JP2007168611A - Suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an overheating of an electromagnetic actuator and a decrease in capability of a power supply device and prevent a sudden change in vehicle behavior due to a stop of a roll suppression control so as not to give a sense of anxiety to a passenger.
When roll suppression control is being performed (S22: YES), if an integrated value ΣAi of an electromagnetic actuator control command exceeds a reference value A0 (S24: YES), roll suppression control is continued as it is. The roll suppression control gain K3 and the vibration suppression control gains K1, K2 are gradually reduced (S27, S28). When the roll suppression control ends, the control gains K1, K2, and K3 are reset to initial values (S31, S32). As a result, it is possible to prevent overheating of the electric motor and the motor drive circuit without causing anxiety to the driver by gradually weakening the roll suppression control.
[Selection] Figure 5

Description

  The present invention relates to a suspension device for a wheel of an automobile or the like, and more particularly to a suspension device that suppresses and controls a change in the attitude of a vehicle by energization control of an electromagnetic actuator.

Conventionally, as shown in, for example, Patent Document 1, an electromagnetic suspension device using an electromagnetic actuator is known as a suspension device that performs vehicle attitude control and vibration suppression control. This electromagnetic suspension device includes an extendable electromagnetic actuator provided between each wheel and the vehicle body, and generates a damping force (the wheel and the vehicle body approach each other) by generating an electric motor when the wheel and the vehicle body approach and separate from each other. -A force for attenuating the separating motion) is obtained, and the electric motor is energized using an in-vehicle battery to adjust the expansion / contraction state of the electromagnetic actuator. Therefore, when the vehicle is turning, roll suppression control can be performed by adjusting the expansion / contraction state of the electromagnetic actuator by energizing the electric motor.
JP 2005-162021 A

However, in the electromagnetic suspension device, when the vehicle turning state continues, the amount of current flowing through the electromagnetic actuator for suppressing the vehicle roll increases. That is, when turning the vehicle, in order to keep the vehicle posture horizontal, one of the left and right wheel electromagnetic actuators is extended and the other electromagnetic actuator is contracted to support the vehicle weight against the roll motion. The amount of current flowing through the electric motor increases. Therefore, if the vehicle turning state continues for a long time, the electric motor or motor drive circuit of the electromagnetic actuator generates heat, or the capacity of the vehicle-mounted battery is reduced due to an increase in power consumption, making it difficult to continue roll suppression control. End up.
In such a case, if the roll suppression control is stopped halfway, the behavior of the vehicle changes suddenly and gives an uneasiness to the occupant.

  An object of the present invention is to cope with the above-described problem, and suppresses overheating of the electromagnetic actuator and a decrease in the capacity of the power supply device, and prevents a sudden change in the vehicle behavior due to the stop of the roll suppression control. The purpose is to avoid anxiety.

  In order to achieve the above object, a feature of the present invention is that it is provided between a wheel and a vehicle body, and receives the force in the vertical direction of the wheel so that the vehicle body and the wheel approach or separate from each other to generate electromagnetic force. An electromagnetic actuator that generates a propulsive force that causes the vehicle body and the wheel to approach or separate from each other by energization from the in-vehicle power supply device, attitude change detection means that detects an attitude change due to a turning motion of the vehicle, In a suspension device comprising an actuator control means for controlling the drive of the electromagnetic actuator by calculating a command value of the drive current of the electromagnetic actuator so as to suppress the posture change, the posture change suppression control by the electromagnetic actuator is not continued. An actuator that includes a state quantity detection means that cannot detect a predetermined state quantity that is estimated to be possible, The control means is configured to detect the state of the electromagnetic actuator when the predetermined state quantity that is estimated to be impossible to continue the attitude change suppression control is detected during the attitude change suppression control of the vehicle. This is to gradually reduce the command value of the drive current.

  According to the present invention configured as described above, the electromagnetic actuator is driven to suppress the posture change due to the turning motion of the vehicle, but during the vehicle posture change suppression control, the control cannot be continued any further. When the estimated state quantity is detected, the command value for the drive current of the electromagnetic actuator is gradually reduced. That is, before the posture change suppression control suddenly stops, the state quantity estimated to be impossible to continue is detected, and the energization amount to the electromagnetic actuator is gradually reduced. Therefore, the posture change suppression control does not suddenly stop and the vehicle behavior does not change suddenly, so that the driver does not feel uneasy.

The electromagnetic actuator includes, for example, a wheel side member connected to the wheel side and a vehicle body side member connected to the vehicle body side, and the wheel side member and the vehicle body side member receive a force in the vertical direction of the wheel. A motor that generates a relative moving force between the wheel-side member and the vehicle body-side member by energization from the in-vehicle power supply device while generating electric power by relative movement to obtain a damping force can be provided.
Further, as a configuration for gradually reducing the command value of the drive current of the electromagnetic actuator, for example, a gain gradually decreasing unit that gradually decreases the control gain that is an element for determining the drive current amount of the electromagnetic actuator may be provided.

