JP4275551B2 - Self-diagnosis device for active suspension - Google Patents

Description

  The present invention relates to a self-diagnosis device for an active suspension.

  In general, a suspension is known in which a hydraulic shock absorber is interposed between a vehicle body and an axle in parallel with a suspension spring. This suspension suspends the vehicle body and attenuates input such as vibration from a road surface. The ride comfort and controllability are improved, or the vehicle height is kept constant by suppressing the displacement of the vehicle body. This hydraulic shock absorber is advantageous in that a high damping force can be obtained, but on the other hand, oil is required, and a seal mechanism and a complicated valve mechanism for preventing leakage of the oil are required.

  Therefore, recently, a new suspension device that does not require oil, air, power supply, etc. has been studied and proposed (see Patent Document 1 and Non-Patent Document 1).

  The basic structure of this suspension device is composed of a screw shaft that is rotatably engaged with a ball screw nut, and a motor that is connected to one end of the screw shaft and short-circuits the electrode. The screw shaft and the motor shaft rotate, and the damping force that suppresses the linear motion of the ball screw nut with the torque opposite to the rotation direction of the shaft and screw shaft by the induced electromotive force generated by the rotation of the shaft. It is intended to be used as

Further, in this suspension device, if an electric current is supplied to the motor, it can be used as an actuator, so that it is desired to be used as an active suspension.
JP 2003-227543 A (paragraph number 0023, FIG. 1) Suematsu, Suda, "Study on Electromagnetic Suspension in Automobile", Japan Society for Automotive Engineers, Preprint of Academic Lecture, 2000, No4-00

  That is, in the active suspension, in order to efficiently suppress the vibration of the vehicle body side member, the control force generated as the actuator applies a forced external force to the vehicle body side member to suppress the vibration, and the shock absorber is the vehicle body. It is necessary to adjust the damping force according to the state of vibration of the side member.

  Therefore, in such an active suspension, control force and damping force adjustment are important for vibration suppression control, and if this control force adjustment and damping force adjustment are not performed correctly, it functions as an active suspension. It may not be possible.

  Therefore, an object of the present invention is to provide a self-diagnosis device for an active suspension.

In order to achieve the above-described object, a first problem solving means is an active suspension self-diagnosis device that is interposed between a vehicle body side member and an axle side member of a vehicle and is capable of adjusting a generated control force. The suspension includes a motion conversion mechanism that converts relative motion between the vehicle body side member and the axle side member into rotational motion, and a motor to which the rotational motion is transmitted, and the electromagnetic force generated in the motor is subjected to electromagnetic force generated in the motor. A suspension device that is used as a control force that suppresses relative movement between the motor shaft and the rotation angle of the motor shaft with respect to changes in the current value or voltage value supplied to the motor or a vehicle body side member and an axle side member Create a graph showing the change in relative displacement, and the rotation angle of the motor shaft relative to the current value or voltage value supplied to the motor. Ku is characterized by performing the determination suspension system is normal by comparing the normal graph showing the normal relationship between the relative displacement of the vehicle body-side member and the axle-side member.

The second problem solving means determines that the suspension device is normal when the difference between the graph created during the self-diagnosis and the normal graph is within a predetermined standard in the first problem solving means. .

The third problem solving means is characterized in that, in the first and second problem solving means, a normal graph is corrected based on the vehicle body weight change amount at the time of self-diagnosis.

The fourth problem-solving means is any one of the first to third problem-solving means, wherein the rotation angle of the shaft of the motor or the relative displacement between the vehicle body side member and the axle side member or the vehicle side Perform self-diagnosis based on the relative speed between the member and the axle side member, the relative acceleration between the body side member and the axle side member, the absolute displacement of the body side member, the absolute speed of the body side member, or the absolute acceleration of the body side member. It is characterized by.

The fifth problem-solving means is the fourth problem-solving means, in which the rotation angle of the motor shaft or the relative displacement between the vehicle body side member and the axle side member or the vehicle body side member and the axle side member between The suspension device is normal when the relative speed or the relative acceleration between the vehicle body side member and the axle side member, the absolute displacement of the vehicle body side member, the absolute speed of the vehicle body side member, or the absolute acceleration of the vehicle body side member is within a predetermined reference. Make a decision.

The sixth problem-solving means is the fifth problem-solving means according to the fifth problem-solving means, the rotation angle of the shaft of the motor or the relative displacement between the vehicle body side member and the axle side member or the vehicle body side member and the axle over time after the vehicle body vibration during self-diagnosis. create a graph showing the absolute change in acceleration in the absolute speed or the vehicle body side member of the absolute displacement or the vehicle body side member of the relative acceleration or the body side member of the relative speed or the vehicle body-side member and the axle-side member of the side members, and this graph, The rotation angle of the motor shaft over time after vibration of the vehicle body, the relative displacement of the vehicle body side member and the axle side member, the relative speed of the vehicle body side member and the axle side member, the relative speed of the vehicle body side member and the axle side member, or the vehicle body side Compared with a graph showing normal changes in the absolute displacement of the member, the absolute speed of the vehicle body side member, or the absolute acceleration of the vehicle body side member, Device performs a determination is normal.

The seventh problem-solving means is the sixth problem-solving means, in which a current or voltage is supplied to the motor during self-diagnosis to cancel the rotation angle of the shaft of the motor according to the change in the weight of the vehicle body and It is characterized by generating a control force that cancels out the change in the sprung vibration frequency and the change in the damping rate due to the change.

  According to the invention of each claim, it is possible to accurately determine whether or not the actuator function of the active suspension functions normally.

  In addition, if a self-diagnosis is performed when the vehicle is stopped, the abnormality of the active suspension can be detected and the passenger can be notified before the vehicle starts, ensuring the safety of the passenger. be able to.

Furthermore, when detecting the active suspension abnormality, to function as a normal suspension by stopping the active control, it is possible to also ensure the safety of the passenger in this respect, the fear of hindering the vehicle running It can be avoided.

  Further, when the abnormality of the active suspension is only the change in the spring constant of the suspension spring for suspending the vehicle, it is possible to perform active control in accordance with the change in the spring constant.

In addition, a graph showing the normal relationship between the rotation angle of the motor shaft relative to the current value or voltage value supplied to the motor or the relative displacement between the vehicle body side member and the axle side member and the motor created during self-diagnosis By comparing the rotation angle of the motor shaft with respect to the change in the current value or voltage value or the graph showing the change in relative displacement of the vehicle body side member and the axle side member, it is determined whether the vehicle is normal or not. Self-diagnosis corresponding to the above is possible, and an abnormality can be accurately detected.

Further, according to the invention of claim 3 , the normal relationship between the rotation angle of the shaft of the motor or the relative displacement between the vehicle body side member and the axle side member with respect to the current value or voltage value supplied to the motor due to the change in the vehicle body weight is shown. by correcting the graph, compared with the graph showing the change in the relative displacement of the rotation angle or the vehicle body-side member and the axle-side member of the motor shaft with respect to the change in the current value or voltage value is supplied to the motor which is created during the self-diagnosis Therefore, it is possible to accurately detect the abnormality regardless of the change in the weight of the vehicle body.

According to the inventions of claims 4 to 7 , it is possible to determine whether the vibration suppression characteristic of the active suspension is normal or abnormal, and it is possible to accurately determine whether or not the active suspension functions normally.

  Furthermore, since the self-diagnosis of the actuator function of the suspension device and the self-diagnosis of the vibration suppression characteristics of the active suspension can be performed, so to speak, it is possible to accurately determine whether the active suspension is normal or not by performing a double check. It is possible to ensure the safety of the passenger and to avoid the risk of hindering vehicle travel.

Then, billing according to the invention of claim 6 and 7, to create a graph showing the change in the rotational angle of the motor shaft due to the time course of the body pressure Funochi upon self, this and graphs, the body pressure Funochi time Compared with graphs showing normal changes in motor shaft rotation angle over time, the suspension system is judged to be normal, enabling self-diagnosis for each vehicle and accurately detecting abnormalities. can do.

According to the seventh aspect of the present invention, at the time of self-diagnosis, current or voltage is supplied to the motor to cancel the rotation angle of the motor shaft associated with the vehicle body weight change amount and Since a control force that cancels the vibration frequency change and damping rate change is generated, the vehicle vibration status at the time of graph creation showing the change in the rotation angle of the motor shaft over time after normal vehicle vibration and the vehicle body at the self-diagnosis The vibration state can be made the same, that is, the vehicle body can be vibrated under the same condition regardless of the vehicle body weight change. And since the above normal graph can be compared with the graph showing the change in the rotation angle of the motor shaft over time obtained after the vehicle body vibration obtained under the same conditions, the abnormality can be accurately determined regardless of the vehicle body weight change. Can be detected.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a suspension device according to an embodiment of the present invention. FIG. 2 is a diagram showing a state in which the active suspension is applied to a vehicle. FIG. 3 is a flowchart showing a procedure in which the self-diagnosis device performs a self-diagnosis on the actuator function of the suspension device. FIG. 4 is a diagram showing the relationship between the current and the rotation angle of the shaft of the motor. FIG. 5 is a diagram showing the relationship between the offset current and the rotation angle of the shaft of the motor. FIG. 6 is a conceptual diagram showing an example of the stroke position detecting means. FIG. 7 is a flowchart showing a procedure for the self-diagnosis apparatus to obtain a vibration suppression characteristic graph. FIG. 8 is a vibration suppression characteristic graph showing the relationship between the rotation angle and time. FIG. 9 is a flowchart illustrating a procedure in which the self-diagnosis device performs self-diagnosis on the vibration suppression characteristics of the suspension device. FIG. 10 is a longitudinal sectional view of a suspension device according to another embodiment.

