JP2006161881A - Vehicle suspension device, vehicle control device and vehicle control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for properly controlling a vehicle body while reducing power consumption. <P>SOLUTION: An electromagnetic suspension 4 provided on each wheel 3 of a vehicle 1 has an electric power generating means for generating electric power using relative vibration of the vehicle body between the upper and lower parts of a spring. The electric power generated by the electric power generating means with the up-and-down vibration of the vehicle body due to road surface input is supplied via a wire harness 11 to an acceleration sensor 6 which detects the acceleration of the up-and-down vibration. The detection result of the acceleration sensor 6 is transmitted to an ECU 10 to control the vehicle body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle suspension device, and in particular, a vehicle suspension device including a power generation unit that generates electric power using relative vibration between a sprung and unsprung portion of a vehicle, a vehicle control device that can use the vehicle suspension device, and The present invention relates to a vehicle control method.

A vehicle shock absorber (shock absorber) that uses an electrical load to generate a damping force has been proposed (see, for example, Patent Document 1). In the shock absorber disclosed in Patent Document 1, a coil is wound in a cylinder, a piston having a magnet attached to the coil is slidably inserted, and the cylinder and the piston are connected to a wheel and a vehicle body, respectively. Connect an electrical load to When the piston slides due to the vibration of the vehicle body, electric energy is generated in the coil by the electromagnetic action between the coil and the magnet, and the battery is charged by the generated energy, thereby electrically braking the piston against sliding. (So-called regenerative braking) is generated, and thereby a damping force is generated. Furthermore, control means is provided for controlling the amount of power generated in the coil so that the electric braking force can be varied in accordance with the traveling state of the traveling vehicle. Thereby, an accurate damping force can be obtained according to various traveling conditions. Here, in order to determine the traveling state of the traveling vehicle, an acceleration sensor that detects acceleration in the vertical direction of the vehicle is generally used.
Japanese Patent Laid-Open No. 5-131832 Japanese Patent Laid-Open No. 3-98455 JP-A-4-129815 JP-A-8-58334 JP-A-11-65679 JP 2002-48189 A

  Conventionally, the acceleration sensor is always supplied with power from a battery, etc., and continues to operate and consume power even when there is almost no vertical acceleration, such as when the vehicle is stopped or driving on a good road. is doing. The present inventor considered that there is room for improvement in the method of supplying power to the acceleration sensor from the viewpoint of reducing power consumption, and came to conceive the present invention.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which controls a vehicle appropriately, reducing power consumption.

  One embodiment of the present invention relates to a vehicle suspension apparatus. The vehicle suspension device is disposed between a spring and an unspring of the vehicle, and an absorber for damping the vibration on the spring and the unspring, and power generation according to the vibration on the spring and the unspring. Power generation means for supplying the power generated by the power generation means to an acceleration sensor for detecting acceleration on the spring or unsprung. By using the power generated by the power generation means, the power consumption of the main battery can be reduced.

  The vehicle suspension device may further include an electric actuator that contributes to control of the absorber, and the electric actuator may function as the power generation means. As a result, power generation can be performed while actively controlling the damping force between the sprung and unsprung parts using the electric actuator. The vehicle suspension device may further include a ball screw and a ball screw nut for converting the vertical vibration between the sprung and unsprung portions into a rotational force. The vehicle suspension device may further include a magnet provided on one of the sprung and unsprung portions and a coil provided on the other. In this case, a current is generated in the coil by electromagnetic induction in accordance with the relative vibration between the magnet and the coil, and the current may be supplied to the acceleration sensor. The acceleration sensor may operate substantially only with electric power supplied from the power generation means.