  Another feature of the present invention is that the discontinuation state amount detecting means calculates a cumulative amount of a command value of a drive current supplied to the electromagnetic actuator, and the cumulative amount of the command value has reached a predetermined cumulative amount. Sometimes, it is estimated that the posture change suppression control cannot be continued.

According to this, the overheating state of the electromagnetic actuator is estimated from the cumulative amount of the command value of the drive current supplied to the electromagnetic actuator, and the electric actuator is in the overheated state when the cumulative amount of the command value reaches the predetermined cumulative amount. And gradually change the posture change suppression control.
Therefore, it is possible to prevent the suspension device from being broken due to abnormal heat generation of the electromagnetic actuator, and to suppress a sudden change in the vehicle behavior. Moreover, since abnormal heat generation of the electromagnetic actuator can be estimated without providing a special sensor, it can be implemented at low cost.
Further, excessive power consumption from the power supply device can be prevented.

  Another feature of the present invention is that the discontinuation state amount detecting unit detects the state of the in-vehicle power supply device, and the continuation of the posture change suppression control is detected when a predetermined power supply capability decrease is detected. It is to estimate that it is impossible.

According to this, when the capability fall of a vehicle-mounted power supply device is detected, posture change suppression control is loosened gradually. Therefore, excessive power consumption from the in-vehicle power supply device can be suppressed, the suspension system control system is not suddenly stopped due to power shortage, and a sudden change in vehicle behavior can also be suppressed. In addition, problems such as system down of other electric control systems that use the power of the in-vehicle power supply device can be prevented.
In addition, you may detect the fall of the power supply capability of this vehicle-mounted power supply device based on whether a power supply voltage value is more than a predetermined voltage value, for example.

  Another feature of the present invention is that the electromagnetic actuator is provided between the wheel and the vehicle body, is provided with a vehicle height adjusting device that can extend and contract in the vertical direction, and the posture change suppression control cannot be continued. When the estimated drive current command value to be supplied to the electromagnetic actuator is gradually reduced, the vehicle height adjustment device assists the vehicle posture change suppression control.

According to this, when the command value of the drive current supplied to the electromagnetic actuator is gradually lowered, the vehicle posture change suppression control is assisted by the vehicle height adjusting device, so that the vehicle posture change can be favorably suppressed.
As the vehicle height adjusting device, for example, a device that adjusts the vehicle height by fluid pressure without using an electric force, such as an air drive actuator, may be applied.

  Hereinafter, a suspension device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows the system configuration of the suspension device according to the embodiment.

This 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, and the operations of the suspension bodies 10FL, 10FR, 10RL, 10RR. And a suspension control device 50 for controlling the suspension.
Hereinafter, the four sets of the suspension bodies 10FL, 10FR, 10RL, and 10RR and the wheels WFL, WFR, WRL, and WRR are simply collectively referred to as the suspension body 10 and the wheels W unless particularly distinguished from front, rear, left, and right.

As shown in FIG. 2, the suspension body 10 is provided between the lower arm LA that supports the wheel W and the vehicle body B, and absorbs the impact received from the road surface by utilizing the elasticity (compressibility) of air to improve the ride comfort. The air spring device 20 that increases the weight of the vehicle and elastically supports the weight of the vehicle and the electromagnetic actuator 30 that functions as a shock absorber that generates a damping force with respect to the vertical vibration of the air spring device 20.
Hereinafter, the side supported by the air spring device 20, that is, the vehicle body B side is referred to as “sprung”, and the side that supports the air spring device 20, that is, the wheel W side is referred to as “unsprung”.

The electromagnetic actuator 30 includes an outer cylinder 31 and an inner cylinder 32 that are arranged coaxially, a ball screw mechanism 35 provided inside the inner cylinder 32, and an electric motor 40 that operates the ball screw mechanism 35.
The outer cylinder 31 and the inner cylinder 32 are constituted by coaxial different diameter pipes, and the outer cylinder 31 is provided on the outer periphery of the inner cylinder 32 so as to be slidable in the axial direction. In the figure, reference numerals 33 and 34 denote bearings that slidably support the inner cylinder 32 in the outer cylinder 31.

  The ball screw mechanism 35 includes a ball screw 36 that rotates by a rotating operation of the electric motor 40, and a ball screw nut 39 that has a female screw portion 38 that engages with a male screw portion 37 formed on the ball screw 36. The ball screw nut 39 is restricted by a rotation stopper (not shown) so that it cannot rotate. Therefore, in this ball screw mechanism 35, the rotational motion of the ball screw 36 is converted into the linear motion of the ball screw nut 39 in the vertical axis direction. Conversely, the linear motion of the ball screw nut 39 in the vertical axis direction is converted to the ball screw 35. Is converted into a rotational motion.