 As shown in FIG. 1, the suspension device according to the present embodiment basically has a motion conversion composed of a ball screw nut 4 and a screw shaft 3 that is rotatably screwed into the ball screw nut 4. The mechanism and the motor 1 are configured, and the upper end of the screw shaft 3 is connected to the shaft 1a of the motor 1, and the torque generated by the motor 1 is adjusted by supplying current to the motor 1, and the torque is transmitted to the screw shaft 3. The vertical movement of the ball screw nut 4 in FIG. 1 when the suspension device expands and contracts can be controlled.

 The detailed structure will be described below. The motor 1 is installed in a bottomed cylindrical outer cylinder 2, and the shaft 1 a of the motor 1 is rotatably inserted into the outer cylinder 2 via ball bearings 9, 10, and 11. The shaft 1 a is connected to the screw shaft 3. In the figure, the screw shaft 3 and the shaft 1a are connected as separate members. However, the screw shaft 3 and the shaft 1a may be integrally formed. A bracket 20 for attaching the suspension device to the vehicle is provided at the upper end of the outer cylinder 2 in FIG.

The motor 1 is attached so as to face the magnets 7, 7 on the inner periphery of the outer cylinder 2, the shaft 1 a connected to the screw shaft 3, the magnets 7, 7 attached to the outer periphery of the shaft 1 a. In this case, the outer cylinder 2 serves as a frame for the motor 1. Each electrode (not shown) of the motor 1 is connected to the ECU 30 as shown in FIG. 2 to supply current from the ECU 30 to the motor 1 so that the motor 1 can generate torque caused by electromagnetic force. Yes, it is set to obtain a desired damping force. In addition, this brushless motor is equipped with a Hall element H as a rotor position detecting means, and this Hall element H is connected to a rotation logic of a drive circuit, which will be described later. (Rotational angle, angular velocity, etc.) can be grasped. In place of the Hall element H, a magnetic sensor, an optical sensor, or the like may be mounted. When using a motor that does not have position detection means, such as a DC brush motor, it may be preferable to provide position detection means for controlling the suspension device. This will be described later. Further, if a Hall element as a position detecting means is taken as an example, it is necessary to energize the element from an external power source. However, the bracket 20 side is attached to the vehicle body side of the vehicle. If an electric wire (not shown) for energization is connected to the element via the bracket 20 and current is supplied, the electric wire extending from the upper end side of the bracket 20 in FIG. When connecting to the control device and the control circuit, it becomes easy and the electric wire is accommodated in the vehicle body, so that the chance of damaging the electric wire can be reduced. Further, since electric power is generated by the rotation of the ball screw nut 4 without using an external power source, the current generated by the induced electromotive force is supplied to the Hall element or stored in an external battery. Current may be supplied from a battery. Incidentally, the position detecting means is always energized and is connected to an ECU 30 or the like which will be described later, so that an accurate vehicle height can be detected. In this embodiment, the coil 6 is attached to the outer cylinder 2 side and the magnets 7 and 7 are attached to the shaft 1a side. However, the coil 6 is attached to the shaft 1a side and the magnets 7 and 7 are attached.
May be attached to the outer cylinder 2 side. In the present embodiment, the motor 1 is a brushless motor, but various motors such as a DC motor, an AC motor, an induction motor, and the like can be used as long as they can be used as an electromagnetic force generation source.

  The screw shaft 3 connected to the shaft 1a is provided with a screw groove 3a on the outer periphery thereof, and is inserted into a bottomed cylindrical inner cylinder 5 slidably inserted into the outer cylinder 2, The ball screw nut 4 fitted in the inner cylinder 5 is rotatably screwed. That is, in this embodiment, the screw shaft 3 and the ball screw nut 4 constitute a motion conversion mechanism, and the relative linear motion in the axial direction of the ball screw nut 4 and the screw shaft 3 is the same as that of the screw shaft 3. Converted to rotational motion. Here, although the structure of the ball screw nut 4 is not particularly illustrated, for example, a spiral ball holding portion is provided on the inner periphery of the ball screw nut 4 so as to coincide with the spiral screw groove 3 a of the screw shaft 3. A large number of balls are arranged in the holding portion, and a passage is provided in the ball screw nut 4 to communicate both ends of the helical holding portion so that the balls can circulate. When the screw shaft 3 is screwed into the ball screw nut 4, the ball of the ball screw nut 4 is fitted into the spiral screw groove 3 a of the screw shaft 3, and the screw shaft 3 is rotated. Accordingly, the ball itself is rotated by the frictional force with the screw groove 3a of the screw shaft 3, so that a smooth operation is possible compared to a mechanism such as a rack and pinion. However, the motion conversion mechanism is configured by a rack and pinion, and the pinion Of motor 1 It may be linked to Yafuto 1a.

  As described above, the screw shaft 3 is rotatably engaged with the ball screw nut 4 along the screw groove 3a. When the ball screw nut 4 moves linearly in the vertical direction in FIG. Since the rotational movement of the screw nut 4 is restricted by, for example, the inner cylinder 5 fixed to the vehicle body or the axle side, the screw shaft 3 is forcibly driven to rotate. That is, the linear motion of the ball screw nut 4 is converted into the rotational motion of the screw shaft 3 by the above mechanism. When the ball screw nut 4 moves downward in FIG. 1 and the suspension device is fully extended, the cushion member 15 provided at the lower end of the screw shaft 3 in FIG. The screw shaft 3 is prevented from coming out of the ball screw nut 4 by coming into contact with the lower end, and the shock at the time of full extension is alleviated. At the time of maximum compression, the screw shaft 3 is the bottom of the inner cylinder 5 described later. To reduce the impact.

 A dust seal (not shown) is provided between the outer cylinder 2 and the inner cylinder 5, thereby preventing dust, dust, rainwater, etc. from entering the space formed by the outer cylinder 2 and the inner cylinder 5. Has been. Incidentally, although the inner cylinder 5 is slidably inserted into the outer cylinder 2, an annular bearing may be provided between the outer cylinder 2 and the inner cylinder 5. In this case, it is possible to prevent the risk that the inner periphery of the lower end portion of the outer cylinder 2 bites the outer peripheral surface of the inner cylinder 5 and the sealing performance between the outer cylinder 2 and the inner cylinder 5 deteriorates.

 Further, since the inner cylinder 5 is slidably inserted into the outer cylinder 2, the axial movement of the screw shaft 3 with respect to the inner cylinder 5 and the ball screw nut 4 is prevented, whereby the ball screw nut 4. It is possible to prevent a load from being concentrated on a part of the balls (not shown), and to avoid a situation in which the ball or the screw groove 3a of the screw shaft 3 is damaged. Further, since the ball or the screw groove 3a of the screw shaft 3 can be prevented from being damaged, the smoothness of each operation of the rotation of the screw shaft 3 and the ball screw nut 4 or the movement of the suspension device in the expansion / contraction direction can be maintained. Since the smoothness of each operation can be maintained, the function as a suspension device is not impaired, and the failure of the suspension device can be prevented.

 Further, an eye bracket 21 is provided at the lower end of the inner cylinder 5 in FIG. 1, and the eye bracket 21 and the bracket 20 provided at the upper end of the outer cylinder 2 in FIG. A suspension device can be interposed between the vehicle body and the axle.

  The suspension device configured as described above expands and contracts, that is, when the inner cylinder 5 moves in the vertical direction in FIG. 1 with respect to the outer cylinder 2, the ball screw nut 4 connected to the inner cylinder 5 also has a shaft. A linear motion in the direction, that is, a linear motion in the vertical direction in FIG. This linear motion of the ball screw nut 4 is converted into a rotational motion of the screw shaft 3 by the ball screw mechanism of the ball screw nut 4 and the screw shaft 3.

  When the screw shaft 3 exhibits a rotational motion, the shaft 1a also rotates. Then, the coil 6 in the motor 1 crosses the magnetic fields of the magnets 7 and 7, and an induced electromotive force is generated in the coil 6, and the motor 1 resists the rotation of the shaft 1a caused by the induced electromotive force. Generate torque. The torque against the rotation of the shaft 1a suppresses the rotation of the screw shaft 3 and the linear motion of the ball screw nut 4 because the shaft 1a is connected to the screw shaft 3. The sum of the current flowing in the coil 6 caused by the induced electromotive force generated by the rotation of the shaft 1a with the rotation of the screw shaft 3 and the current supplied from the ECU 30 (described later) to which the motor 1 is connected. An electromagnetic force is generated, and the suspension device generates a damping force commensurate with the electromagnetic force. The generated damping force of the suspension device can be adjusted by supplying current from the ECU 30 and is supplied to the motor 1. It can also be used as an actuator by adjusting the amount of current.

  Therefore, the action of suppressing the rotational movement of the shaft 1a of the motor 1 works to suppress the linear movement of the ball screw nut 4, and thus acts as a damping force that suppresses the linear movement of the ball screw nut 4. Absorbs and relaxes energy. Further, here, if the amount of current supplied to the motor 1 is adjusted, the torque generated by the motor 1 not only acts as a damping force but also as a force in the direction of increasing the expansion / contraction with respect to the expansion / contraction of the suspension device. In contrast, the suspension device can be actively expanded and contracted, and the expansion and contraction of the suspension device can be freely controlled.

  As described above, through a series of operations, the suspension device can not only generate a damping force but also function as an actuator. Therefore, unlike the conventional active suspension, it is not necessary to mount an actuator in addition to the shock absorber, and it is not necessary to mount a hydraulic power source or the like for driving the actuator. As well as improving the performance, the weight can be reduced compared to the conventional active suspension.

  In addition, in the conventional hydraulic suspension device, it is indispensable to mount the actuator and the hydraulic power source as described above, and it may be impossible to attach to the existing vehicle, so-called retrofitting due to the mounting space. Since the suspension device of this form is slim and space-saving compared to the conventional suspension device, it can be retrofitted to an existing vehicle.