  Another aspect of the present invention relates to a vehicle control device. The vehicle control device is disposed between a sprung and unsprung portion of a vehicle, and an absorber for attenuating vibrations on the sprung and unsprung, and power generation according to vibrations on the sprung and unsprung. Power generation means, an acceleration sensor for detecting the unsprung or unsprung acceleration, and a control means for controlling the posture of the vehicle body by obtaining a detection result by the acceleration sensor, the acceleration sensor When the sprung and unsprung vibrations are generated, the acceleration is detected by operating with the power supplied from the power generation unit, and the control unit acquires the detection result from the acceleration sensor. The vehicle body posture is controlled. With such a configuration, it is possible to perform appropriate vehicle attitude control while reducing power consumption.

  Yet another embodiment of the present invention relates to a vehicle control method. This vehicle control method is an acceleration sensor for detecting the vertical acceleration of the spring or the unsprung direction when the power generation means that generates power by the relative vibration between the sprung and unsprung of the vehicle generates power. And the acceleration sensor is operated.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which controls a vehicle appropriately can be provided, reducing power consumption.

  In the embodiment, the vehicle suspension device is provided with a power generation means capable of generating electric power using relative vibration between the sprung and unsprung bodies of the vehicle body, and the power generation means according to the vertical vibration of the vehicle body due to road surface input or the like We propose a technique for supplying the electric power generated by the sensor to an acceleration sensor that detects the acceleration of vertical vibration.

(First embodiment)
FIG. 1 shows a configuration of a vehicle 1 according to a first embodiment of the present invention. The vehicle 1 includes a vehicle body 2, a wheel 3a that is a left front wheel, a wheel 3b that is a right front wheel, a wheel 3c that is a left rear wheel, and a wheel 3d that is a right rear wheel (hereinafter collectively referred to as "wheel 3" as appropriate). Prepare. The wheel 3 is composed of a wheel and a rubber tire. The vehicle body 2 and the wheels 3 are connected to each other via an electromagnetic suspension that is an example of a vehicle suspension device that includes an absorber that generates an unsprung and unsprung damping force of the vehicle 1 using an electric actuator. The position of the member supported by the spring of the electromagnetic suspension is referred to as “sprung”, and the position of the member not supported by the spring is referred to as “unsprung”. That is, the sprung is on the vehicle body 2 side, and the unsprung is on the wheel 3 side. In this example, the wheel 3a is attached to the electromagnetic suspension 4a, the wheel 3b is attached to the electromagnetic suspension 4b, the wheel 3c is attached to the electromagnetic suspension 4c, and the wheel 3d is attached to the electromagnetic suspension 4d. Hereinafter, the electromagnetic suspensions 4a, 4b, 4c, and 4d are collectively referred to as “electromagnetic suspension 4”. Each electromagnetic suspension 4 is independently controlled by an electronic control device (hereinafter, the electronic control device is referred to as “ECU”) 10. The ECU 10 includes a CPU, a RAM, a ROM, and the like.

  The current flowing through the electric actuator of the electromagnetic suspension 4 is detected by a current sensor. A current sensor 5a is provided for the electromagnetic suspension 4a, a current sensor 5b is provided for the electromagnetic suspension 4b, a current sensor 5c is provided for the electromagnetic suspension 4c, and a current sensor 5d is provided for the electromagnetic suspension 4d. Hereinafter, the current sensors 5a, 5b, 5c, and 5d are collectively referred to as “current sensor 5”. The detection result of each current sensor 5 is transmitted to the ECU 10. The current detection function by the current sensor 5 may be realized by the ECU 10.

  By providing the electromagnetic suspension 4 for each wheel 3, the ECU 10 can independently control the current applied to the electric actuator of the electromagnetic suspension 4 according to the state of each wheel 3. Further, by adopting the electromagnetic suspension 4, it is possible to realize control with excellent responsiveness.