  The lower end of the ball screw nut 39 is fixed to the bottom surface of the outer cylinder 31. When the ball screw nut 39 moves up and down by the rotation of the electric motor 40, the outer cylinder 31 is pushed down or pulled up. Conversely, when an external force is applied to the ball screw 36 to move the outer cylinder 31 in the axial direction, the ball screw 36 rotates to rotate the electric motor 40. At this time, the electric motor 40 acts as a generator by generating electromotive forces in the electromagnetic coils CL1 to CL3 by causing the permanent magnet provided in the rotor to cross the electromagnetic coils CL1 to CL3 (see FIG. 3) provided in the stator. .

  The upper end of the inner cylinder 32 is fixed to the mounting plate 41. The mounting plate 41 is fixed to the motor casing 42 of the electric motor 40, and the ball screw 36 is inserted through a through hole 43 formed in the center thereof. The ball screw 36 is connected to the motor shaft in the motor casing 42 and is rotatably supported by a bearing 44 in the inner cylinder 32.

When the wheel W moves up and down while the vehicle is running, the outer cylinder 31 slides in the axial direction with respect to the inner cylinder 32, and the ball screw nut 39 moves up and down with respect to the ball screw 36 to move the ball screw 36. Rotate. For this reason, the electric motor 40 rotates and generates an electromagnetic force (electromotive force) to act as a generator. Accordingly, a damping force (a force that attenuates the movement of the wheel W and the vehicle body B approaching / separating) is generated by the resistance force generated for the power generation.
Further, when the electric motor 40 is energized by the power supply device 70, the ball screw mechanism 35 is expanded and contracted to give a propulsive force (relative moving force between the inner cylinder 32 and the outer cylinder 31) to the outer cylinder 31. A predetermined damping force can be generated with respect to the vertical vibration, and a change in vehicle posture can be suppressed. In either case, this can be achieved by adjusting the magnitude of the current flowing through the electric motor 40.

  The air spring device 20 is provided on the outer periphery of the electromagnetic actuator 30 so as to be extendable in the vertical direction. A cylindrical upper case 21 that surrounds the outer periphery of the motor casing 42 and a lower case 22 that surrounds the outer peripheral surface of the outer cylinder 31. And a diaphragm 23 mainly composed of rubber that connects the cases 21 and 22 in an airtight state. These cases 21 and 22 and the diaphragm 23 provide outer peripheries of the outer cylinder 31, the inner cylinder 32, and the motor casing 42. An air chamber 24 is formed. The upper case 21 and the lower case 22 are hermetically welded and fixed to the outer peripheral surfaces of the motor casing 42 and the outer cylinder 31, respectively, so that the air chamber 24 is hermetically sealed.

The upper case 21 is provided with a nozzle 25 as a supply / discharge port for supplying and exhausting air into the air chamber 24. As shown in FIG. 1, a supply / exhaust pipe 81 serving as a high-pressure air flow path from a supply / exhaust device 80 controlled by the suspension control device 50 is connected to the nozzle 25. The air pressure in 24 is adjusted.
The suspension body 10 configured in this manner is attached to the vehicle body B via the upper support 26 made of an elastic material on the upper surface of the upper case 21.

Next, the suspension control device 50 that controls the operation of the suspension body 10 will be described.
FIG. 3 is a block diagram showing the function of the suspension control device 50.

The suspension control device 50 includes an electromagnetic actuator control device 51 that drives and controls the electromagnetic actuator 30 and a vehicle height adjustment control device 52 that drives and controls the air spring device 20 to maintain the vehicle height at a predetermined value. The main part is composed of a microcomputer.
Further, the electromagnetic actuator control device 51 has a ride comfort control unit 51a that calculates a control amount of the electromagnetic actuator 30 so as to ensure good ride comfort by suppressing vertical vibrations of the vehicle, and roll motion of the vehicle. And a safety control unit 51b that calculates a control amount of the electromagnetic actuator 30 so as to maintain a good vehicle posture and ensure steering stability.
The suspension control device 50 is supplied with power by a power supply device 70 including a battery 71 and an alternator 72 as a generator.

  Next, sensors used for the suspension control device 50 to perform various controls will be described. Hereinafter, the sensors provided for each wheel W will be described with the same reference numerals because there is no need to distinguish them.

The suspension control device 50 includes a sprung acceleration sensor 61 (hereinafter referred to as a sprung G sensor 61) that detects a vertical acceleration on a spring as a sensor provided for each wheel W, and a vertical direction below the spring. An unsprung acceleration sensor 62 (hereinafter referred to as unsprung G sensor 62), a vehicle height sensor 63 for detecting a vehicle height from, for example, a relative position in the vertical direction of the spring with respect to the unsprung mass, and an air spring device 20 is connected to a pressure sensor 82 for detecting the pressure in the high-pressure air supply circuit, and as a sensor provided in each vehicle, a lateral acceleration sensor 65 (hereinafter referred to as a lateral acceleration sensor) for detecting the lateral acceleration of the vehicle. G sensor 65) is connected.
The lateral G sensor 65 corresponds to the posture change detecting means of the present invention that detects a posture change caused by a turning motion of the vehicle.
The electromagnetic actuator control device 51 has a function as power supply state detection means for detecting the state of the power supply device 70, and is configured to constantly monitor the output voltage (power supply voltage Vx).