 Next, a state in which this suspension device is applied to an actual vehicle will be described. Each suspension device D1, D2, D3, D4 configured as described above is, for example, a four-wheeled vehicle, as shown in FIG. , B4 and the axle side members S1, S2, S3, S4, and suspension springs K1, K2, K3, K4 such as metal springs and air springs in parallel with the suspension devices D1, D2, D3, D4 Intervened. In this case, the outer cylinder 2 of the suspension devices D1, D2, D3, and D4 is attached to the vehicle body side, and the inner cylinder 5 is attached to the axle side.

Each motor 1 and each Hall element H of each suspension device D1, D2, D3, D4 is connected to an ECU 30 that is a controller for the suspension device. The ECU 30 further includes an alarm device 70 and a coil 6 of each motor 1. Is connected to a current sensor (not shown) for detecting a current i1 flowing through The ECU 30 is used for self-diagnosis of the suspension devices D1, D2, D3, and D4. The ECU 30 includes a current i1 detected by a current sensor and a shaft 1a of a motor 1 that includes a Hall voltage detected by a Hall element H. A graph showing the relationship between the rotational position and the rotation angle θ1 of the shaft 1a, and a graph showing the current i1 and the rotation angle θ1 supplied to each motor 1 of each suspension device D1, D2, D3, D4 in a normal state comparing actually from divergence situation with the relationship between the current i1 that the supply and the relationship between the rotation angle .theta.1, and the rotation angle .theta.1 and current i1 in normal condition shown in the graph, the active suspension If it is possible to determine whether the suspension device D1, D2, D3, D4 is abnormal or not and can output a control signal to the alarm device Specifically, for example, a current sensor or a voltage sensor, an amplifier for amplifying the shaft 1a rotation position signal and the current sensor or voltage sensor signal, which are composed of the Hall voltage detected by each Hall element H, and an analog Computer system and motor 1 comprising a converter for converting a signal into a digital signal, a band-pass filter for cutting low frequency and high frequency components, a storage device such as a CPU and ROM, a RAM, a crystal oscillator, and a bus line connecting them. And a control signal output procedure such as current supply or voltage supply as a program showing the normal state and the self-diagnosis calculation processing procedure used for computation during self-diagnosis processing. A well-known system may be used which is stored in advance in a ROM or other storage device. In the case of the motor 1 as a brushless motor, the drive circuit includes, for example, a PWM circuit connected to a voltage source, a base drive circuit connected to the PWM circuit, a transistor inverter connected to the base drive circuit, and a hall A well-known device composed of a rotation logic to which the element H is connected can be used, and other devices that can adjust the amount of current according to the type of the motor can be used. The alarm device may be one that generates an alarm sound by supplying current, or may be a monitor for a navigation system mounted on a vehicle. The ECU 30 is connected to a select switch (not shown). The select switch has two positions, a self-diagnosis processing position and a self-diagnosis processing cancel position. By operating it, it is possible to selectively switch to any position, and when taking a self-diagnosis processing position, it can be received as a signal consisting of current and voltage that the position has been selected on the ECU 30 side. It is like that. The ECU 30 of the present embodiment is capable of active control by supplying current or voltage to the motors 1 of the suspension devices D1, D2, D3, and D4. Although not described in detail, the ECU 30 performs active control. The control processing procedure is also stored in the storage device.

Here, the graph stored in advance in the storage device of the ECU 30 is created, for example, according to the following procedure. Here, when the current i1 is supplied to each motor 1, when the current i1 takes a positive value, the force F is applied in the direction in which each motor 1 is rotated forward to extend the suspension devices D1, D2, D3, D4. On the other hand, if the current i1 takes a negative value, the force F is generated in the direction in which the motors 1 are reversed and the suspension devices D1, D2, D3, D4 are contracted.

  First, the ECU 30 supplies the motor 1 of the suspension devices D1, D2, D3, and D4 while gradually increasing the current value of the current i1 from zero to extend the suspension devices D1, D2, D3, and D4. Is recognized from the signal from the current sensor, and the rotational position of the shaft 1a of the motor 1 when the current i1 is zero from the rotational position of the shaft 1a detected by each Hall element H is used as a reference. The rotation angle θ1 up to the current rotation position of the shaft 1a is calculated, the relationship between the current i1 and the rotation angle θ1 is graphed, and this is stored in the ECU 30 as a normal value. Further, the ECU 30 supplies the motor 1 of the suspension devices D1, D2, D3, and D4 while gradually decreasing the current value of the current i1 from zero, and contracts the suspension devices D1, D2, D3, and D4, so that the ECU 30 side Is recognized from the signal from the current sensor, and the rotational position of the shaft 1a of the motor 1 when the current i1 is zero from the rotational position of the shaft 1a detected by each Hall element H is used as a reference. The rotation angle θ1 up to the current rotation position of the shaft 1a is calculated, the relationship between the current i1 and the rotation angle θ1 is graphed, and this is stored in the ECU 30 as a normal value. That is, in the above operation, as shown in FIG. 4, the relationship between the current i1 and the rotation angle θ1 is made into a graph indicated by a line A. This graphing operation is performed, for example, in a state in which no passenger or luggage is loaded on the vehicle when the vehicle is shipped.

  In the above description, the relationship between the current i1 and the rotation angle θ1 of the shaft 1a is graphed, but the voltage i may be used instead of the current i1. In this case, a known voltage sensor is connected to the ECU 30 so that the voltage v can be grasped from a signal detected by the voltage sensor. Furthermore, the relative displacement x between the vehicle body side members B1, B2, B3, B4 and the axle side members S1, S2, S3, S4 calculated from the rotation angle θ1 and the lead of the screw shaft 3 instead of the rotation angle θ1 may be used. .

  Further, since the actual vehicle suspension includes a spring element such as a bump stopper (not shown), the line A becomes nonlinear with respect to the current i1, and the portion of the line A1 on the line A is the suspension devices D1, D2, D3. , D4 indicate a so-called fully extended state, A2 indicates a section where the spring force of the suspension springs K1, K2, K3, K4 is dominant, and A3 indicates a bump (not shown). The section where the influence of the spring force of the rubber of the stopper is shown.

  Further, in the above description, the relationship between the current i1 and the rotation angle θ1 is graphed, but instead, for example, the current i1 is changed by every 0.1 amperes and the corresponding rotation angle θ1 is detected. In particular, the relationship between the current i1 and the rotation angle θ1 at that time is stored in the ECU 30 as the values of the normal current i1 and the rotation angle θ1, that is, the relationship between the current i1 and the rotation angle θ1 is not a continuous line. The ECU 30 may be recognized as follows.

  Further, the rotational position of the shaft 1a of the motor 1 when only the vehicle body is suspended and balanced by the suspension springs K1, K2, K3, and K4 is separately stored in the ECU 30 as a reference shaft rotational position.

  Here, if the Hall element H and the ECU 30 are energized even when the vehicle is stopped, the rotation angle from the reference shaft rotation position is changed even if the boarding vehicle gets on the vehicle and the vehicle body weight changes. However, when the hall element H and the ECU 30 are not energized when the engine is stopped, the hall element H can only detect the rotational position of the shaft 1a. If the shaft 1a rotates 360 degrees or more from the reference shaft rotation position due to the above, for example, when the shaft 1a rotates 500 degrees from the reference shaft rotation position, the ECU 30 rotates 140 degrees from the reference shaft rotation position. It will be in a state where it can not be judged whether it was done. Therefore, when the hall element H and the ECU 30 are not always energized, a stroke sensor capable of detecting the relative movement of each suspension device D1, D2, D3, D4 is separately provided, for example, as shown in FIG. What is necessary is just to provide a position detection means. The stroke position detection means shown in FIG. 6 includes a plurality of pairs of electrodes 50 provided on the inner periphery of the outer cylinder 2 and an annular conductive member 60 fitted on the outer periphery side of the inner cylinder 5. One of the electrodes 50 is connected to a power source of the ECU 30 and the other is connected to an input port 100 of a PIO (Parallel Input Output). When this electrode 50 comes into contact with the conductive member 60, one of the electrodes 50 is connected. Are electrically connected to each other via the conductive member 60, and the input port 100 of the PIO is set to a high level. Further, the axial length of the conductive member 60 is exactly two electrodes. The electrode 50 is set to such a length that can be energized, and the electrode 50 is electrically connected when the shaft 1a rotates 180 degrees in relation to the axial length of the conductive member 60. With intervals such as next to the electrode 50 is energized, it is provided along the axial direction of the outer cylinder 2. That is, according to this stroke position detecting means, the ECU 30 can determine the position of the shaft 1a of the motor 1 within an error of 180 degrees depending on which electrode 50 is energized, and further, the Hall element H Since the position of the shaft 1a can be recognized within a range of 360 degrees, the position of the shaft 1a of the motor 1 can be accurately recognized by the stroke position detecting means and the Hall element H.

  Next, the self-diagnosis process of the above embodiment will be described with reference to FIG. That is, the process of FIG. 3 confirms whether or not the vehicle occupant intends to perform a self-diagnosis process in Step P1. This process is confirmed by the operation of the vehicle occupant's select switch. Specifically, it is determined by whether or not the select switch is in the self-diagnosis processing position. When the select switch takes the self-diagnosis processing position, a signal is sent to the ECU 30 side, the self-diagnosis process is executed as an interrupt process, and the process proceeds to Step P2.

  In step P2, for example, it is determined whether the vehicle speed detected by the vehicle speed sensor is zero or the side brake is on, that is, whether the vehicle is stopped. If determined, the process proceeds to step P3, and the interrupt process is terminated without performing the self-diagnosis process.

  On the other hand, if it is determined that the vehicle is stopped, the process proceeds to step P4. First, from the rotational position of the shaft 1a of the motor 1 detected by the Hall element H, how much the shaft 1a from the reference shaft rotational position is detected. Is detected, that is, the rotation angle w of the shaft 1a caused by the weight change of the vehicle body is detected, and the ECU 30 temporarily stores the rotation angle w in the storage device of the ECU 30.