  In order to appropriately control the posture of the vehicle body 2, the vehicle 1 is provided with an acceleration sensor for detecting the acceleration of the vehicle. In the present embodiment, an acceleration sensor 6a is provided near the wheel 3a, an acceleration sensor 6b is provided near the wheel 3b, an acceleration sensor 6c is provided near the wheel 3c, and an acceleration sensor 6d is provided near the wheel 3d. Yes. Hereinafter, the acceleration sensors 6a, 6b, 6c, and 6d are collectively referred to as “acceleration sensor 6”. Information on the acceleration detected by the acceleration sensor 6 is transmitted to the ECU 10 and used for controlling the posture of the vehicle body 2. The acceleration sensor 6 may be provided on the spring, may be provided below the spring, or may be provided on both. In the example of FIG. 1, the acceleration sensor 6 is provided for each wheel 3, but the number of the acceleration sensors 6 may be one or more as necessary. As will be described later, the electric power necessary for the operation of the acceleration sensor 6 is supplied from the electromagnetic suspension 4 via the wire harness 11.

  FIG. 2 shows the configuration of the electromagnetic suspension 4. The electromagnetic suspension 4 includes an electric actuator 20, a ball screw 24, a ball screw nut 26, a rod 28, an outer shell 30, bearings 32, 34 and 36, a dust seal 38 and a rotation angle sensor 44, and an unsprung portion. A coil spring 22 elastically supported on the spring and an upper support 70 for coupling the shock absorber 80 to the vehicle body 2 are provided. The bearing 32 rotatably supports the ball screw 24 inside the rod 28, and the bearings 34 and 36 support the rod 28 slidably inside the outer shell 30. The dust seal 38 prevents foreign matters such as dust from entering the outer shell 30. The rotation angle sensor 44 detects the amount of rotation of the electric actuator 20. The detection result of the rotation angle sensor 44 is transmitted to the ECU 10. The rotation angle sensor 44 may be provided outside the electric actuator 20 or may be provided inside the electric actuator 20. The electromagnetic suspension 4 is attached to the configuration on the vehicle body 2 side at the first attachment portion 40, and is attached to the configuration on the wheel 3 side at the second attachment portion 46. The coil spring 22 is contracted between the body surface in the vicinity of the first mounting portion 40 and the spring seat 42, and is given a predetermined load in advance.

  The coil spring 22 supports the weight of the sprung portion of the vehicle 1 and prevents vibrations and shocks from the road surface from being transmitted to the vehicle body 2 through the wheels 3. The shock absorber 80 attenuates the vertical vibration of the vehicle body 2 caused by the coil spring 22. The shock absorber 80 can generate a damping force between the sprung and unsprung parts of the vehicle 1 using the electric actuator 20, and has excellent control response.

  The ball screw 24, the rod 28 and the outer shell 30 are arranged coaxially. The outer shell 30 is internally provided with a ball screw nut 26 having a female screw portion. The ball screw 24 has a male screw portion and is in a state of being screwed into the ball screw nut 26. The electric actuator 20 is an electric motor, and supports one end of the ball screw 24 by serration so as to be rotatable. When the electric actuator 20 is driven, the ball screw 24 rotates relative to the ball screw nut 26, and the outer shell 30 is pushed downward or lifted upward with respect to the electric actuator 20. In this embodiment, an example in which the ball screw 24 is provided on the vehicle spring and the ball screw nut 26 is provided below the vehicle spring will be described. Conversely, the ball screw 24 is provided below the vehicle spring. A screw nut 26 may be provided on the spring of the vehicle.

  When the vehicle 1 is traveling on a good road, the ECU 10 sets the current value applied to the electric actuator 20 of each electromagnetic suspension 4 to a reference current value of, for example, 0A. When the road surface is uneven and the wheel 3 moves up and down, the coil spring 22 expands and contracts due to the relative movement between the rod 28 and the outer shell 30. At this time, when the ball screw 24 rotates relative to the ball screw nut 26, the electric actuator 20 rotates and acts as a generator, and a damping force is generated by the resistance force generated at this time. The current sensor 5 detects a current generated by electromagnetic induction inside the electric actuator 20 and transmits it to the ECU 10. The ECU 10 applies to the electric actuator 20 a current in a direction that suppresses expansion and contraction of the coil spring 22, that is, a current that is opposite to the current generated by electromagnetic induction. ECU10 sets the electric current applied to the electric actuator 20 according to the acceleration of the up-down direction of the vehicle body 2, and adjusts damping force. Thus, the shock absorber 80 of the present embodiment functions as an electromagnetic shock absorber. Further, since the vehicle body 2 can be displaced in the vertical direction by rotating the ball screw 24, the shock absorber 80 of the present embodiment can be used for controlling the posture of the vehicle body 2.