  The suspension control device 50 connects a motor drive circuit 55 that drives and controls the electromagnetic actuator 30 based on detection signals of these various sensors and a supply / discharge device 80 that supplies compressed air to the air spring device 20.

  The motor drive circuit 55 that controls the drive of the electric motor 40 of the electromagnetic actuator 30 constitutes a three-phase inverter circuit. The three-phase electromagnetic coils CL1 and CL2 of the electric motor 40 (which uses a DC brushless motor in this embodiment). , CL3 respectively have switching elements SW11, SW12, SW21, SW22, SW31, SW32. These switching elements SW11, SW12, SW21, SW22, SW31, SW32 are composed of MOS-FETs, and are on / off controlled by signals from the electromagnetic actuator control device 51. The motor drive circuit 55 is provided with current sensors 56a, 56b, and 56c for detecting the value of the current flowing through the electric motor 40 in each phase. Hereinafter, the three current sensors 56a, 56b, and 56c are collectively referred to as a current sensor 56.

  In this motor drive circuit 55, by controlling the duty ratio of the switching elements SW11, SW12, SW21, SW22, SW31, SW32 (PWM control), the energization amount from the power supply device 70 to the electric motor 40 and the electric motor 40 to the battery are controlled. The amount of current of regenerative power sent to the 71 side is controlled.

  The supply / discharge device 80 includes a compressor (not shown) that compresses air to generate high-pressure air. In addition, a supply / exhaust pipe 81 serving as a high-pressure air supply / exhaust path from the supply / exhaust apparatus 80 to each air spring apparatus 20 includes an electromagnetic valve 83 for opening / closing the flow path and a pressure sensor 82 for detecting the pressure in the flow path. Is provided. The vehicle height adjustment control device 52 adjusts the pressure in the air chamber 24 of the air spring device 20 to maintain the vehicle height at the target position by controlling the operation of the compressor and the electromagnetic valve 83 of the supply / discharge device 80. .

Next, riding comfort control, steering stability control (hereinafter referred to as steering control) performed by the electromagnetic actuator control device 51, and vehicle height control performed by the vehicle height adjustment control device 52 will be described.
FIG. 4 shows a control routine for ride comfort control, steering stability control executed by the electromagnetic actuator control device 51, and a vehicle height control routine executed by the vehicle height adjustment control device 52. Is stored as a control program.

  The riding comfort control unit 51a of the electromagnetic actuator control device 51 is a logical operation unit that calculates the control amount of the electromagnetic actuator 30 so as to suppress the vertical vibration of the vehicle, and the vertical motion from the unsprung G sensor 62 and the unsprung G sensor 61. An acceleration signal is input for each wheel (S1), the acceleration signals are integrated (S2), and low-frequency vibration components that cause noise are cut by high-pass filtering (S3). The speed V2 is obtained (S4). Then, a sum (K1 · V1 + K2 · V2) of a value (K1 · V1) obtained by multiplying the unsprung speed V1 by the control gain K1 and a value (K2 · V2) obtained by multiplying the unsprung speed V2 by the control gain K2 is vibrated. Calculated as a suppression control amount (S5).

  On the other hand, the maneuverability control unit 51b of the electromagnetic actuator control device 51 inputs a lateral acceleration signal from the lateral G sensor 65 in order to detect a change in posture due to the turning motion of the vehicle, as shown in the middle part of FIG. (S6) A value (K3 · YG) obtained by multiplying the lateral acceleration YG by the control gain K3 is calculated as a roll suppression control amount (S7). The control amount in this case is the same on the front wheel side and the rear wheel side, but the sign is reversed on the left wheel side and the right wheel side. In other words, the control gain K3 on the left wheel side is set to -K3, so that the change in the posture of the vehicle (rolling motion) is suppressed.

Then, the sum of the vibration suppression control amount and the roll suppression control amount calculated for each wheel is calculated as the control amount of each electromagnetic actuator 30 (S8).
The amount of control is determined by energizing the electric motor 40 to generate a propulsive force (relative moving force between the inner cylinder 32 and the outer cylinder 31) applied to the outer cylinder 31 by expanding and contracting the ball screw mechanism 35 by the electric motor 40. And is calculated independently for each wheel W. Then, drive control of the electric motor 40 of the electromagnetic actuator 30 is performed with an energization amount corresponding to the calculated control amount (S9).
This control amount corresponds to the command value for the drive current of the electromagnetic actuator in the present invention.

  In this case, the switching elements SW11, SW12, SW21, SW22, SW31, and SW32 of the motor drive circuit 55 are opened and closed at a duty ratio corresponding to the control amount, but the regenerative current from the electric motor 40 is compared with the target energization amount. If the regenerative current is larger, the regenerative current flows to the battery 71 side, and conversely, if the regenerative current from the electric motor 40 is smaller than the target energization amount, the battery 71 is energized from the battery 71 by the difference.