  And it transfers to step P5, ECU30 supplies the electric current i1 to the motor 1 gradually increasing from zero, receives the signal from a current sensor, grasps | ascertains the magnitude | size of the electric current i1, and with respect to the electric current i1 The changing rotation angle θ1 is grasped from the signal from the Hall element H, and the relationship between the current i1 and the rotation angle θ1 at this time is graphed and stored in the storage device.

  Subsequently, the process proceeds to Step P6, and this time, the ECU 30 supplies the current i1 to the motor 1 while gradually decreasing from zero, receives a signal from the current sensor, grasps the magnitude of the current i1, The rotation angle θ1 changing with respect to i1 is grasped from the signal from the Hall element H, and the relationship between the current i1 and the rotation angle θ1 at this time is graphed and stored in the storage device.

  Then, the process proceeds to step P7, with the rotation angle w obtained in step 4 as a reference, as shown in FIG. 5, the graph indicating the normal state is offset, and the line A is rotated along the rotation angle θ1. The line Aoff is shifted by W and the current iw necessary to cancel the rotation angle w along the current i1 axis. That is, the influence of the vehicle body weight change is excluded here.

  Further, the process proceeds to step P8, where the ECU 30 compares the graph showing the normal state offset in step P7 with the graphs obtained in step P5 and step P6, and the active suspension is in a normal state. Determine whether or not. Here, as a determination method, as shown in FIG. 5, a threshold is provided with reference to a graph (line Aoff) indicating a normal state that is offset. For example, the current i1 and the rotation angle θ1 during self-diagnosis If the graph showing the relationship is within ± 10% of the deviation from the normal graph, it is determined to be normal, and if it exceeds the threshold, it is determined to be abnormal. Therefore, in this case, whether or not it is within the set threshold is a predetermined reference.

  Then, the process proceeds to step P9. When the self-diagnosis result is determined to be normal, the interrupt process is terminated, and when it is determined to be abnormal, the process proceeds to step 10.

  In step P10, the ECU 30 outputs a control signal to the alarm device in order to notify the vehicle occupant that the active suspension is abnormal, and proceeds to step P11.

  Finally, in step P11, since the actuator functions of the suspension devices D1, D2, D3, and D4 are abnormal, if active control is performed in this state, the vibration characteristics of the vehicle body will change. Do not perform active control.

  In the self-diagnosis process, it may be determined whether the voltage is normal by using the voltage v instead of the current i1, and is calculated from the rotation angle θ1 and the lead of the screw shaft 3 instead of the rotation angle θ1. The relative displacement x between the vehicle body side members B1, B2, B3, and B4 and the axle side members S1, S2, S3, and S4 may be used for determination.

In the case of the present embodiment, it is determined that there is an abnormality in the active suspension by not following the line A in which the rotation angle θ1 is in a normal state with respect to the current i1. Examples include failure of wiring, failure of drive circuit in ECU 30, failure of motor 1, deterioration damage of suspension springs K1, K2, K3, K4, etc. If a failure detection means for detecting disconnection or the like is provided, it is possible to determine which member or wiring of the active suspension has a failure. If it is possible to detect a failure of each part other than the suspension springs K1, K2, K3, K4, if it is determined that each part other than the suspension springs K1, K2, K3, K4 is normal, the suspension spring K1, Since the deterioration damage of K2, K3, and K4 can be determined, in this case, the means for detecting the deterioration damage of the suspension springs K1, K2, K3, and K4 may be omitted. When the failure detection means for each part is provided, especially in the case of an electrical failure, it may be considered that the active control may be disturbed if the active control is continued. Therefore, the suspension spring K1 is assumed to stop the active control. , K2, K3, and K4, it can be determined that only the spring constant is changed, and the active control may be continued in response to the change in the spring constant, and the suspension springs K1, K2, K3, and K4 are air springs. In some cases, if the others are normal, the torque of the motor 1 with respect to the current i1 is not changed, so that the exact spring constant of the air spring can be calculated from the current i1, and a predetermined spring constant is obtained. The ECU 30 may drive an air spring compressor or an exhaust valve so as to ensure the air pressure in the air spring to be realized.

  As described above, this active suspension self-diagnosis device makes a determination based on the current value or voltage value supplied to the motor and the rotation angle of the shaft of the motor or the relative displacement between the vehicle body side member and the axle side member. Therefore, it is possible to accurately determine whether or not the actuator function of the active suspension functions normally.

  In addition, if a self-diagnosis is performed when the vehicle is stopped, the abnormality of the active suspension can be detected and the passenger can be notified before the vehicle starts, ensuring the safety of the passenger. be able to.

  In addition, when an abnormality is detected in the active suspension, it can function as a normal suspension by stopping the active control, and in this respect as well, it is possible to ensure the safety of the occupant, and there is a risk of hindering vehicle travel. It can be avoided.

  Further, when the abnormality of the active suspension is only a change in the spring constant of the suspension spring that suspends the vehicle body, it is possible to perform active control in accordance with the change in the spring constant.

In addition, a graph showing the normal relationship between the rotation angle of the motor shaft relative to the current value or voltage value supplied to the motor or the relative displacement between the vehicle body side member and the axle side member and the motor created during self-diagnosis By comparing the rotation angle of the motor shaft with respect to the change in the current value or voltage value or the graph showing the change in relative displacement of the vehicle body side member and the axle side member, it is determined whether the vehicle is normal or not. Self-diagnosis corresponding to the above is possible, and an abnormality can be accurately detected.

In addition, by correcting the graph showing the normal relationship between the rotation angle of the motor shaft or the relative displacement of the vehicle body side member and the axle side member with respect to the current value or voltage value supplied to the motor due to the change in the vehicle body weight, Compared to the graph showing the change in the rotation angle of the motor shaft or the relative displacement of the vehicle body side member and the axle side member with respect to the change in the current value or voltage value supplied to the motor to be created, Abnormalities can be detected accurately.

  In the above description, the self-diagnosis processing of the actuator function of the active suspension has been described. However, in this embodiment, it is diagnosed whether the dynamic characteristics of the active suspension, that is, the vibration suppression characteristics are normal. You can also.

  Hereinafter, the vibration suppression characteristic self-diagnosis process will be described in detail. First, the normal vibration suppression characteristic of the active suspension is measured by the ECU 30. This measurement is performed, for example, in a state where no passenger or luggage is loaded on the vehicle when the vehicle is shipped.

And this vibration suppression characteristic is represented as a vibration suppression characteristic graph which shows the relationship between rotation angle (theta) 2 of the shaft 1a of the motor 1, and time, and is previously stored in the memory | storage device of ECU30. And the said vibration suppression characteristic graph is produced in the procedure shown, for example in FIG. Here, when the current i2 is supplied to each motor 1, when the current i2 takes a positive value, the force F is applied in the direction in which each motor 1 is rotated forward to extend the suspension devices D1, D2, D3, D4. On the other hand, when the current i2 takes a negative value, it is assumed that a force F is generated in a direction in which each motor 1 is reversed and the suspension devices D1, D2, D3, D4 are contracted.

First, as shown in FIG. 7, in step Q1, the spring constants k of the suspension springs K1, K2, K3, and K4 of the normal suspension devices D1, D2, D3, and D4 are measured. Specifically, currents are respectively supplied to the motors 1 of the suspension devices D1, D2, D3, and D4, the suspension devices D1, D2, D3, and D4 are expanded and contracted, and each motor 1 is generated from the current i2 output on the ECU 30 side. The torque F of the suspension devices D1, D2, D3, and D4 is calculated from the torque, and how much the suspension springs K1, K2, K3, and K4 with respect to the force F are calculated. rotational position of whether it has telescopic shaft 1a detected by the Hall elements H, i.e., the rotational position of the shaft 1a of the motor 1 when the current i2 is zero from the rotational position of the shaft 1a to be detected by the Hall elements H A rotation angle θ2 up to the current rotational position of the shaft 1a is calculated as a reference, and the vehicle body side members B1, B2, B3, B4 are suspended from the suspension spring K based on the rotation angle θ2. The amount of relative displacement between the vehicle body side members B1, B2, B3, and B4 and the axle side members S1, S2, S3, and S4 is calculated based on the state of being suspended by 1, K2, K3, and K4. Then, an accurate spring constant k of each suspension spring K1, K2, K3, K4 is calculated from each relative displacement x and the force F, and is stored in a storage device in the ECU 30. Since the actual vehicle suspension includes spring elements such as bump stoppers, the accurate and total vehicle body side member B1 includes not only the suspension springs K1, K2, K3 and K4 but also spring elements such as bump stoppers. , B2, B3, B4 and the relative displacement x of the axle side members S1, S2, S3, S4, it is possible to obtain a non-linear spring constant k.

Subsequently, the process proceeds to step Q2, and in step Q2, after obtaining an accurate spring constant k for each vehicle wheel, the ECU 30 performs the vehicle body side members B1, B2, B3, B4 and the axle side members S1, S2, and so on. The sprung mass m of each vehicle wheel is calculated from the relative displacement x of S3 and S4 and the obtained spring constant k, and this sprung mass m is stored as a reference sprung mass in the storage device. Then, from this spring constant k and the obtained sprung mass m, a reference vibration frequency fg is calculated from the formula fg = (1 / 2π) (k / m) ^1/2 , and this reference vibration frequency is obtained. fg is stored in the storage device, and the process proceeds to step Q3. When calculating the sprung mass m of each vehicle wheel, the sprung mass of each vehicle wheel at the time of shipment of the vehicle is measured and stored in the ECU 30, and the spring constant k is calculated as the value. And the amount of sprung mass change calculated from the relative displacement x. In calculating the sprung mass m, in step Q2, a current is supplied to each motor 1 to vibrate the vehicle to freely vibrate the vehicle body side members B1, B2, B3, B4. The sprung mass m may be calculated from the vibration frequency and the spring constant k.

Further, in step Q3, the ECU 30 applies a current i2 to each of the motors 1 of the suspension devices D1, D2, D3, and D4 until a predetermined rotation angle φ is obtained, and each of the suspension devices D1, D2, D3, and D4 is applied. Stretch or shrink . Then, the supply of the current i2 is stopped from that state, and the vehicle body is vibrated. That is, the vehicle body is vibrated. Stopping the current supply may be made to gradually reduce the current to zero or instantaneously to zero. Further, in the above description, when the vehicle body is vibrated, the current i2 is stopped by supplying the current i2 that realizes the predetermined rotation angle φ to each motor 1, but instead of this, the vehicle May be gradually vibrated in accordance with the natural frequency of the sprung member, that is, the vehicle body side members B1, B2, B3, and B4. In this case, the suspension devices D1, D2, D3, and D4 are continuously expanded and contracted. Therefore, it is only necessary to supply current to each motor 1 and finally stop the current supply when a predetermined rotation angle φ is realized. By doing this, the unsprung vibration of the vehicle and the high-frequency vibration mode of each part of the vehicle can be set. Since excitation can be prevented and only the natural vibrations of the vehicle body side members B1, B2, B3, and B4 can be excited, evaluation errors can be reduced and accurate self-diagnosis can be performed.

  Then, the process proceeds to step Q4. In step Q4, after the current supply is stopped, the relationship between the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, and D4 and the time t is graphed after a lapse of a certain time. This is stored in the ECU 30 as a normal value. That is, in the above operation, as shown in FIG. 8, the relationship between the rotation angle θ2 and time t is made into a graph indicated by line E of the vibration suppression characteristic graph. This graphing operation is performed in a state where no passenger or luggage is loaded on the vehicle as described above. Here, when the vibration suppression characteristic graph is obtained, the current i2 is not supplied from the ECU 30, and the coil 6 of each motor 1 is induced by the shaft 1a of each motor 1 being forcibly driven. The rotation angle θ2 is measured so that only the current caused by the electromotive force flows. The obtained vibration suppression characteristic graph shows the vibration suppression characteristic when each suspension device D1, D2, D3, D4 functions as a shock absorber. The vibration suppression characteristic graph obtained here is referred to as a damping characteristic graph for convenience.

Further, the process proceeds to step Q5. In step Q5, the ECU 30 applies a current i2 that realizes a predetermined rotation angle φ to each of the motors 1 of the suspension devices D1, D2, D3, and D4. D2, D3, and D4 are expanded or contracted , respectively. Also in this case, the supply of the current i2 is stopped from that state, and the vehicle body is vibrated. For stopping the current supply, the current i2 may be gradually reduced to zero or may be instantaneously zero.

  Then, the process proceeds to step Q6. After the current supply is stopped in step Q6, the current supply is performed in accordance with the active control processing procedure stored in the ECU 30 from the current supply stop state. Then, the current i2 is gradually supplied so that the current value necessary for vibration suppression calculated by the ECU 30 is obtained after a certain period. Further, the relationship between the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, and D4 and the time t is graphed after the lapse of the predetermined time, and this is stored in the ECU 30 as a normal value at the time of active control. . That is, in the above operation, similar to the above-described attenuation characteristic graph, although not shown, the relationship between the rotation angle θ2 and time t is made into a graph shown by the vibration suppression characteristic graph. This graphing operation is performed in a state where no passenger or luggage is loaded on the vehicle as described above. The vibration suppression characteristic graph obtained here is referred to as a control damping characteristic graph for convenience. Further, the vibration frequency fa is calculated from the interval between the zero cross points where the measured rotation angle θ2 intersects the time t-axis, and the vibration frequencies fa of the vehicle body side members B1, B2, B3, B4 during the self-diagnosis process. Is stored in the storage device.

Further, the process proceeds to step Q7. In step Q7, the ECU 30 applies a current i2 that realizes a predetermined rotation angle φ to each of the motors 1 of the suspension devices D1, D2, D3, and D4. D2, D3, and D4 are expanded or contracted , respectively. Also in this case, the supply of the current i2 is stopped from that state, and the vehicle body is vibrated. For stopping the current supply, the current i2 may be gradually reduced to zero or may be instantaneously zero.

  Then, the process proceeds to step Q8. In step Q8, after the current supply is stopped, this time, from the state where the coils 6 of the motors 1 are closed via the ECU 30, for example, relay switches (not shown). The coil 6 is disconnected, no current flows through the coil 6, and the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, D4 and the time t The relationship is graphed, and this is stored in the ECU 30 as a normal value indicating the vibration suppression characteristic of only the friction of the suspension devices D1, D2, D3, and D4. That is, in the above operation, similar to the above-described attenuation characteristic graph, although not shown, the relationship between the rotation angle θ2 and time t is made into a graph shown by the vibration suppression characteristic graph. The vibration suppression characteristic graph obtained here is referred to as a friction damping characteristic graph for convenience.

  Through the above operations, all three types of graphs are obtained, and these graphs are stored in the storage device of the EUC 30.

  Further, it is not necessary to create each attenuation characteristic graph stored in the storage device of the ECU 30 by using the ECU 30, and it is created by using the computer system for graph creation for the suspension devices D1, D2, D3, and D4. Of course it is good.

  In the suspension devices D1, D2, D3, and D4 in the present embodiment, the spring constant k of the suspension spring elements such as the suspension springs K1, K2, K3, and K4 can be accurately grasped. The ECU 30 stores a vibration analysis program and a program for calculating an optimum control force from the result of the vibration analysis, and executes these programs, or a plurality of spring constants k in advance in view of changes in the spring constant k due to aging degradation or the like. By preparing a control gain map corresponding to the above, and making this map refer to the ECU 30 for active control, it is possible to take into account changes in the spring constant due to aging of the suspension springs K1, K2, K3, K4, etc. Vibration suppression is possible.

  In the above description, the relationship between the rotation angle θ2 of the shaft 1a with respect to the time t is graphed, but the vehicle body side member calculated from the rotation angle θ2 and the lead of the screw shaft 3 instead of the rotation angle θ2. The relative displacement x between B1, B2, B3, B4 and the axle side members S1, S2, S3, S4 may be used.

  Next, the vibration suppression characteristic self-diagnosis process will be described with reference to FIG. That is, the process of FIG. 9 confirms whether or not the vehicle occupant intends to perform the self-diagnosis process in step R1. This process is confirmed by the operation of the vehicle occupant's select switch. Specifically, it is determined by whether or not the select switch is in the self-diagnosis processing position. When the select switch takes the self-diagnosis processing position, a signal is sent to the ECU 30 side, the self-diagnosis process is executed as an interrupt process, and the process proceeds to step R2.

  In step R2, for example, it is determined whether the vehicle speed detected by the vehicle speed sensor is zero or the side brake is on, that is, whether the vehicle is stopped. If it is determined, the process proceeds to step R3, and the interrupt process is terminated without performing the self-diagnosis process.

  On the other hand, if it is determined that the vehicle is stopped, the process proceeds to step R4. First, from the rotational position of the shaft 1a of the motor 1 detected by the hall element H, how much the shaft 1a from the reference shaft rotational position is detected. Is detected, that is, the rotation angle w of the shaft 1a caused by the weight change of the vehicle body is detected, and the ECU 30 stores the rotation angle w and determines the vehicle body side member from the rotation angle w and the lead of the screw shaft 3. The relative displacement x of B1, B2, B3, B4 and the axle side members S1, S2, S3, S4 is calculated. The calculated relative displacement x and the spring constants k of the suspension springs K1, K2, K3, K4. From this, the sprung mass m1 is calculated, each sprung mass m1 is temporarily stored in the storage device of the ECU 30, and the process proceeds to Step R5.

  Further, in step R5, the ECU 30 applies an electric current to each motor 1 so as to cancel the rotation angle w, that is, so that the shaft 1a of each motor 1 becomes a reference rotational position. Further, a current i2 that realizes the rotation angle φ is applied from the state.

  Then, the ECU 30 stops supplying only the current i2, and then supplies current to each motor 1 so as to generate the control force Fs1 in the suspension devices D1, D2, D3, and D4. Specifically, the control force Fs1 is set so as to be derived by the following formula: Fs1 = a · C1 · v + a · k · x. Here, a is a mass change correction coefficient calculated by a = m1 / m, C1 is a damping coefficient of each suspension device D1, D2, D3, D4, and v is a vehicle body side obtained by differentiating relative displacement x. This is the relative speed v between the members B1, B2, B3, B4 and the axle side members S1, S2, S3, S4. Here, the damping coefficient C1 is an electromagnetic force generated when the shaft 1a of each motor 1 of the suspension devices D1, D2, D3, D4 is forcibly driven by the expansion and contraction of the suspension devices D1, D2, D3, D4. It is determined based on the torque resulting from.

  The control force Fs1 is calculated for each suspension device D1, D2, D3, D4, and the ECU 30 applies the suspension devices D1, D2, D3, D4 to the motors 1 of the suspension devices D1, D2, D3, D4, respectively. A current is supplied to generate the control force Fs1 calculated every time. At this time, in practice, the magnitude of the current supplied to each motor 1 needs to maintain the current value supplied to cancel the sprung mass change, and therefore corresponds to the control force Fs1. This is a value obtained by adding a current value that cancels the sprung mass change to the current value. In this way, since the control force Fs1 is generated in the suspension devices D1, D2, D3, and D4, the vibration transfer function is the vibration transfer function and the sprung mass when the sprung mass is the reference sprung mass m. Since the transfer function of vibration when the mass is m1 is exactly the same, the sprung resonance frequency and the damping rate do not change and the vibration does not change, that is, even if the sprung mass changes. Since the vibration is always the same as that of the reference sprung mass m, that is, the influence of the sprung mass change and the damping rate change can be eliminated. Further, since the rotation angle w is once canceled, even if the spring constant k of the suspension springs K1, K2, K3, K4 is non-linear with respect to the relative displacement x, it can be vibrated under the same conditions.