  The electric actuator 20 functions as a power generation unit that generates electric power according to the relative vibration between the sprung and unsprung parts. In the present embodiment, when the sprung and unsprung parts vibrate due to road surface input or the like, the electric power generated in the electric actuator 20 is supplied to the acceleration sensor 6 via the wire harness 11 or the like. Thereby, the acceleration sensor 6 operates and acceleration can be detected. When the ECU 10 acquires the detection result from the acceleration sensor 6, the ECU 10 uses the information to control the posture of the vehicle body, such as controlling the current applied to the electric actuator 20. The electric power necessary for the operation of the acceleration sensor 6 may be supplied substantially only from the electric actuator 20.

  3A and 3B show examples of acceleration sensors. FIG. 3A shows the top surface of the acceleration sensor 6, and FIG. 3B shows the front surface of the acceleration sensor 6. The acceleration sensor 6 is provided with an output terminal 7 for outputting a detection result, a power supply terminal 8, and a ground terminal 9. The output terminal 7 is connected to the ECU 10. The power terminal 8 is connected to the electric actuator 20 of the electromagnetic suspension 4 via the wire harness 11 or the like. While electric power is supplied from the electric actuator 20 via the power supply terminal 8, the acceleration sensor 6 outputs a detection result from the output terminal 7.

  FIG. 4 is a flowchart showing the procedure of the vehicle control method according to the present embodiment. When the sprung and unsprung parts relatively vibrate up and down due to road surface input or the like, electric power is generated in the electric actuator 20 of the electromagnetic suspension 4 using the vibration (S10). This electric power is supplied to the acceleration sensor 6 via the wire harness 11 or the like (S12). The acceleration sensor 6 operates using this electric power, detects the acceleration in the vertical direction of the vehicle body, and transmits it to the ECU 10 (S14). The ECU 10 controls the posture of the vehicle body based on the detected acceleration (S16).

(Second Embodiment)
FIG. 5 shows a configuration of the electromagnetic suspension 4 according to the second embodiment. The electromagnetic suspension 4 of this embodiment does not include the ball screw 24 and the ball screw nut 26 as compared with the electromagnetic suspension 4 of the first embodiment shown in FIG. A magnet 50 is attached to the shell 30, and a coil 52 is wound around the rod 28. The overall configuration of the vehicle 1 of the second embodiment is the same as the overall configuration of the vehicle 1 of the first embodiment shown in FIG.

  When the outer shell 30 vibrates with respect to the rod 28 due to road surface input or the like, the magnet 50 moves up and down accordingly. At this time, since the magnetic field changes, a current is generated in the coil 52 due to electromagnetic induction. This current is supplied to the acceleration sensor 6 through the wire harness 11. That is, the magnet 50 and the coil 52 function as power generation means. Other configurations and operations are the same as those in the first embodiment.

  As described above, according to the embodiment, since the acceleration sensor can operate substantially only with the power from the power generation means, it is not necessary to supply power to the acceleration sensor from a battery or the like, and the power consumption of the battery Can be reduced. In addition, power consumption can be further reduced by supplying power to the acceleration sensor to operate it only when it is necessary to detect acceleration. It is necessary to detect the acceleration when acceleration is generated in the vertical direction. At that time, power should be generated by the power generation means, so if power is detected and acceleration is detected Good. Thereby, electric power can be used efficiently. