 41 makes the DC-DC converter 62 in the electric power unit 60 to decrease the driving voltage supplied to a motor driving circuit 47 and a capacitor 63. Hence the control range of the motor 26 is extended by increasing the gain Ky, thereby the capacitor 63 efficiently stores the regenerative electric power. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a suspension device for a wheel of an automobile or the like, and in particular, a suspension device including an electromagnetic actuator having an electric motor that generates an actuator force that is a force in a direction toward or away from an unsprung member and an unsprung member. About.

  2. Description of the Related Art In recent years, active research has been conducted on converting and recovering (regenerating) kinetic energy generated by traveling of a vehicle into electric energy, and storing the regenerated electric energy in a power storage means for effective use.

  For example, in Patent Document 1 below, in a hybrid vehicle that travels with a driving force obtained from an engine and an electric motor, when the hybrid vehicle travels in a downward section, the amount of power stored in the power storage means that stores power by regenerative energy is disclosed. It has been shown that the width (SOC: State Of Charge) is larger than the management width during normal running and power storage is performed with more regenerative energy. And by expanding the management range of the amount of electricity stored in this way, the amount of electricity stored by regenerative energy can be increased, and the efficiency of the entire run is improved.

  Further, for example, in Patent Document 2 below, in an electromagnetic suspension device provided with an electromagnetic actuator, the damping force by the electromagnetic suspension is changed according to the power supply capability of the in-vehicle power supply device, and the power supply voltage of the in-vehicle power supply device sets the reference voltage. In the situation below, it is shown that the damping force is reduced to increase the expansion and contraction motion of the electromagnetic suspension, and the amount of power generated by the electric motor is increased to improve the regeneration efficiency. Thereby, even if it is a case where the power supply capability of a vehicle-mounted power supply device falls, the regenerated electric power can be stored in a vehicle-mounted power supply device.

  Further, in Patent Document 3 below, in a suspension system including an electromagnetic actuator, when a current is supplied from a power source to a motor, the d-axis current component is increased based on the state of charge of the power source, thereby It has been shown that overcharging of the power supply can be avoided without significantly changing the actuator force generated by. Thus, the regenerated power can be efficiently charged by reducing the d-axis current component when the power source needs to be charged and increasing the d-axis current component when the power source is overcharged.

JP 2005-160269 A JP 2007-161100 A JP 2009-40244 A

  By the way, in each apparatus described in the said patent documents 1-3, although regenerative energy, more specifically, regenerative electric power can be stored and used effectively, the point of the regenerative efficiency which stores regenerative power is stored. There is room for improvement. That is, in the hybrid vehicle described in Patent Document 1, the number of changes in the management width is regulated from the viewpoint of protecting the power storage means (specifically, the battery). That is, in this hybrid vehicle, there are cases where the management width cannot be changed because the number of changes is restricted, and in this case, regenerative power cannot be stored. In the suspension devices and suspension systems described in Patent Documents 2 and 3, regenerative power is not stored when the on-vehicle power supply (power supply) is fully charged. In particular, in these suspension devices and suspension systems, for example, when the vehicle travels, the electromagnetic suspension frequently expands and contracts due to external force from the road surface, that is, the frequency at which regenerative power is obtained is high. ), There is a high possibility that the regenerative power is wasted.

  In this case, for example, it is conceivable to change the management range of the power storage of the in-vehicle power supply device (power supply) as in the hybrid vehicle described in Patent Document 1, but as described above, the in-vehicle power supply device (power supply) Since the number of changes is limited from the viewpoint of protecting the vehicle, it is not compatible with suspension devices and suspension systems that frequently generate regenerative power. Accordingly, it is desirable to efficiently store and use the regenerative electric power particularly in a suspension device including an electromagnetic actuator.

  The present invention has been made in order to cope with the above-described problems, and an object of the present invention is to appropriately operate the electromagnetic actuator to control the behavior of the unsprung member and the sprung member, and to generate the regenerative power from the electromagnetic actuator. An object of the present invention is to provide a suspension device that efficiently stores electricity.

  In order to achieve the above object, a feature of the present invention is a direction that is arranged between an unsprung member and a sprung member of a vehicle and approaches or separates from the unsprung member and the sprung member. An electromagnetic actuator having an electric motor that generates an actuator force, a motor drive circuit for driving the electric motor of the electromagnetic actuator by a power source from a vehicle power supply device, and operating the motor drive circuit to control the electromagnetic In a suspension device comprising a control device for controlling the actuator force by the electric motor of an actuator, the vehicle power supply device is supplied from the main power supply device, and a main power supply device that mainly supplies power to the motor drive circuit Power transformation means for transforming the power source to be supplied and supplying the transformed power source to the motor drive circuit, and the power transformation means A sub-power supply device that is rechargeable by output and discharges the stored electrical energy and supplies power to the motor drive circuit, and the unsprung member and the unsprung member approach or separate from each other. Regenerative power determination means for determining the magnitude of regenerative power directed to the vehicle power supply device side via the motor drive circuit due to the electromotive force generated by the electric motor of the electromagnetic actuator, and the regenerative power determination means When it is determined that the regenerative power is large, the gain changing means for changing the gain related to the drive control of the electric motor of the electromagnetic actuator, and when the regenerative power determination means determines that the regenerative power is large, The power supplied from the main power supply to the motor drive circuit and the sub power supply is stepped down with respect to the power transformer. In that a power down control means for causing. In this case, the auxiliary power supply device of the vehicle power supply device may be a capacitor or an electric double layer capacitor, for example.

  In this case, for example, the power supply step-down control means controls the drive of the electric motor of the electromagnetic actuator in a state where the power supplied from the main power supply device to the motor drive circuit is stepped down by the power supply transformation means. For this purpose, after the gain is changed by the gain changing means, it is preferable to step down the power supplied from the main power supply device to the motor drive circuit and the sub power supply device with respect to the power supply transformation means.