  Further, the vehicle height adjustment control device 52 performs vehicle height control by PID control. That is, as shown in the lower part of FIG. 4, a preset target vehicle height H0 is read (S10), the actual vehicle height Hx is detected by the vehicle height sensor 63 (S13), and this target vehicle height H0 is detected. The deviation ΔH from the vehicle height Hx is multiplied by a control gain K4 (here, the control gains of the proportional term, differential term, and integral term are collectively referred to as K4) (S11), and the supply / discharge device according to the value K4 · ΔH The 80 electromagnetic valve 83 is opened and closed (S12).

  According to such a suspension control device 50, the impact received from the road surface by the air spring device 20 is absorbed to enhance the ride comfort and the vehicle body B is supported at a predetermined vehicle height position, while the vertical vibration of the air spring device 20 is prevented. The damping force with respect to the vertical vibration is adjusted so that good riding comfort can be obtained by the electromagnetic actuator 30. In addition, the electromagnetic actuator 30 is also expanded and contracted to suppress posture changes (roll motion) that occur when the vehicle turns.

By the way, when suppressing the posture change (rolling motion) that occurs when the vehicle turns, the electromagnetic actuator 30 needs a large driving force, and thus it is necessary to flow a large current through the electric motor 40. Therefore, when the vehicle turning state continues, a large current flows through the electric motor 40 due to roll suppression control (stability control), and the electric motor 40 and the motor drive circuit 55 are overheated or consumed. The power supply capability of the power supply device 70 is greatly reduced due to the increase in power.
The amount of current required for this roll suppression control is much larger than the amount of current required for normal vibration suppression control (riding comfort control).

In such a case, there is a possibility that the operation of the suspension control device 50 stops because an overheat prevention device (not shown) works or the power supply voltage Vx falls below the minimum operating voltage of the electronic circuit.
Therefore, in this embodiment, the electromagnetic actuator control device 51 gradually decreases the drive control amount (drive current command value of the electric motor) of the electromagnetic actuator 30 when it is estimated that it is difficult to continue the roll suppression control. I am doing so.
Hereinafter, the power consumption suppression process executed by the electromagnetic actuator control device 51 will be described.

FIG. 5 shows a power consumption suppression routine executed by the electromagnetic actuator control device 51 as the first embodiment, and is stored as a control program in a storage element (not shown) in the electromagnetic actuator control device 51.
This control routine is performed in parallel with the above-described riding comfort control and maneuverability control. The control routine is started by turning on an ignition switch (not shown) and is repeatedly executed at a predetermined short cycle.

  When the system of the electromagnetic actuator control device 51 is activated by turning on the ignition switch, first, the command value Ai to the electromagnetic actuator 30 is accumulated (S21). Since this control routine is repeatedly executed in a predetermined control cycle, the integrated value ΣAi of the command value Ai of the electromagnetic actuator 30 is 0 (zero) at the time of activation. This command value Ai corresponds to the command value of the drive current for driving the electric motor 40, and may be considered, for example, the control amount (K1 · V1 + K2 · V2 + K3 · YG) calculated in step S8 of FIG. .

  Next, it is determined whether or not roll suppression control is being performed (S22). If roll suppression control is not being performed (S22: NO), the process proceeds to step S23 to determine whether or not the flag F is F = 0. to decide. This flag F is set to F = 0 at the start of this control routine, and when the integrated value ΣAi of the command value Ai exceeds the reference value A0 and the roll suppression control gain K3 is reduced as will be described later. F = 1 is set, and when the roll suppression control gain K3 is further reduced to the minimum setting gain K3min, F = 2 is set. When the roll suppression control ends, F = 0 is set again. .

At the time of starting this control routine, since F = 0, this control routine is once ended as it is, and the process returns to step S21 again at a predetermined timing. In this way, the command value Ai of the electromagnetic actuator 30 is accumulated repeatedly. When the vehicle lateral acceleration YG is detected and the roll suppression control is started, the determination in step S22 is “YES”, and it is determined whether or not the integrated value ΣAi exceeds a preset reference value A0 (S24). ).
If ΣAi ≦ A0, it is estimated that the amount of power drawn from the power supply device 70 is below the reference and there is no risk of overheating of the electric motor 40 and the motor drive circuit 55, and this control routine is temporarily terminated.

If the integrated value ΣAi of the command value Ai of the electromagnetic actuator 30 exceeds the reference value A0 during the roll suppression control while repeating such processing, the amount of power drawn from the power supply device 70 exceeds the reference, and the electric motor 40 and the motor drive circuit 55 are presumed to be overheated or cause the power supply capability of the power supply device 70 to be reduced, the process proceeds to the next step S25, and the state of the flag F is confirmed. In this case, since F = 0 is set, the flag F is set to F = 1 (S26). Subsequently, the roll suppression control gain K3 is reduced by one step (S27), and the vibration suppression control gains K1, K2 are also reduced by one step (S28).
For this reason, the drive control amount of the electromagnetic actuator 30 in the riding comfort control and the stability control performed in parallel with this control routine is reduced by one step.