  Then, the relationship between the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, and D4 and the time t on the basis of the elapse of a certain period after the supply of only the current i2 is stopped, as shown in FIG. A graph is formed as indicated by Er, and this is stored in the ECU 30 as an attenuation characteristic graph during the self-diagnosis process. At this time, no current is supplied from the ECU 30 to the coil 6 of each motor 1 except for the current for canceling the control force Fs1 and the rotation angle w, and other than the current for canceling the control force Fs and the rotation angle w. The rotation angle θ2 is measured so that only the current caused by the induced electromotive force generated by forcibly driving the shaft 1a of each motor 1 flows.

  Further, the vibration frequency f1 during the self-diagnosis process is calculated from the interval between the zero cross points where the measured rotation angle θ2 intersects the time t-axis, and the vehicle body side members B1, B2, B3 during the self-diagnosis process are calculated. The vibration frequency f1 of B4 is stored in the storage device, and the process proceeds to step R6.

  In step R6, the ECU 30 applies an electric current to each motor 1 so as to cancel the rotation angle w, that is, so that the shaft 1a of each motor 1 becomes a reference rotational position. Further, a current i2 that realizes the rotation angle φ is applied from the state.

  Then, the ECU 30 stops supplying only the current i2, and then supplies current to each motor 1 in order to generate the control force Fs2 in the suspension devices D1, D2, D3, and D4. Specifically, the control force Fs2 is set so as to be derived by the following formula: Fs2 = a · C2 · v + a · k · x. Here, a is a mass change correction coefficient calculated by a = m1 / m, C2 is a damping coefficient of each suspension device D1, D2, D3, D4, and v is a vehicle body side obtained by differentiating relative displacement x. This is the relative speed v between the members B1, B2, B3, B4 and the axle side members S1, S2, S3, S4. Here, the damping coefficient C2 is a damping coefficient when the suspension devices D1, D2, D3, and D4 function as a shock absorber when the suspension devices D1, D2, D3, and D4 are actively controlled. It is determined by an active control program stored in the apparatus, and changes depending on, for example, the vibration frequency and vibration speed of the suspension apparatuses D1, D2, D3, and D4.

  The control force Fs2 is calculated for each of the suspension devices D1, D2, D3, D4, and the ECU 30 applies the suspension devices D1, D2, D3, D4 to the motors 1 of the suspension devices D1, D2, D3, D4, respectively. A current is supplied to generate the control force Fs2 calculated every time. At this time, in reality, the magnitude of the current supplied to each motor 1 needs to maintain the current value supplied to cancel the sprung mass change, and therefore corresponds to the control force Fs2. This is a value obtained by adding a current value that cancels the sprung mass change to the current value. Thus, since the control force Fs2 is generated in the suspension devices D1, D2, D3, and D4, the vibration transfer function is the same as the vibration transfer function and the sprung mass when the sprung mass is the reference sprung mass m. Since the transfer function of vibration when the mass is m1 is exactly the same, the sprung resonance frequency and the damping rate do not change and the vibration does not change, that is, even if the sprung mass changes. Since the vibration is always the same as that of the reference sprung mass m, that is, the influence of the sprung mass change and the damping rate change can be eliminated. Further, since the rotation angle w is once canceled, even if the spring constant k of the suspension springs K1, K2, K3, K4 is non-linear with respect to the relative displacement x, it can be vibrated under the same conditions.

  Then, the relationship between the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, and D4 and the time t is graphed on the basis of a certain period after the supply of only the current i2 is stopped. This is stored in the ECU 30 as a control attenuation characteristic graph during the self-diagnosis process. The ECU 30 supplies current in accordance with the active control processing procedure stored in the ECU 30 from the current i2 supply stop state. At this time, in addition to the amount of current associated with the active control, the current that cancels the rotation angle w. Therefore, the ECU 30 provides each motor 1 with a current amount of the sum of the current amount for active control, the current amount for canceling the rotation angle w, and the current amount associated with the control force Fs2. Supply each.

  Further, the vibration frequency f2 during the self-diagnosis process is calculated from the interval between the zero cross points where the measured rotation angle θ2 intersects the time t-axis, and the vehicle body side members B1, B2, B3 during the self-diagnosis process are calculated. The vibration frequency f2 of B4 is memorize | stored in a memory | storage device, and it transfers to step R7.

  Subsequently, the process proceeds to step R7, and the ECU 30 applies an electric current to each motor 1 so as to cancel the rotation angle w, that is, so that the shaft 1a of each motor 1 becomes a reference rotational position. Further, a current i2 that realizes the rotation angle φ is applied from the state.

Then, the ECU 30 stops supplying only the current i2, and then supplies current to each motor 1 so that the suspension devices D1, D2, D3, and D4 generate the control force Fs3. Specifically, the control force Fs3 is set so as to be derived by the formula of Fs3 = a · k · x. Here, a is a mass change correction coefficient calculated by a = m1 / m .

  The control force Fs3 is calculated for each of the suspension devices D1, D2, D3, D4, and the ECU 30 applies the suspension devices D1, D2, D3, D4 to the motors 1 of the suspension devices D1, D2, D3, D4, respectively. A current is supplied to generate the control force Fs3 calculated every time. At this time, in reality, the magnitude of the current supplied to each motor 1 needs to maintain the current value supplied to cancel the sprung mass change, and therefore corresponds to the control force Fs3. This is a value obtained by adding a current value that cancels the sprung mass change to the current value. Thus, since the control force Fs3 is generated in the suspension devices D1, D2, D3, and D4, the vibration transfer function is the vibration transfer function and the sprung mass when the sprung mass is the reference sprung mass m. Since the transfer function of vibration when the mass is m1 is exactly the same, the sprung resonance frequency and the damping rate do not change and the vibration does not change, that is, even if the sprung mass changes. Since the vibration is always the same as that of the reference sprung mass m, that is, the influence of the sprung mass change and the damping rate change can be eliminated. Further, since the rotation angle w is once canceled, even if the spring constant k of the suspension springs K1, K2, K3, K4 is non-linear with respect to the relative displacement x, it can be vibrated under the same conditions.

  Then, the relationship between the rotation angle θ2 of the motor 1 of the suspension devices D1, D2, D3, and D4 and the time t is graphed on the basis of a certain period after the supply of only the current i2 is stopped. This is stored in the ECU 30 as a friction damping characteristic graph during the self-diagnosis process. At this time, in addition to the current for canceling the control force Fs3 and the rotation angle w from the ECU 30, a current for canceling the current caused by the induced electromotive force generated when the shaft 1a of each motor 1 is forcibly driven. In other words, the rotation angle θ2 is measured so as to create a state similar to the state in which the coil 6 of each motor 1 is disconnected.

  Further, the vibration frequency f3 during the self-diagnosis process is calculated from the interval between the zero cross points where the measured rotation angle θ2 intersects the time t-axis, and the vehicle body side members B1, B2, B3 during the self-diagnosis process are calculated. The vibration frequency f3 of B4 is memorize | stored in a memory | storage device, and it transfers to step R8.

  Subsequently, the process proceeds to step R8, and the ECU 30 compares each graph indicating the normal state with each graph obtained during the self-diagnosis diagnosis process obtained in steps R5, R6, and R7. That is, the attenuation characteristic graph indicating the normal state, the attenuation characteristic graph during the self-diagnosis process, the control attenuation characteristic graph indicating the normal state, the control attenuation characteristic graph during the self-diagnosis process, and the friction indicating the normal state The damping characteristic graph and the friction damping characteristic graph during the self-diagnosis process are respectively compared to determine whether or not the active suspension is in a normal state.

  Here, as a determination method, for example, as shown in FIG. 8, a threshold value is provided with reference to the Nth peak value Yn of the rotation angle θ2 in the graph indicating the normal state, and the corresponding self If the N-th peak value Yrn of the rotation angle θ2 in the graph at the time of diagnosis processing is within ± 10% of the deviation from the peak value Yn, it is determined to be normal, and the case where it exceeds this threshold is determined to be above. . In addition, a plurality of peak values may be extracted, a threshold value may be provided for each peak value indicating a normal state, and compared with each corresponding peak value of the graph during the self-diagnosis process, particularly during active control In some cases, it may not be possible to extract a plurality of peak values due to vibration suppression. In such a case, the determination may be made based only on the first peak value. The peak value may be extracted by comparing the minus peak value when the suspension devices D1, D2, D3, and D4 contract. In addition to the peak value comparison, a comparison may be made by providing a threshold over the entire graph showing the relationship between the time t and the rotation angle θ2.

In addition to determining from the peak value itself as described above, for example, the first peak value Y1 and the Nth peak value Yn of normal values are extracted to calculate Y1 / Yn, , It may be determined whether or not it is normal by comparing with the value of Y1 / Yn at the time of the self-diagnosis processing, and further, from the value of Y1 / Yn,
Attenuation rate ζ = (1 / 2π) · {1 / (n−1)} log _e (Y1 / Yn) is calculated, and the normal value attenuation rate is compared with the attenuation rate during the self-diagnosis process. You may do that.

  Furthermore, in the present embodiment, a comparison is made between the vibration frequency fg indicating the normal value and the vibration frequency f1 during the self-diagnosis process, and a comparison between the vibration frequency fa indicating the normal value and the vibration frequency f2 during the self-diagnosis process. Further, the vibration frequency fg indicating the normal value is compared with the vibration frequency f3 at the time of the self-diagnosis process, and a threshold value is provided with reference to the vibration frequency indicating the normal value, and the vibration frequency at the time of the self-diagnosis process falls within this threshold value. It may be determined that there is an abnormality when there is not.

  In any of the cases described above, a threshold value is provided based on the normal value, and whether each value during the self-diagnosis process is within the threshold value is a predetermined criterion.

  In the above description, the rotation angle θ2 is used. Instead of the rotation angle θ2, the relative displacement x of the vehicle body side members B1, B2, B3, B4 and the axle side members S1, S2, S3, S4 It is also possible to make a self-diagnosis using the relative speed v, the relative acceleration, the absolute displacement, the absolute speed, and the absolute acceleration of the vehicle body side members B1, B2, B3, and B4.