  Further, in this case, the sprung vertical acceleration detecting means for detecting the vertical acceleration of the sprung member in the vehicle vertical direction, and the unsprung vertical acceleration detecting means for detecting the vertical acceleration of the unsprung member in the vehicle vertical direction; The regenerative power determination means includes a magnitude of the vertical acceleration of the sprung member detected by the sprung vertical acceleration detection means and a vertical acceleration of the unsprung member detected by the unsprung vertical acceleration detection means. When comparing at least the magnitude of the vertical acceleration of the unsprung member with a preset criterion value, and when the magnitude of the vertical acceleration of the unsprung member is greater than the criterion value, It is determined that the regenerative power from the electric motor of the electromagnetic actuator toward the vehicle power supply device via the motor drive circuit is large. When may.

  In this case, motor rotation speed detecting means for detecting the rotation speed of the electric motor of the electromagnetic actuator is further provided, and the regenerative power determination means rotates the electric motor detected by the motor rotation speed detection means. When the magnitude of the speed is compared with a preset criterion value, and the magnitude of the rotational speed of the electric motor is larger than the criterion value, the electric motor of the electromagnetic actuator passes through the motor drive circuit. Therefore, it may be determined that the regenerative power toward the vehicle power supply device side is large.

  Further, in this case, further, a current detection means for detecting a current flowing through the power transformer means of the vehicle power supply device is provided, and the regenerative power determination means is a current flowing through the power transformer means detected by the current detection means. When the direction of the main power supply is directed to the main power supply device, the magnitude of the current flowing through the power transformer means detected by the current detector means is compared with a preset criterion value, and the power transformer means When the magnitude of the flowing current is larger than the determination reference value, it is preferable to determine that the regenerative power from the electric motor of the electromagnetic actuator toward the vehicle power supply device via the motor drive circuit is large.

  Furthermore, the gain related to the drive control of the electric motor of the electromagnetic actuator changed by the gain changing means is, for example, a proportional gain and an integral gain in PI control, and a current component flowing in the electric motor of the electromagnetic actuator Field gain for increasing / decreasing the current component in the d-axis direction, and when the regenerative power determining means determines that the regenerative power is large, the gain changing means at least reduces the field weakening gain. It is preferable to increase the current component in the d-axis direction flowing through the electric motor.

  According to these, when it is determined by the regenerative power determination means that the regenerative power going from the electric motor of the electromagnetic actuator to the vehicle power supply device side via the motor drive circuit is large, the power supply step-down control means is changed from the main power supply device to the motor drive circuit. The electric energy stored in the sub power supply device (capacitor) from the main power supply device can be reduced by lowering the power supplied to the sub power supply device (capacitor). As a result, the amount of electrical energy that can be stored in the sub power supply device (capacitor) can be relatively increased, and regenerative power (electric energy) traveling from the electric motor of the electromagnetic actuator to the vehicle power supply device side through the motor drive circuit. In other words, the backflow current toward the vehicle power supply device side can be preferentially stored in the sub power supply device (capacitor) with priority. Since the stored regenerative power (electric energy) is released and supplied to the motor drive circuit as a power source, the recovered regenerative power can be used very effectively.

  In addition, surplus regenerative power (electrical energy) is generally consumed as heat by providing a dynamic brake (D / B), etc., but can be efficiently stored and used in a secondary power supply (capacitor). Thus, it is possible to significantly reduce the amount of wasted regenerative power consumed as heat. In addition, since the regenerative power is efficiently stored and used by the sub power supply device (capacitor), the size of the dynamic brake (D / B) and the like can be reduced, and as a result, downsizing of the device is also achieved. be able to.

  On the other hand, when the power supplied from the main power supply device is stepped down, the drive voltage for driving the electric motor of the electromagnetic actuator is lowered, so that the response of the electric motor of the electromagnetic actuator is lowered and the control range is reduced. There is a concern to do. However, in this regard, the gain changing means is a weak field for increasing or decreasing the gain related to the drive control of the electric motor of the electromagnetic actuator, for example, the proportional gain and the integral gain in the PI control, and the current component in the d-axis direction. By changing the magnetic gain, it is possible to prevent the response of the electric motor of the electromagnetic actuator from decreasing and the control range from decreasing. Therefore, even when the drive voltage is lowered by reducing the power supply from the main power supply device, the electric motor of the electromagnetic actuator can be appropriately driven, and the unsprung member and the unsprung member are approached. Alternatively, an appropriate actuator force in the direction of separation can be generated. Thereby, the behavior of the unsprung member and the sprung member can be appropriately controlled.

1 is a system configuration diagram of a suspension device according to an embodiment of the present invention. It is sectional drawing which shows schematic structure of the suspension main body of FIG. It is a circuit diagram of the motor drive circuit which drives the electric motor of the electromagnetic actuator of FIG. It is a flowchart which shows the regeneration control program performed by the electromagnetic actuator control apparatus of FIG. It is a graph which shows the relationship between unsprung vertical acceleration and regenerative electric power. It is a figure for demonstrating the reduction | decrease of the control range accompanying a drive voltage fall, and the expansion of the control range by a field weakening. It is a graph which shows the relationship between the rotational speed of an electric motor, and a field weakening gain. It is the figure which showed notionally the accumulation | storage amount of the regenerative electric power (electrical energy) by the capacitor | condenser which increases relatively by reducing a drive voltage.

  Hereinafter, a suspension device according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows the system configuration of the suspension device according to the present embodiment. As shown in FIG. 1, the suspension device includes four sets of suspension bodies 10FL, 10FR, 10RL, 10RR provided between the wheels WFL, WFR, WRL, WRR and the vehicle body B, respectively. Note that the suspension bodies 10FL, 10FR, 10RL, and 10RR and the wheels WFL, WFR, WRL, and WRR have the same configuration, and therefore are simply referred to as the suspension body 10 and the wheels W in the following description.

  As shown in FIG. 2, the suspension body 10 is transmitted from the road surface to the vehicle body B via the wheels W by using an electromagnetic actuator 20 as an electromagnetically controlled shock absorber and the elasticity (compressibility) of air. And an air spring device 30 that improves the ride comfort by absorbing vibrations. One end (upper end) of the electromagnetic actuator 20 and the air spring device 30 is connected to the sprung member HA, and the other end (lower end) of the electromagnetic actuator 20 is connected to the unsprung member LA. Here, a knuckle connected to the wheel W, a lower arm having one end connected to the knuckle, and the like correspond to the unsprung member LA. The sprung member HA is a member supported by the electromagnetic actuator 20 and the air spring device 30, and the vehicle body B is also included in the sprung member HA.

  The electromagnetic actuator 20 includes an outer cylinder 21 and an inner cylinder 22 that are arranged coaxially. The outer cylinder 21 and the inner cylinder 22 are formed of, for example, coaxial different-diameter pipes, and the outer cylinder 21 is slidably assembled on the outer peripheral surface of the inner cylinder 22 as shown in FIG. . A ball screw mechanism 23 is accommodated inside the inner cylinder 22.

  The ball screw mechanism 23 includes a ball screw 24 that rotates by a rotating operation of an electric motor 26 described later, and a ball screw nut 25 having a female screw portion 25a that is screwed into a male screw portion 24a formed on the ball screw 24. The ball screw nut 25 is regulated by a non-illustrated detent so that it cannot rotate. Thereby, in this ball screw mechanism 23, the rotational motion of the ball screw 24 is converted into the linear motion in the vertical axis direction of the ball screw nut 25, and conversely, the linear motion in the vertical axis direction of the ball screw nut 25 is converted into the ball screw nut. It is converted into 24 rotational movements.

  Further, as shown in FIG. 2, the lower end of the ball screw nut 25 is fixed to the bottom surface of the outer cylinder 21. As the electric motor 26 rotates, the ball screw 24 rotates and the ball screw nut 25 moves up and down. Then, the outer cylinder 21 is pulled down or pulled up. Conversely, when an external force is applied to the ball screw 24 to move the outer cylinder 21 in the axial direction, the ball screw 24 rotates and the electric motor 26 rotates. Here, the electric motor 26 is, for example, a three-phase DC brushless motor. When the electric motor 26 is rotated with the rotation of the ball screw 24 by an external force, the permanent magnets provided on the rotor are electromagnetic coils CL1 to CL3 (on the stator). 3), an electromotive force (electric energy) is generated in the electromagnetic coils CL1 to CL3 to act as a generator.

  The upper end of the inner cylinder 22 is assembled to the mounting plate 27. The mounting plate 27 is fixed to the motor casing 26a of the electric motor 26, and the ball screw 24 is inserted into a through hole 27a formed at the center thereof. The ball screw 24 is connected to the motor shaft in the motor casing 26 a and is rotatably supported by a bearing 28 in the inner cylinder 22.

  The air spring device 30 is provided on the outer periphery of the electromagnetic actuator 20, and includes a cylindrical upper case 31 surrounding the outer peripheral surface of the motor casing 26 a, a lower case 32 surrounding the outer peripheral surface of the outer cylinder 21, and both cases 31. , 32 are connected to each other in an airtight state, and a diaphragm 33 mainly composed of rubber is formed, and an air chamber 34 is formed on the outer periphery of the outer cylinder 21, the inner cylinder 22 and the motor casing 26a by the cases 31, 32 and the diaphragm 33. To do. The upper case 31 and the lower case 32 are hermetically welded to the outer peripheral surfaces of the motor casing 26a and the outer cylinder 21, respectively, so that the air chamber 34 is sealed.

  In addition, the upper case 31 is provided with a supply / discharge port 35 as a supply / discharge port for supplying and exhausting air into the air chamber 34. As shown in FIG. 1, a supply / exhaust pipe 51 serving as a high-pressure air flow path is connected to the supply / discharge port 35 from a supply / exhaust device 50 described later. The air pressure is adjusted. The suspension body 10 thus configured is assembled to the vehicle body B via the upper support 36 made of an elastic material on the upper surface of the upper case 31.

  Here, in the suspension main body 10 configured as described above, when the sprung member and the unsprung member approach and separate as the vehicle travels, the outer cylinder 21 and the inner cylinder 22 of the electromagnetic actuator 20 Moves relative to the axial direction. Thus, when the outer cylinder 21 and the inner cylinder 22 move relative to each other, as described above, the ball screw 24 rotates relative to the ball screw nut 25, so that the ball screw 24 and the ball screw nut 25 are also axial. Move relative to. Then, a rotational torque is applied to the ball screw 24 from the electric motor 26.

  Therefore, by appropriately changing the rotational torque generated by the electric motor 26, a resistance force that inhibits the stroke operation is generated with respect to the relative operation (stroke operation) between the sprung member HA and the unsprung member LA. be able to. Thereby, the electromagnetic actuator 20 functions as a shock absorber by applying this resistance force as a damping force for the stroke operation of the sprung member HA and the unsprung member LA. That is, the electromagnetic actuator 20 has a function of applying a damping force to the stroke operation by an actuator force that is an axial force generated by itself. On the other hand, the electromagnetic actuator 20 also has a function of applying the actuator force as a propulsive force, that is, a driving force for the stroke operation.

  With these functions, a control based on the so-called skyhook damper theory, in which a damping force or a driving force proportional to the absolute speed of the sprung member HA is applied to the operation of the sprung member HA, and the unsprung member LA It is possible to execute control based on a pseudo ground hook theory in which a damping force or a driving force proportional to the absolute speed of the unsprung member LA is applied to the operation.

  Further, the electromagnetic actuator 20 positively changes the distance between the sprung member HA and the unsprung member LA in the vertical direction by the actuator force, and sets the distance between the sprung member HA and the unsprung member LA to a predetermined distance. It also has a function to maintain. With this function, as will be described later, the vibration behavior (heave behavior) in the vertical direction of the sprung member HA (vehicle body B), the roll behavior of the sprung member HA (vehicle body B) during turning, and the sprung member during acceleration / deceleration It is possible to effectively suppress the pitch behavior of the HA (vehicle body B) and adjust the vehicle height.

  Next, the suspension control device 40 that controls the operation of each suspension body 10 will be described with reference to FIG.

  The suspension control device 40 controls the driving of the electromagnetic actuator 20 (more specifically, the electric motor 26), and the high-pressure air to the air spring device 30 to control the vehicle height of the vehicle to a predetermined value. And a vehicle height adjustment control device 42 to be maintained. Each of the electromagnetic actuator control device 41 and the vehicle height adjustment control device 42 includes a microcomputer including a CPU, a ROM, a RAM, a timer, and the like as main components, and executes the various programs to thereby change the electromagnetic actuator 20 and the air spring device 30. Control.

  The suspension control device 40 includes a sprung vertical acceleration sensor 43, an unsprung vertical acceleration sensor 44, a motor rotation angle sensor 45, and a vehicle height sensor 46. The sprung vertical acceleration sensor 43 is assembled in the vicinity of, for example, the upper support 36 corresponding to each wheel position, detects the vertical acceleration of the sprung member HA at each wheel position, and detects the detected vertical motion. A sprung vertical acceleration signal corresponding to acceleration (hereinafter referred to as sprung vertical acceleration Gh) is output. The unsprung vertical acceleration sensor 44 is assembled in the vicinity of the lower arm in correspondence with each wheel position, for example, detects the vertical acceleration of the unsprung member LA at each wheel position, and detects the detected vertical acceleration ( Hereinafter, the unsprung vertical acceleration signal corresponding to the unsprung vertical acceleration Gl) is output. The motor rotation angle sensor 45 detects the rotation angle of the electric motor 26 and outputs a motor rotation angle signal corresponding to the detected rotation angle (hereinafter referred to as the motor rotation angle θ). The vehicle height sensor 46 detects, for example, the relative position in the vertical direction of the sprung member HA with respect to the unsprung member LA, and outputs a vehicle height signal corresponding to the relative position. In this embodiment, the sprung vertical acceleration sensor 43, the unsprung vertical acceleration sensor 44, and the motor rotation angle sensor 45 are connected to the input side of the electromagnetic actuator control device 41, and the vehicle height sensor 46 is the vehicle height adjustment device 42. Is connected to the input side.

  The suspension control device 40 includes a motor drive circuit 47 that controls the drive of each electromagnetic actuator 20 (more specifically, the electric motor 26). The motor drive circuit 47 constitutes a three-phase inverter circuit, and as shown in FIG. 3, switching elements SW11 respectively corresponding to the electromagnetic coils CL1, CL2, CL3 of the electric motor 26 connected in a star connection (Y connection). , SW12, SW21, SW22, SW31, SW32. The switching elements SW11, SW12, SW21, SW22, SW31, and SW32 correspond to the switching elements SW11, SW21, and SW31 on the high side (high potential side) and the switching elements SW12, SW22, and SW32 on the low side (low potential side), respectively. In addition, each of the three phases of the electric motor 26 corresponds to the U phase, the V phase, and the W phase, and is configured by, for example, a MOSFET. The motor drive circuit 47 is provided with a current sensor for detecting the value of the current flowing through the electric motor 26 in each phase.

  The switching elements SW11, SW12, SW21, SW22, SW31, and SW32 are on / off controlled by a signal from the electromagnetic actuator control device 41. Therefore, in this motor drive circuit 47, the power (energization) from the power supply device 60 described later to the electric motor 26 is controlled by controlling the pulse width of the switching elements SW11, SW12, SW21, SW22, SW31, SW32 (PWM control). Amount) and the amount of electromotive force that is sent back from the electric motor 26 to the power supply device 60 side, that is, the amount of regenerative power (electric energy).

  The supply / discharge device 50 is controlled by the vehicle height adjustment control device 42 and includes a compressor (not shown) or the like, compresses air, and supplies high-pressure air to the air spring device 30. As shown in FIG. 1, a supply / exhaust pipe 51 having one end connected to the supply / discharge device 50 and the other end connected to the air spring device 30 via the supply / discharge port 35 is an electromagnetic valve that opens and closes the flow path. 52 and a pressure sensor 53 for detecting the pressure in the flow path are provided. As a result, the vehicle height adjustment control device 42 controls the operation of the compressor and the electromagnetic valve 52 of the supply / discharge device 50 to adjust the pressure in the air chamber 34 of the air spring device 30 to adjust the vehicle height to the target position. maintain.

  Note that the specific vehicle height adjustment function by the vehicle height adjustment control device 42 is not directly related to the present invention and will be briefly described below. The vehicle height adjustment function by the vehicle height adjustment control device 42 is realized, for example, when the vehicle height (set vehicle height) is changed by the driver's intention. That is, the distance between the sprung member HA and the unsprung member LA at each wheel position is set according to the target set vehicle height, and the vehicle height adjustment control device 42 includes the vehicle height sensor 46 and the pressure sensor 53. Based on the detected value, the operation of the supply / discharge device 50 is controlled so that the distance between the sprung member HA and the unsprung member LA becomes the target distance at each wheel position. The vehicle height adjustment function also includes so-called auto leveling control for the purpose of coping with changes in vehicle height due to, for example, changes in the number of passengers and changes in load capacity.

  The power supply device 60 is connected to the electric motor 26 via the motor drive circuit 47 as shown in FIG. 3 and is connected to the supply / discharge device 50 to supply power. A battery 61 as a main power supply device is provided. And a DC-DC converter 62 as a power source transformer and a capacitor 63 as a sub power source device. The battery 61 supplies power to the motor drive circuit 47 (that is, the electric motor 26) and the supply / discharge device 50 at normal times, and stores regenerative power from the electric motor 26. The DC-DC converter 62 transforms (steps down or boosts) the power (voltage) supplied from the battery 61 and transforms (steps up or steps down) the regenerative power (regenerative voltage) from the electric motor 26. The capacitor 63 stores (charges) electrical energy (power) supplied from the battery 61 via the inverter 62 to supply power to the motor drive circuit 47 (that is, the electric motor 26), and also regenerates from the electric motor 26. Electric power is stored.

  Next, the operation of the suspension body 10 (more specifically, the electromagnetic actuator 20) whose operation is controlled by the electromagnetic actuator control device 41 will be described. The operation of the suspension body 10 itself is not directly related to the present invention, and will be briefly described below.

  The electromagnetic actuator control device 41 independently controls the four suspension bodies 10 (electromagnetic actuators 20) in order to suppress the above-described heave behavior, roll behavior, and pitch behavior. That is, the electromagnetic actuator control device 41 generates each electromagnetic actuator 20 to suppress the actuator force and roll behavior that each electromagnetic actuator 20 should generate in order to suppress the heave behavior that occurs as the vehicle travels. In order to suppress the power actuator force and the pitch behavior, the actuator force to be generated by each electromagnetic actuator 20 is summed to determine the target actuator force. The electromagnetic actuator control device 41 drives and controls the electric motor 26 via the motor drive circuit 47 so that each electromagnetic actuator 20 generates a target actuator force.

  In the following description, the actuator force (each component described later) has a positive value corresponding to the force in the direction in which the sprung member HA and the unsprung member LA are separated (rebound direction). The value corresponding to the force in the direction (bound direction) that causes the member HA and the unsprung member LA to approach each other is set to a negative value.

  First, the control for suppressing the heave behavior will be briefly described. In this control, the sprung member HA (vehicle body B) and the unsprung member LA (based on the skyhook damper theory and the pseudo groundhook theory described above are used. In order to attenuate the vibration of the wheel W), an actuator force having a magnitude corresponding to the speed of the vibration is generated. Specifically, the electromagnetic actuator control device 41 inputs the sprung vertical acceleration signal from the sprung vertical acceleration sensor 43 assembled to the sprung member HA, and receives the unsprung vertical acceleration signal from the unsprung vertical acceleration sensor 44. input.

Then, the electromagnetic actuator control device 41 integrates the sprung vertical acceleration Gh and the unsprung vertical acceleration Gl represented by the input sprung vertical acceleration signal and unsprung vertical acceleration signal, respectively, so that the vertical motion of the sprung member HA is increased. The operation speed in the direction (hereinafter referred to as the sprung speed Vs) and the operation speed in the vertical direction of the unsprung member LA (hereinafter referred to as the unsprung speed Vg) are calculated. Thereby, the electromagnetic actuator control device 41 calculates an actuator force that suppresses the heave behavior (hereinafter referred to as a heave suppression component Fv) according to the following formula 1 using the calculated sprung speed Vs and unsprung speed Vg.
Fv = Cs ・ Vs−Cg ・ Vg… Formula 1
However, Cs in Formula 1 is a gain for generating an actuator force (a damping force or a driving force) according to the vertical movement speed of the sprung member HA (vehicle body B), and Cg is an unsprung portion. This is a gain for generating an actuator force (a damping force or a driving force) according to the vertical movement speed of the member LA (wheel W).

Next, control for suppressing roll behavior will be described. In this control, the sprung member HA on the turning inner ring side and the unsprung member LA are separated from each other by the roll moment generated as the vehicle turns, and the sprung member HA and unsprung member LA on the turning outer ring side are separated from each other. An actuator force having a magnitude that suppresses the approaching state is generated. That is, in this control, the actuator force in the bound direction is generated as the roll restraining force in the electromagnetic actuator 20 on the inner side of the turning and the actuator force in the rebound direction on the electromagnetic actuator 20 on the outer side of the turning. Specifically, the electromagnetic actuator control device 41 calculates an actuator force that suppresses roll behavior (hereinafter referred to as a roll suppression component Fr) according to the following equation 2.
Fr = Kr · Gy Equation 2
However, Kr in the formula 2 represents a gain set in advance for the roll behavior, and Gy represents, for example, a lateral acceleration generated in a vehicle in a turning state.

Next, control for suppressing the pitch behavior will be described. In this control, the sprung member HA on the front wheel side and the unsprung member LA are separated (or approached) by the pitch moment generated at the time of acceleration / deceleration of the vehicle, and the sprung member HA and the unsprung member LA on the rear wheel side. An actuator force having a magnitude that suppresses the state in which they approach (or separate) is generated. That is, in this control, the front wheel side electromagnetic actuator 20 is controlled in the bounce (or rebound direction) actuator force, and the rear wheel side electromagnetic actuator 20 is in the rebound (or bounce direction) actuator force. Generate as force. Specifically, the electromagnetic actuator control device 41 calculates an actuator force that suppresses the pitch behavior (hereinafter referred to as a pitch suppression component Fp) according to the following Equation 3.
Fp = Kp · Gx Equation 3
However, Kp in the expression 3 represents a gain set in advance with respect to the pitch behavior, and Gx represents, for example, the acceleration in the front-rear direction generated in the vehicle in the acceleration / deceleration state.

When the heave suppression component Fv, the roll suppression component Fr, and the pitch suppression component Fp are calculated in this way, the electromagnetic actuator control device 41 calculates a target actuator force Fa * that is a control target value obtained by adding these components Fv, Fr, and Fp. Is calculated according to Equation 4 below.
Fa * = Fv + Fr + Fp Equation 4

  When the electromagnetic actuator control device 41 calculates the target actuator force Fa *, the so-called vector control is performed on the electric motor 26 via the motor drive circuit 47 so that each electromagnetic actuator 20 generates the target actuator force Fa *. Drive control according to the law. In the vector control method, the current, voltage, and the like in the three phases of the electric motor 26 are converted into a component in the d-axis direction that is parallel to the direction of the magnetic field generated by the permanent magnet provided on the rotor of the electric motor 26, and the direction of the magnetic field. Is a control method in which it is converted into a two-phase value with a component in the q-axis direction, which is a direction orthogonal to. Since the vector control method itself is well known, detailed description of the point of converting the current and voltage in three phases into two phases and the point of converting the current and voltage in two phases into three phases is omitted. .

  The electromagnetic actuator control device 41 calculates the current motor rotation angle θ of the electric motor 26 input from the motor rotation angle sensor 45 and the estimated motor rotation angle θ ′ of the electric motor 26 in the next calculation cycle, and the input motor rotation. The rotational speed ω of the electric motor 26 is calculated by differentiating the angle θ with respect to time. Then, the electromagnetic actuator control device 41 uses the motor rotation angle θ input from the motor rotation angle sensor 45 to convert the actual currents Iu, Iv, and Iw that are currently flowing through the electric motor 26 into the d-axis based on a known conversion matrix. And q-axis real currents Id and Iq.