Subsequently, it is determined whether or not the roll suppression control gain K3 has decreased to a preset minimum setting gain K3min (S29). The minimum set gain K3min is set to a value that is reached when the roll suppression control gain K3 is reduced by a predetermined number of times. Therefore, the faster the control cycle of this control routine is, the smaller the amount of reduction of the control gain is and the greater the predetermined number of times until the minimum set gain K3min is reached.
Therefore, at the beginning of reducing the roll suppression control gain K3, K3> K3min (S29: NO) ", the control routine is temporarily exited, and the same processing is repeated again.

Therefore, during the roll suppression control, the roll suppression control gain K3 and the vibration suppression control gains K1 and K2 are gradually reduced. When the roll suppression control is continued to some extent and the roll suppression control gain K3 reaches the minimum set gain K3min, the flag F is set to F = 2 (S30).
For this reason, when the roll suppression control is further continued, the process of steps S27 and S28 is skipped by the determination in step S25, and the reduction process of the control gains K1, K2, and K3 is not performed.

  Therefore, thereafter, the electromagnetic actuator 30 is driven and controlled by the control amount calculated with the minimum set gain K3min, and roll suppression is performed. Further, if riding comfort control is being performed at this time, the control amount calculated with the reduced control gains K1 and K2 is added.

  When the vehicle lateral acceleration YG is no longer detected and the roll suppression control ends, the determination in step S22 is “NO”, and it is determined in step S23 whether the flag F is F = 0. In this case, since the flag F is set to F = 1 or F = 2, the process proceeds to step S31, and the roll suppression control gain K3 and the vibration suppression control gains K1 and K2 are returned to their initial values. That is, it is estimated that the end of the roll suppression control has eliminated the possibility of overheating of the electric motor 40 and the motor drive circuit 55 and the possibility of a decrease in power supply capability of the power supply device 70, and the control gains K1, K2, and K3 are set to the initial values. The desired driving force by the electromagnetic actuator 30 is obtained. In step S33, the flag F is set to F = 0, the control routine is exited, and the above-described processing is repeated.

  According to the power consumption suppression routine described above, as shown in the timing chart of FIG. 6, when roll suppression control is started at time t <b> 1, calculation is performed with a control gain K <b> 3 set in advance for the electromagnetic actuator 30. Control command to be output. At time t2, when the integrated value ΣAi of the command value Ai for driving the electromagnetic actuator 30 reaches the reference value A0, the electric motor 40 and the motor drive circuit 55 may be overheated, and the power supply capability of the power supply device 70 is reduced. The roll suppression control gain K3 is gradually reduced. In this case, the vibration suppression control gains K1 and K2 are also gradually reduced.

Accordingly, the energization amount to the electric motor 40 is gradually reduced. In this case, the roll amount increases because the roll suppression degree decreases, but the increase degree is moderate, so that the driver does not feel uncomfortable or uneasy.
When the roll suppression control gain K3 decreases to the minimum set gain K3min at time t3, the control gains K1, K2, and K3 are held at those values, and the command value Ai to the electromagnetic actuator 30 is not reduced. Therefore, roll suppression control is performed with a minimum amount of power. Thereafter, when the lateral acceleration YG is not detected at time t4 and the roll suppression control is finished, the command value Ai to the electromagnetic actuator 30 becomes zero. The vehicle naturally returns to the horizontal state.

  As described above, according to the power consumption suppression process of the first embodiment, the overheating of the electric motor 40 and the motor drive circuit 55 is estimated from the integrated value of the command value of the electromagnetic actuator 30 (overheating if the roll suppression control is continued further. Estimation) and a decrease in power supply capability of the power supply device 70 (estimation that the power supply capability decreases when the roll suppression control continues further), and based on this estimation, control gains K1, K2, Since K3 is gradually reduced to reduce the energization amount of the electric motor 40, it is possible to prevent overheating and suppress a decrease in power supply capability.

Accordingly, the overheat prevention device provided in the circuit is activated during the roll suppression control, or the operation of the suspension control device 50 is suddenly stopped due to the power supply voltage Vx being lower than the minimum operating voltage of the electronic circuit. There is no. In addition, since the degree of roll suppression is gradually weakened, the driver does not feel uncomfortable or uneasy.
Note that the processing unit that estimates that the roll suppression control cannot be continued from the command integrated value ΣAi of the electromagnetic actuator 30 in steps S21 and S24 of the present control routine corresponds to the uncontinuable state detecting means of the present invention.

Next, the power consumption suppression control process as the second embodiment will be described.
FIG. 7 shows a power consumption suppression routine executed by the suspension control device 50 as the second embodiment, and is stored as a control program in a storage element (not shown) in the suspension control device 50.