  Further, in the present embodiment, when performing self-diagnosis of the vibration suppression characteristics of the suspension devices D1, D2, D3, and D4, the vehicle body is first vibrated in a normal state to obtain respective graphs indicating normal values. However, assuming that the ECU 30 stores a program that can perform vibration analysis, the sprung mass, the spring constants of the suspension springs K1, K2, K3, and K4 in each wheel and the damping of the suspension devices D1, D2, D3, and D4 Each graph as a theoretical value may be calculated from the coefficient C1, and each graph as the theoretical value may be compared with each graph at the time of self-diagnosis processing to determine whether there is an abnormality.

Further, in the present embodiment, three graphs of a damping characteristic graph, a control damping characteristic graph and a friction damping characteristic graph are obtained. If an abnormality occurs in the damping characteristic graph, the suspension devices D1, D2, D3, If it is detected that there is an abnormality in the function of D4 as a shock absorber or that the spring constant k is changed, and an abnormality has occurred in the damping characteristic graph during control, the actuators of the suspension devices D1, D2, D3, D4 and If it is detected that there is an abnormality in the function as a shock absorber or the spring constant k is changed and an abnormality occurs in the friction damping characteristic graph, the hardware of the suspension devices D1, D2, D3, D4, that is, the screw axis 3, is strange or spring constant k abnormality in any one or more positions of the ball screw nut 4 and the motor 1 occurs That it can detect. Therefore, as long as the purpose is simply to detect an abnormality, it may be determined from any one of the graphs whether or not it is normal. However, since an abnormal part can be specified by comparing three graphs, there is an advantage of using three graphs at that point. Further, it may be determined whether or not it is normal only by either the vibration frequency comparison or the peak value comparison.

  In addition, a plurality of graphs indicating normal values are prepared by changing the rotation angle φ, and the vehicle body is vibrated at each corresponding rotation φ to obtain three graphs for each rotation angle φ. For each φ, it may be determined whether the active suspension is normal or abnormal. In this case, the processing from Step Q3 to Step Q8 for obtaining a graph showing normal values is repeated for each rotation angle φ, and the above Step R5 is performed. To R8 may be repeated for each rotation angle φ. This is particularly effective when the spring constant k is nonlinear with respect to the rotation angle θ2 of the shaft 1a or when the damping coefficient is nonlinear with respect to the relative speed v. There is an advantage that it becomes easy to identify.

  In the above description, the case where the suspension devices D1, D2, D3, and D4 are simultaneously excited when the vehicle body is vibrated has been described. However, the processing from Step R5 to Step R8 is performed for each suspension device D1, D2, and D4. It may be performed in order for each of D3 and D4, or may be vibrated in order in two places on the vehicle front wheel side and two places on the rear wheel side. However, in this case, it is necessary to make the vibration state of the vehicle body at the time of self-diagnosis processing the same as the vibration state of the vehicle body when obtaining a normal value.

  As described above, the ECU 30 determines whether or not the active suspension is normal, finishes the process of step R8, and proceeds to step R9.

  In step R9, if the self-diagnosis result is determined to be normal, the interrupt process is terminated, and if it is determined to be abnormal, the process proceeds to step R10.

  In step R10, the ECU 30 outputs a control signal to the alarm device to notify the vehicle occupant that the active suspension is abnormal, and proceeds to step P11.

  Finally, in step R11, since the actuator functions of the suspension devices D1, D2, D3, and D4 are abnormal, if active control is performed in this state, the vibration characteristics of the vehicle body will change. Do not perform active control.

If it is determined that there is an abnormality in the active suspension, as in the self-diagnosis of the actuator function of each of the suspension devices D1, D2, D3, D4, current sensor failure, wiring breakage, drive circuit in the ECU 30 Failure, motor 1 failure, deterioration damage of suspension springs K1, K2, K3, K4, etc., and when it is judged as abnormal, failure detection means for detecting failure of each part, disconnection of wiring, etc. If provided, it can be determined which member or wiring of the active suspension has a failure. If it is possible to detect a failure of each part other than the suspension springs K1, K2, K3, K4, if it is determined that each part other than the suspension springs K1, K2, K3, K4 is normal, the suspension spring K1, Since the deterioration damage of K2, K3, and K4 can be determined, in this case, the means for detecting the deterioration damage of the suspension springs K1, K2, K3, and K4 may be omitted. When the failure detection means for each part is provided, especially in the case of an electrical failure, it may be considered that the active control may be disturbed if the active control is continued. Therefore, the suspension spring K1 is assumed to stop the active control. , K2, K3, K4, it can be determined that only the spring constant changes, and the active control may be continued in response to the spring constant change, and the suspension springs K1, K2, K3, K4 are air springs. If the other is normal, the torque of the motor 1 with respect to the current i2 is not changed, so that the exact spring constant of the air spring can be calculated from the current i2, and a predetermined spring constant is realized. The ECU 30 may drive a compressor or an exhaust valve for the air spring so as to secure the air pressure in the air spring.

  As described above, it is possible to accurately determine whether or not the active suspension functions normally by determining whether the vibration suppression characteristics of the active suspension are normal or abnormal.

  Furthermore, if the self-diagnosis of the vibration suppression characteristic is performed when the vehicle is stopped, the abnormality of the active suspension can be detected and the passenger can be notified before the vehicle starts. Can be secured.

Furthermore, when detecting the active suspension abnormality in the self diagnosis of the vibration suppression characteristic, to function as a normal suspension by stopping the active control, it is possible to ensure the safety of the passenger in this point, It is possible to avoid the fear of hindering vehicle travel.

  Also, if the active suspension abnormality is only a change in the spring constants of the suspension springs K1, K2, K3, K4 that suspends the vehicle body in the self-diagnosis of vibration suppression characteristics, active control is performed in accordance with the change in the spring constant. It is also possible to do this.

  Furthermore, if the self-diagnosis of the actuator function of each suspension device D1, D2, D3, D4 and the self-diagnosis of the vibration suppression characteristics of the active suspension are performed, so to speak, whether or not the active suspension is normal is confirmed by double check. This makes it possible to accurately determine the safety of the occupant and to avoid the risk of hindering vehicle travel.

In addition, a graph showing the change in the rotation angle of the motor shaft over time after body vibration during self-diagnosis is created, and this graph and the normal rotation angle of the motor shaft over time after body vibration Since the suspension device is judged to be normal by comparing with a graph showing a change, a self-diagnosis corresponding to each vehicle can be performed and an abnormality can be accurately detected.

  In addition, during self-diagnosis, current or voltage is supplied to the motor to cancel the rotation angle of the motor shaft that accompanies the change in the vehicle weight, and to the suspension device, the change in the sprung vibration frequency and the change in the damping rate due to the change in the vehicle weight are cancelled. Since the control force is generated, the vehicle vibration status at the time of creating a graph showing the change in the rotation angle of the motor shaft over time after normal vehicle vibration can be made the same as the vehicle vibration status at the time of self-diagnosis. That is, the vehicle body can be vibrated under the same conditions regardless of the vehicle body weight change. The normal graph can be compared with the graph showing the change in the rotation angle of the motor shaft over time obtained after the vehicle body vibration obtained under the same conditions, so that abnormalities can be accurately detected regardless of the vehicle body weight change. can do.

  As described above, by detecting the rotational position of the shaft 1a by the Hall element H, the relative displacement x, the relative speed v, the spring constant k, and the sprung mass m are obtained from the rotational angles θ1 and θ2 and the currents i1 and i2. Although it was possible to calculate, instead of using the Hall element H, a magnetic sensor or an optical sensor may be used, and instead of detecting the rotational position of the shaft 1a of the motor 1, the vehicle body side member B1, A displacement sensor or stroke sensor for detecting the relative displacement x between B2, B3, B4 and the axle side members S1, S2, S3, S4 may be used, and a load is used to detect the sprung mass m of each vehicle wheel. A sensor may be used.

  Next, a modification of the above embodiment will be described. In the above description, the screw shaft 3 is rotationally moved. However, in this modified example, the suspension device is moved linearly in the axial direction of the screw shaft 3 as shown in FIG. The rotational motion of the ball screw nut 4 is transmitted to the shaft 51a of the motor 51. In this case, a driving side gear 62 b is provided on the outer periphery of the ball screw nut 4, a driven side gear 62 a meshing with the driving side gear 62 b is provided, and the driven side gear 62 a is connected to the shaft 51 a of the motor 51. The rotational movement of the ball screw nut 4 can be transmitted to the shaft 51a of the motor 51 through a gear mechanism composed of the drive side gear 62b and the driven side gear 62a, and the linear motion of the screw shaft 3 is transferred to the ball screw. The rotational motion of the nut 4 is converted into the rotational motion of the nut 51 so that the rotational motion can be transmitted to the shaft 51a of the motor 51. The motor 51 generates an electromagnetic force, and the torque generated by the electromagnetic force is generated by the screw shaft 3. The relative movement in the axial direction between the ball screw nut 4 and the screw shaft 3 is suppressed using a damping force that suppresses linear motion. Even in this modification, it can function as an actuator by applying torque to the ball screw nut 4. As in the above embodiment, the motor 51 includes a hall element H (not shown) so that the rotational position of the shaft 51a can be detected. The motor 51 is connected to the ECU 30.

  The suspension device according to this modification will be described in detail. The screw shaft 3 is provided with an eye-shaped bracket 50 at the lower end in FIG. 10 so that it can be attached to a location where the suspension device is applied. The screw shaft 3 is rotatably engaged with the ball screw nut 4 and is inserted into the outer cylinder 55.

  The outer cylinder 55 is a bottomed cylinder, and a bracket (not shown) is provided at the upper end in FIG. 10 so that the outer cylinder 55 can be attached to a place where the suspension device is applied. Therefore, particularly when this suspension device is applied to a vehicle, the suspension device can be interposed between the vehicle body and the axle through the eye bracket 50 and a bracket (not shown). .

  10 is connected to a hollow housing 59. The housing 59 is provided with holes 59a, 59b, 59c and a hole 59d. The outer cylinder 55 is provided with a hole 59a in the housing 59. , 59b and connected to the housing 59 so as to be concentric. Further, ball bearings 40 and 41 are fitted in the inner peripheries of the holes 59a and 59b of the housing 59, and the ball screw nut 4 is fitted in the ball bearings 40 and 41, respectively. Accordingly, the ball screw nut 4 can rotate with respect to the housing 59.

  Ball bearings 42 and 43 are also provided in the hole 59 c and the hole 59 d of the housing 59, and the rotating shaft 60 is fitted in the ball bearings 42 and 43. Further, a cylinder 65 is coupled to the housing 59 so as to be concentric with the hole 59 c, and a motor 51 having the same configuration as the motor 1 is fixed in the cylinder 65.

  As described above, when the screw shaft 3 is rotatably engaged with the ball screw nut 4 along the screw groove 3a, and the screw shaft 3 moves linearly in the vertical direction in FIG. Since the screw nut 4 is restricted from moving in the vertical direction in FIG. 10 by the housing 59 and is only allowed to rotate, the ball screw nut 4 is forcibly driven to rotate. That is, the linear motion of the screw shaft 3 is converted into the rotational motion of the ball screw nut 4 by the above mechanism.

  On the other hand, as shown in FIG. 10, the gear mechanism includes a driven gear 62a formed on the outer periphery of the rotating shaft 60 and a drive gear 62b formed on the outer periphery of the ball screw nut 4, and the teeth of the gears 62a and 62b. Are arranged horizontally so as to mesh with each other and are rotatably inserted into the housing 59, and the rotating shaft 60 is coupled to the shaft 51 a of the motor 51.

  In addition, what is necessary is just to use well-known gears, such as an involute gear, for example, and each gearwheel 62a, 62b uses two gearwheels in this Embodiment, However, You may use three or more gear trains. .

  As described above, since the shaft centers of the gears 62a and 62b are offset in the lateral direction, the shaft center of the motor 51 coupled to the gears 62a and 62b and the shaft center of the ball screw nut 4 are shifted in the lateral direction. As a result, the motor 51 is disposed in parallel to the side of the ball screw nut 4 outside the outer cylinder 65.

  Since the motor 51 is arranged on the side of the ball screw nut 4 by adopting the above configuration, it is not necessary to provide the motor 1 vertically above the screw shaft 3 unlike the conventional suspension device. In other words, by arranging the motor 51 in parallel with the outer cylinder 5, the stroke required for the shock absorber can be secured and the basic length can be shortened. That is, space saving can be achieved.

  In addition, although the motor 51 is arrange | positioned in the side vicinity of the ball screw nut 4, it is also possible to arrange | position the motor 51 in the position away from the ball screw nut 4 using the gear train as mentioned above. . Therefore, for example, it is possible to prevent the motor 51 from being damaged by rainwater, mud, stepping stones, etc. by arranging only the motor 51 in the vehicle body.

  Although not shown, the motor may be configured by attaching one of a magnet or a coil to the outer periphery of the ball screw nut 4 and attaching the other of the magnet or the coil to the housing 59. In this case, the gear mechanism can be eliminated.

  With the above configuration, the rotational movement of the ball screw nut 4 due to the linear movement of the screw shaft 3 in the vertical direction in FIG. 10 is transmitted to the shaft 51a of the motor 51 because the drive gear 62b and the driven gear 62a are engaged with each other. As a result, the motor 51 rotates, and the torque that resists the rotation of the shaft 51a caused by the electromagnetic force acts as a damping force that suppresses the rotation of the ball screw nut 4 via the gear mechanism.

  In the above description, the driving gear and the driven gear are horizontally arranged to transmit the rotational motion of the ball screw nut 4 to the motor 51. However, each gear is used as a bevel gear and the motor 51 is attached to the ball screw nut 4. It is also possible to change the angle. In this case, since the attachment angle can be adjusted, the suspension device according to the present invention can be attached according to the structure of the vehicle to be applied. Therefore, it is possible to attach the suspension device without being influenced by the layout of a new or existing vehicle. Further, any type of bevel gear may be used, but a helical bevel gear or the like capable of smooth transmission is preferable.

  Further, in order to transmit the rotational motion of the ball screw nut 4 to the shaft 51a of the motor 51, a friction wheel mechanism or a belt mechanism may be used in addition to the gear mechanism.

  When the suspension device configured in this manner expands and contracts, the screw shaft 3 exhibits a linear motion up and down in FIG. 10. This linear motion is converted into a rotational motion of the ball screw nut 4. The rotational movement of the screw nut 4 is transmitted to the shaft 51a through a gear mechanism. Therefore, the torque that resists the rotation of the shaft 51 a caused by the electromagnetic force generated by the motor 51 suppresses the rotation of the ball screw nut 4, and the action of suppressing the rotation of the ball screw nut 4 is the screw shaft 3. As a result, the suspension acts by acting as a damping force for suppressing the relative movement of the ball screw nut 4 and the screw shaft 3 in the axial direction, and by supplying current to the motor 51. The device can also be used as an actuator.

  Even in the modified example configured as described above, the above-described ECU 30 can perform self-diagnosis of the actuator function of the suspension device and self-diagnosis of vibration suppression characteristics, and the same effects as the above-described embodiment It is possible to play.

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

It is a longitudinal cross-sectional view of the suspension apparatus in one embodiment of this invention. It is a figure which shows the state which applied the active suspension to the vehicle. It is a flowchart which shows the procedure in which a self-diagnosis apparatus performs a self-diagnosis about the actuator function of a suspension apparatus. It is a figure which shows the relationship between an electric current and the rotation angle of the shaft of a motor. It is a figure which shows the relationship between the offset electric current and the rotation angle of the shaft of a motor. It is a conceptual diagram which shows an example of a stroke position detection means. It is a flowchart which shows the procedure in which a self-diagnosis apparatus obtains a vibration suppression characteristic graph. It is a vibration suppression characteristic graph which shows the relationship between a rotation angle and time. It is a flowchart which shows the procedure in which a self-diagnosis apparatus performs a self-diagnosis about the vibration suppression characteristic of a suspension apparatus. It is a longitudinal cross-sectional view of the suspension apparatus in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 Motor 1a, 51a Shaft 3 Screw shaft 3a Screw groove 4 Ball screw nut 30 Controller ECU
B1, B2, B3, B4 Car body side member D1, D2, D3, D4 Suspension device H Hall element K1, K2, K3, K4 Suspension spring S1, S2, S3, S4 Axle side member

Claims (7)

In an active suspension self-diagnosis device that is interposed between a vehicle body side member and an axle side member of a vehicle and can adjust the generated control force, the active suspension rotates the relative motion of the vehicle body side member and the axle side member. A suspension device that has a motion conversion mechanism for converting to a motor and a motor to which the rotational motion is transmitted, and uses an electromagnetic force generated in the motor as a control force that suppresses relative movement between the vehicle body side member and the axle side member. At the time of self-diagnosis, a graph showing the change in the rotation angle of the motor shaft or the relative displacement between the vehicle body side member and the axle side member with respect to the change in the current value or voltage value supplied to the motor is created. The normal relationship between the rotation angle of the motor shaft relative to the current value or voltage value supplied to Self-diagnosis apparatus of the active suspension and performing determination suspension system is normal by comparing the normal graph showing. 2. The active suspension self-diagnosis device according to claim 1, wherein when the deviation between the graph created during the self-diagnosis and the normal graph is within a predetermined standard, the suspension device is determined to be normal. The self-diagnosis device for an active suspension according to claim 1 or 2, wherein a normal graph is corrected based on a change in weight of the vehicle body at the time of self-diagnosis. Rotation angle of motor shaft over time after body vibration, relative displacement between body side member and axle side member, relative speed between body side member and axle side member, relative acceleration between body side member and axle side member, or body side The self-diagnosis of the active suspension according to any one of claims 1 to 3 , wherein self-diagnosis is performed based on a change in absolute displacement of the member, absolute velocity of the vehicle body side member, or absolute acceleration of the vehicle body side member. apparatus. Rotation angle of motor shaft over time after body vibration, relative displacement between body side member and axle side member, relative speed between body side member and axle side member, relative acceleration between body side member and axle side member, or body side 5. The self-diagnosis device for an active suspension according to claim 4 , wherein when the absolute displacement of the member, the absolute velocity of the vehicle body side member, or the absolute acceleration of the vehicle body side member is within a predetermined reference, the suspension device is determined to be normal. . The rotation angle of the motor shaft or the relative displacement between the vehicle body side member and the axle side member or the relative speed between the vehicle body side member and the axle side member or the relative acceleration between the vehicle body side member and the axle side member due to the passage of time after the vehicle body vibration during self-diagnosis. Alternatively, a graph showing the absolute displacement of the vehicle body side member, the absolute speed of the vehicle body side member, or the absolute acceleration of the vehicle body side member is created, and this graph and the rotation angle of the motor shaft or the vehicle body over time after vibration of the vehicle body Relative displacement between the side member and the axle side member, or the relative speed between the vehicle body side member and the axle side member, the relative acceleration between the vehicle body side member and the axle side member, the absolute displacement of the vehicle body side member, the absolute speed of the vehicle body side member, or the vehicle body side member Accession of claim 5, normal changes in absolute acceleration by comparing the graph of performing determination suspension device is normal Self-diagnosis system of I blanking suspension. Control power to supply current or voltage to the motor during self-diagnosis to cancel the rotation angle of the motor shaft due to the vehicle body weight change amount, and to cancel the sprung vibration frequency change and damping rate change due to the vehicle body weight change to the suspension device The self-diagnosis device for an active suspension according to claim 6 , wherein

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