  Next, the electromagnetic actuator control device 41 calculates the d-axis target current Id * and the q-axis target current Iq * according to the target actuator force Fa * calculated based on the equation 4. When the electric motor 26 is a three-phase brushless DC motor, the torque generated by the electric motor 26 is proportional to the q-axis actual current Iq of the electric motor 26. Therefore, in a normal time other than when a regenerative control program described later is executed, the electromagnetic actuator control device 41 sets the d-axis target current Id * to “0”, and the q-axis target current Iq * becomes the target actuator force Fa. Calculate in proportion to *. Then, the electromagnetic actuator control device 41 calculates the difference between the actual currents Id and Iq and the target currents Id * and Iq * and matches the actual currents Id and Iq with the target currents Id * and Iq * (that is, the difference) Is set to “0”), the PI gain (proportional gain Kh and integral gain Ks) in the PI control is determined, and the target voltages Vd * and Vq * of the d-axis and the q-axis are calculated.

  When the target voltages Vd * and Vq * for the d-axis and the q-axis are calculated in this way, the electromagnetic actuator control device 41 calculates the target voltage Vd *, Vq *, based on the calculated estimated motor rotation angle θ ′ of the electric motor 26. Vq * is converted into three-phase target voltages Vu *, Vv *, and Vw *. Then, the electromagnetic actuator control device 41 determines a target duty ratio Du *, Dv *, Dw * based on the converted three-phase target voltages Vu *, Vv *, Vw *, and this duty ratio Du *. , Dv * and Dw * are output to the motor drive circuit 47. In the motor drive circuit 47, the switching of the switching elements SW11, SW12, SW21, SW22, SW31, and SW32 is controlled to be switched by the PWM method based on the output command signal, that is, the duty ratio Du *, Dv *, Dw *. The three-phase target voltages Vu *, Vv *, Vw * are converted into three-phase AC voltages Iu, Iv, Iw, and an actuator force that matches the target actuator force Fa * is generated in the electromagnetic actuator 20 (ie, the electric motor 26). Let

  By the way, for example, when the vehicle travels, an external force that moves the outer cylinder 21 and the inner cylinder 22 relative to the electromagnetic actuator 20 from the road surface, that is, the ball screw nut 25 relative to the ball screw 24 in the axial direction. When an external force to be moved is applied, the ball screw 24 rotates and the electric motor 26 rotates as described above. And by this rotation, the electric motor 26 generates an electromotive force in the electromagnetic coils CL1 to CL3 and functions as a generator. In other words, regenerative electric power is obtained by the electric motor 26 acting as a generator.

  The regenerative power obtained in this manner is stored in the capacitor 63 in the power supply device 60 and is boosted (or stepped down) by the inverter 62 and stored in the battery 61. By the way, each of the battery 61 and the capacitor 63 has a capacity that can be stored, and in a situation where a regenerative power larger than the power storage capacity can be obtained, surplus regenerative power is supplied to, for example, a dynamic circuit provided in the inverter 62. It is generally performed that heat is consumed by the brake (D / B). That is, in the past, surplus regenerative power is wasted as heat. Therefore, the electromagnetic actuator control device 41 efficiently stores regenerative power by executing the regenerative control program shown in FIG. This will be described in detail below.

  When an ignition switch (not shown) is turned on, the electromagnetic actuator control device 41 starts executing the regenerative control program in step S10. In subsequent step S11, the electromagnetic actuator control device 41 determines whether or not the regenerative power W obtained from the electric motor 26 is greater than a predetermined determination reference value Wo. Hereinafter, this determination will be specifically described.

  The situation where the regenerative electric power W generated by the electric motor 26 increases is the amount and frequency of the relative movement of the ball screw 24 and the ball screw nut 25, specifically, the amount and frequency of the ball screw 24 being rotated by an external force. Dependent. That is, the situation where the regenerative power W generated by the electric motor 26 increases depends on the amount and frequency of relative movement of the outer cylinder 21 and the inner cylinder 22. For this reason, the electromagnetic actuator control device 41 detects the unsprung vertical acceleration Gl detected by the unsprung vertical acceleration sensor 44 as a physical quantity related to the relative movement between the outer cylinder 21 and the inner cylinder 22 by an external force input from the road surface. Is used to determine whether or not the magnitude (absolute value) of the unsprung vertical acceleration Gl is larger than the magnitude (absolute value) of a predetermined determination reference value Go.

  That is, as shown in FIG. 5, the electromagnetic actuator control device 41 obtains from the electric motor 26 if the magnitude of the unsprung vertical acceleration Gl input from the unsprung vertical acceleration sensor 44 is larger than the judgment reference value Go. Since the generated regenerative power W is larger than the predetermined determination reference value Wo, the determination is “Yes” and the process proceeds to step S12. On the other hand, if the magnitude of the unsprung vertical acceleration Gl is equal to or smaller than the criterion reference value Go, the electromagnetic actuator control device 41 determines “No”, and the magnitude of the unsprung vertical acceleration Gl is equal to the criterion reference value Go. The determination process of step S11 is repeatedly performed until a situation where the magnitude is larger than the magnitude, that is, a situation where the regenerative power W is greater than the judgment reference value Wo.

  In the determination process in step S11, determination is made using the unsprung vertical acceleration Gl at a specific wheel position among the four unsprung vertical accelerations Gl detected by the unsprung vertical acceleration sensor 44 at each wheel position. Or the average value of the unsprung vertical acceleration Gl on the front wheel side and the rear wheel side, or the average value of the unsprung vertical acceleration Gl of the four wheels.

  In step S <b> 12, the electromagnetic actuator control device 41 changes a gain related to drive control of the electric motor 26. Hereinafter, the gain changing process will be specifically described.

  Under a situation where the regenerative power W is large, the drive voltage of the electric motor 26 is lowered in order to efficiently store the regenerative power in the capacitor 63 of the power supply device 60, as will be described in detail in step S13 described later. On the other hand, in this case, as the drive voltage decreases, the control range decreases as shown in FIG. 6 due to a decrease in responsiveness and generated torque in the drive control of the electric motor 26 by the electromagnetic actuator control device 41. Therefore, in step S12, the electromagnetic actuator control device 41 gains related to drive control of the electric motor 26, specifically, the q-axis actual current Iq, the d-axis actual current Id, and the q-axis target current Iq. The PI gain in PI control according to the difference between * and the d-axis target current Id * and the field weakening gain that changes the magnitude of the d-axis target current Id * are changed. Specifically, the electromagnetic actuator control device 41 changes the PI gain related to the responsiveness of the electric motor 26 so that, for example, the proportional gain Kh and the integral gain Ks are increased. Further, the electromagnetic actuator control device 41 changes the field weakening gain Ky so as to increase in order to increase the control range of the electric motor 26 in a state where the drive voltage is lowered.

  Here, the change of the field weakening gain Ky will be described. In general, in a DC electric motor such as the electric motor 26, the back electromotive force increases as the motor rotational speed ω increases, and it becomes difficult to increase the motor rotational speed ω beyond that. For this reason, in order to reduce the generated back electromotive force, the d-axis target current Id * (that is, the d-axis actual current) that weakens the field force that generates the magnetic field, that is, is normally set to “0”. Increase Id). As a result, the motor rotation speed ω of the electric motor 26 can be increased. As a result, as shown in FIG. 6, the control range (the range that can follow the rotation of the ball screw 24) can be increased. Specifically, as shown in FIG. 7, with respect to the change in the motor rotational speed ω of the electric motor 26, the motor rotational speed ω is set to “0” below a predetermined rotational speed ωo, which is higher than the rotational speed ωo. A field-weakening gain Ky that uniformly increases when it is large is set, and the target current Id * of the d-axis when the drive voltage decreases is increased and determined.

  Thus, if the electromagnetic actuator control apparatus 41 changes the gain relevant to the drive control of the electric motor 26, it will progress to step S13. In step S <b> 13, the electromagnetic actuator control device 41 reduces the drive voltage supplied from the battery 61 via the DC-DC converter 62 of the power supply device 60.

That is, the electromagnetic actuator control device 41 controls the DC-DC converter 62 so that the voltage supplied from the battery 61 becomes a drive voltage V2 that is lower than the drive voltage V1 at the normal time. As a result, the downstream side of the DC-DC converter 62 decreases to the drive voltage V2. Meanwhile, the capacitor 63 of the power supply device 60 stores the power (electric energy) supplied from the battery 61 via the DC-DC converter 62. The amount of electrical energy that can power storage in capacitor 63 (electric energy) is, theoretically, the capacitance of the capacitor C, and a voltage between the electrodes is V, represented by CV ^2/2. Therefore, in the state in which the drive voltage supplied from the battery 61 has dropped to a drive voltage V2 from the drive voltage V1, the capacitor 63, as shown conceptually in FIG. 8, at least ^{C (V1-V2) 2/} 2 As a result, a margin of electric energy (electric energy) that can be accumulated is generated. That is, by reducing the drive voltage V1 at the normal time to the drive voltage V2 at the time of power regeneration, the amount of electric energy (power amount) that can be stored in the capacitor 63 is increased. As a result, the regenerative power supplied from the electric motor 26 via the motor drive circuit 47 is preferentially stored in the capacitor 63. In other words, since the amount of regenerative power stored by the battery 61 does not change, the amount of regenerative power stored by the capacitor 63 relatively increases and the amount of sharing increases. In this case, as the electrical characteristics of the capacitor 63, electrical energy (regenerative power) can be stored with extremely small loss, so that the electrical energy (regenerative power) can be stored extremely efficiently. And since the electrical energy (regenerative power) stored in the capacitor 63 forming the power supply device 60 is promptly supplied when the electric motor 26 is driven, the electrical energy (regenerative power) can be used very efficiently. it can.

  As described above, when the drive voltage is decreased from the drive voltage V1 to the drive voltage V2 in step S13, the electromagnetic actuator control device 42 returns to step S11 again. And the electromagnetic actuator control apparatus 41 repeatedly performs each step process after step S11 as mentioned above.

  As can be understood from the above description, according to the present embodiment, the electromagnetic actuator control device 41 lowers the drive voltage for operating the electromagnetic actuator 20, thereby giving priority to the capacitor 63 forming the power supply device 60. The regenerative power can be stored in and processed. As a result, for example, the wasteful regenerative electric energy (electric energy amount) consumed as heat by the dynamic brake (D / B) provided in the DC-DC converter 62 can be significantly reduced. Therefore, the recovered regenerative power can be used very effectively. In addition, since the regenerative power is efficiently stored and used by the capacitor 63, the size of the dynamic brake (D / B) can be reduced, and as a result, downsizing of the device can also be achieved.

  On the other hand, by reducing the drive voltage for operating the electromagnetic actuator 20, there is a concern that the responsiveness of the electric motor 26 constituting the electromagnetic actuator 20 and the control range may be reduced. However, in this regard, the electromagnetic actuator control device 41 changes the gain related to the drive control of the electric motor 26, that is, the proportional gain Kh and integral gain Ks of the PI gain, and the field weakening gain Ky, It is possible to prevent the responsiveness of the electric motor 26 from decreasing and the control range from decreasing. Therefore, even when the drive voltage is lowered, the electromagnetic actuator 20 can be appropriately operated, and the heave behavior, roll behavior, and pitch behavior generated in the vehicle can be appropriately suppressed.

  The implementation of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the above embodiment, in the regeneration control program, when the electromagnetic actuator control device 41 determines “Yes” in the determination process of step S11, the process proceeds to step S12, and after performing the gain change process, the process proceeds to step S13. The drive voltage was lowered. In this case, since the gain changing process in step S12 and the drive voltage lowering process in step S13 are performed electrically instantaneously, for example, the order of step S12 and step S13 is switched to execute the drive voltage lowering process. It is also possible to execute the gain changing process after this. Even in this case, the same effect as the above embodiment can be obtained.

  In the above-described embodiment, in the regeneration control program, the electromagnetic actuator controller 41 uses the unsprung vertical acceleration Gl detected by the unsprung vertical acceleration sensor 44 as a physical quantity in the determination process in step S11. did. That is, in this case, in order to determine the relative movement between the outer cylinder 21 and the inner cylinder 22 due to the action of an external force, in other words, the amount and frequency of rotation of the electric motor 26 accompanying the rotation of the ball screw 24 due to the action of the external force. The unsprung vertical acceleration Gl is used. Therefore, in this case, instead of using the unsprung vertical acceleration Gl, the sprung vertical acceleration Gh detected by the sprung vertical acceleration sensor 43 and the motor rotation angle θ detected by the motor rotation angle sensor 45 The magnitude (absolute value) or the magnitude (absolute value) of the motor rotation speed ω obtained by time differentiation of the motor rotation angle θ is adopted as a physical quantity, and the magnitude of a criterion value set in advance corresponding to these physical quantities It is also possible to carry out the determination in comparison with Even in this case, the same effect as the above embodiment can be obtained.

  In the above embodiment, in the regenerative control program, the electromagnetic actuator control device 41 executes the determination process in step S11 so as to determine whether or not the regenerative power W can be largely obtained. did. In this case, in the circuit diagram shown in FIG. 3, in order to directly detect the magnitude of the regenerative power W, for example, an ammeter (sensor) may be provided in the vicinity of the DC-DC converter 62. . Thereby, the magnitude of the regenerative power W obtained from the electric motor 26 via the motor drive circuit 47 can be directly detected, and the magnitude of the detected regenerative power W and the average value of the regenerative power W within a predetermined time are obtained. When the determination reference value Wo is larger than the preset reference value Wo, each step process after step S12 can be executed. Therefore, also in this case, the same effect as the above embodiment can be obtained.

  Furthermore, in the said embodiment, it implemented so that the power supply device 60 might be provided with the capacitor | condenser 63 as a sub power supply device. In this case, the power supply device 60 can be configured using an element or device capable of storing and discharging regenerative power in the same manner as the capacitor 63. For example, a capacitor (electric double layer capacitor) is used instead of the capacitor 63. It is also possible to implement. Even in this case, the same effect as in the above embodiment can be expected.

DESCRIPTION OF SYMBOLS 10 ... Suspension main body, 20 ... Electromagnetic actuator, 26 ... Electric motor, 40 ... Suspension control apparatus, 41 ... Electromagnetic actuator control apparatus, 44 ... Unsprung vertical acceleration sensor, 45 ... Motor rotation angle sensor, 47 ... Motor drive circuit, 60 ... Power supply device, 61 ... Battery, 62 ... DC-DC converter, 63 ... Capacitor, HA ... Sprung member, LA ... Unsprung member, B ... Vehicle body

Claims (7)

An electromagnetic having an electric motor that is disposed between an unsprung member and an unsprung member of a vehicle and generates an actuator force that is a force toward or away from the unsprung member and the unsprung member. An actuator, a motor drive circuit for driving the electric motor of the electromagnetic actuator by a power source from a vehicle power supply device, and a control device for controlling the actuator force by the electric motor of the electromagnetic actuator by controlling the operation of the motor drive circuit In a suspension device with
A main power supply that mainly supplies power to the motor drive circuit, and a power transformer that transforms the power supplied from the main power supply and supplies the transformed power to the motor drive circuit. A sub-power supply device that can be charged by the output of the power transformer means, and discharges the stored electrical energy to supply power to the motor drive circuit,
Due to the electromotive force generated by the electric motor of the electromagnetic actuator as the unsprung member and the sprung member approach or separate from each other, regenerative electric power directed toward the vehicle power supply device via the motor drive circuit is generated. Regenerative power determination means for determining the magnitude;
Gain changing means for changing a gain related to drive control of the electric motor of the electromagnetic actuator when the regenerative power determining means determines that the regenerative power is large;
When the regenerative power determination means determines that the regenerative power is large, power supply step-down control means for stepping down the power supplied from the main power supply device to the motor drive circuit and the sub power supply device to the power supply transformer means And a suspension device. In the suspension device according to claim 1,
The power supply step-down control means includes
After the gain is changed by the gain changing means to drive and control the electric motor of the electromagnetic actuator in a state where the power supplied from the main power supply device to the motor drive circuit is stepped down by the power transformer means. A suspension device characterized in that the power supplied from the main power supply device to the motor drive circuit and the sub power supply device is stepped down with respect to the power transformation means. The suspension device according to claim 1, further comprising:
A sprung vertical acceleration detecting means for detecting vertical acceleration in the vehicle vertical direction of the sprung member;
An unsprung vertical acceleration detecting means for detecting vertical acceleration in the vehicle vertical direction of the unsprung member,
The regenerative power determination means includes
At least the unsprung size of the magnitude of the vertical acceleration of the sprung member detected by the sprung vertical acceleration detecting means and the magnitude of the vertical acceleration of the unsprung member detected by the unsprung vertical acceleration detecting means. The magnitude of the vertical acceleration of the member is compared with a predetermined criterion value, and when the magnitude of the vertical acceleration of the unsprung member is larger than the criterion value, the motor from the electric motor of the electromagnetic actuator A suspension device, characterized in that it is determined that the regenerative electric power directed toward the vehicle power supply device via the drive circuit is large. The suspension device according to claim 1, further comprising:
Motor rotation speed detecting means for detecting the rotation speed of the electric motor of the electromagnetic actuator;
The regenerative power determination means includes
When the magnitude of the rotational speed of the electric motor detected by the motor rotational speed detecting means is compared with a preset judgment reference value, and the magnitude of the rotational speed of the electric motor is larger than the judgment reference value The suspension device is characterized in that it is determined that a large amount of regenerative power is directed from the electric motor of the electromagnetic actuator toward the vehicle power supply device via the motor drive circuit. The suspension device according to claim 1, further comprising:
Current detecting means for detecting a current flowing through the power transformer means of the vehicle power supply device;
The regenerative power determination means includes
When the direction of the current flowing through the power transformer means detected by the current detector is the direction toward the main power supply device, the magnitude of the current flowing through the power transformer means detected by the current detector and a preset value are set. The vehicle power supply device from the electric motor of the electromagnetic actuator via the motor drive circuit when the magnitude of the current flowing through the power transformer is larger than the determination reference value. It is determined that the regenerative power toward the side is large. In the suspension device according to claim 1,
The gain related to the drive control of the electric motor of the electromagnetic actuator changed by the gain changing means is:
A field weakening gain for increasing or decreasing a proportional gain and an integral gain in PI control, and a current component in the d-axis direction among current components flowing in the electric motor of the electromagnetic actuator;
The gain changing means includes
A suspension device characterized in that, when the regenerative power determination means determines that the regenerative power is large, at least the field weakening gain is increased to increase the d-axis direction current component flowing in the electric motor. In the suspension device according to claim 1,
The auxiliary power device of the vehicle power device is
A suspension device characterized by being a capacitor or an electric double layer capacitor.

Images