Since this control routine is obtained by further adding the processes of step S40 and step S41 to the power consumption suppression control routine of the first embodiment, only the process will be described, and other common processes will be described. The same step number is attached to and the description is omitted.
When the integrated value ΣAi of the command value Ai for driving the electromagnetic actuator 30 reaches the reference value A0 during the roll suppression control, the roll suppression control gain K3 is reduced, so that the force for suppressing the roll decreases and the vehicle rolls. . Therefore, in the second embodiment, while the roll suppression control gain K3 is being reduced in step S17, the vehicle height adjustment control device 52 uses the air spring device 20 as shown in the timing chart of FIG. Helps suppress roll movement.

For example, the vehicle height adjustment control device 52 receives the lateral acceleration signal from the lateral G sensor 65, and expands one of the left and right air spring devices 20 and contracts the other in accordance with the lateral acceleration YG. To change. If the vehicle is in a roll motion that tilts to the left, the air spring device 20 of the left wheel W is extended to raise the left vehicle height, and the air spring device 20 of the right wheel W is compressed to lower the right vehicle height.
The expansion and contraction of the air spring device 20 is performed by adjusting the pressure in the air chamber 24 by opening / closing control of an electromagnetic valve 83 provided in the air supply / exhaust pipe 81. In this case, the vehicle height adjustment command value to the air spring device 20 is gradually increased in accordance with the speed at which the roll suppression control gain K3 of the electromagnetic actuator 30 is gradually decreased.

When the roll suppression control gain K3 reaches the minimum set gain K3min (FIG. 8: time t3), the vehicle height adjustment command value is held at that value, and the roll suppression control ends (FIG. 8: time). At t4), the vehicle is quickly returned to the initial vehicle height value (S41).
As a result, as shown in FIG. 8, the roll amount of the vehicle can be suppressed to a small value as compared with the case where the air spring device 20 does not assist the roll suppression (shown by a broken line).
Therefore, since the roll restraint control of the vehicle is assisted using the vehicle height adjustment function of the air spring device 20 using the air pressure, the roll restraint ability can be improved without substantially increasing the power consumption.
Of course, the effect of 1st Embodiment is also show | played.

Next, the power consumption suppression control process as the third embodiment will be described.
FIG. 9 shows a power consumption suppression routine executed by the suspension control device 50 as the third embodiment, and is stored as a control program in a storage element (not shown) in the suspension control device 50.

  In the power consumption suppression control routine of the first embodiment and the second embodiment described above, when the command value Ai of the electromagnetic actuator 30 is constantly integrated, and the integrated value ΣAi exceeds the reference value A0, roll suppression is performed. In this third embodiment, the state of the power supply device 70 is changed to the estimation based on the integrated value ΣAi, although it is assumed that the control cannot be continued and the control gain of the electromagnetic actuator 30 is gradually decreased. It is directly detected to estimate whether roll suppression control can be continued.

That is, in the power consumption suppression control routine of the third embodiment, instead of the processes of steps S21 and S24 in the first and second embodiments, the processes of steps S50 and S51 are performed as shown in FIG.
In the following description, the same processes as those in the first and second embodiments are denoted by the same step numbers in the drawings, and the description thereof is omitted.

In this control routine, the voltage of the power supply device 70 (power supply voltage Vx) is detected during the roll suppression control (S50). The electromagnetic actuator control device 51 converts the output voltage of the power supply device 70 into a digital quantity by an A / D converter (not shown) and measures the voltage.
The power supply voltage Vx is substantially proportional to the power supply capability of the power supply device 70, and the power supply capability increases as the power supply voltage Vx increases.
Then, it is determined whether or not the detected power supply voltage Vx is lower than the reference voltage V0 (S51). If Vx ≧ V0, it is estimated that the power supply capability of the power supply device 70 is sufficient, and this control routine is temporarily executed as it is. finish.

  On the other hand, when the determination in step S51 is “YES”, that is, when the power supply voltage Vx is lower than the reference voltage V0, the power consumption from the power supply device 70 is excessive, and the roll suppression control cannot be continued as it is. It is estimated that this is possible, and the process proceeds to the process from step S25 described above.

For example, when the power supply voltage Vx decreases to a predetermined value lower than the reference voltage V0, the power supply voltage supplied to the electronic circuit (for example, the microcomputer) in the suspension control device 50 may be lower than the minimum operation voltage required for the operation. is there. In this case, the operation of the suspension control device 50 stops.
Further, when the power is consumed so that the power supply voltage Vx is lower than the reference voltage V0, the electric motor 40 and the motor drive circuit 55 may be overheated.

  Therefore, if the power supply voltage Vx falls below the reference voltage V0 during the roll suppression control, it is estimated that the roll suppression control cannot be continued, and the above-described gradual reduction processing of the control gains K1, K2, K3 (S27) , S28) and assisting the roll suppression control by the air spring device 20 (S40). Then, when the roll suppression control is finished, the control gains K1, K2, K3 and the vehicle height control value are returned to the initial values (S31, S32, S41).

According to the power consumption suppression control routine of the third embodiment described above, in order to suppress a decrease in the power supply capability of the power supply device 70, the problem that the suspension control device 50 stops suddenly during the roll suppression control is prevented. can do. In addition, it is possible to prevent the operation of other vehicle control devices that commonly use the power supply device 70 from being stopped.
Further, since the control gain of the electromagnetic actuator 30 is gradually reduced, the vehicle posture does not change suddenly, and the driver does not feel uncomfortable or uneasy.
Furthermore, overheating of the electric motor 40 and the motor drive circuit 55 can be prevented.

Although the suspension device of the present embodiment has been described above, 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 present embodiment, as the electromagnetic actuator, a rotation-linear motion conversion mechanism that rotates the ball screw 36 by the electric motor 40 and moves the ball screw nut 39 up and down in the axial direction is used. An electromagnetic actuator using a type motor may be adopted. For example, this direct acting motor is provided with an electromagnetic coil on the inner peripheral surface of the outer cylinder, and a permanent magnet facing the electromagnetic coil is disposed on the outer peripheral surface of the inner cylinder, and the electromagnetic coil is energized. Axial thrust is generated between the cylinder and the electromotive force is generated in the electromagnetic coil by the axial relative movement of the outer cylinder with respect to the inner cylinder, and a damping force is generated by energizing the electromagnetic coil and generating power. It is.

In the present embodiment, the vibration suppression control gains K1 and K2 are also reduced together with the reduction of the roll suppression control gain K3. However, for example, only the reduction of the roll suppression control gain K3 may be used. It is not limited to the one that reduces the above.
In the present embodiment, the decrease in the power supply capability of the power supply device 70 is estimated by the power supply voltage Vx. For example, an ammeter is provided on the power supply line, and the integrated value of the current drawn from the power supply device 70 Therefore, a decrease in power supply capability may be estimated, and an estimation method suitable for the type of power supply device 70 can be employed.
The posture change detection means is not limited to the lateral acceleration sensor, and a yaw rate sensor, a steering angle sensor, or the like can be used.

1 is a system configuration diagram of a suspension device according to an embodiment of the present invention. It is sectional drawing showing schematic structure of a suspension main body. It is a functional block diagram of a suspension control device. It is a flowchart showing a control routine and a vehicle height control routine of riding comfort control, steering stability control. It is a flowchart showing the power consumption suppression control routine of 1st Embodiment. It is a graph showing transition of an electromagnetic actuator command value and a roll amount. It is a flowchart showing the power consumption suppression control routine of 2nd Embodiment. It is a graph showing transition of an electromagnetic actuator command value, a vehicle height adjustment command value, and a roll amount. It is a flowchart showing the power consumption suppression control routine of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Suspension main body, 20 ... Air spring apparatus, 30 ... Electromagnetic actuator, 40 ... Electric motor, 50 ... Suspension control apparatus, 51 ... Electromagnetic actuator control apparatus, 51a ... Riding comfort control part, 51b ... Stability control part, 52 ... height adjustment control device, 55 ... motor drive circuit.

Claims (4)

An electromagnetic force is provided between the wheels and the vehicle body, receives electromagnetic force in the vertical direction of the wheels, and generates an electromagnetic force when the vehicle body and the wheels approach or separate from each other. An electromagnetic actuator for generating a propulsive force that approaches or separates from the wheel;
Posture change detecting means for detecting posture change due to turning motion of the vehicle;
In a suspension apparatus comprising: an actuator control unit that calculates a drive current command value of the electromagnetic actuator so as to suppress a change in posture of the vehicle and drives and controls the electromagnetic actuator;
A continuation impossible state amount detecting means for detecting a predetermined state amount that is estimated to be impossible to continue posture change suppression control by the electromagnetic actuator;
The actuator control means is configured to detect the electromagnetic wave when a predetermined state quantity that is estimated to be impossible to continue the attitude change suppression control is detected by the continuation impossible condition quantity detection means during the vehicle attitude change suppression control. A suspension device characterized by gradually reducing a command value of an actuator drive current.   The non-continuable state amount detecting means calculates a cumulative amount of a command value of a drive current supplied to the electromagnetic actuator, and continues the posture change suppression control when the cumulative amount of the command value reaches a predetermined cumulative amount. The suspension device according to claim 1, wherein the suspension device is estimated to be impossible.   The continuation disabling state amount detecting means detects a state of the in-vehicle power supply device, and estimates that the posture change suppression control cannot be continued when a predetermined power supply capability decrease is detected. The suspension device according to claim 1. The vehicle is provided with the electromagnetic actuator between the wheel and the vehicle body, and includes a vehicle height adjusting device that can extend and contract in the vertical direction.
When it is estimated that the posture change suppression control cannot be continued and the command value of the drive current supplied to the electromagnetic actuator is gradually reduced, the vehicle height adjustment device assists the vehicle posture change suppression control. The suspension device according to any one of claims 1 to 3, wherein the suspension device is characterized in that:

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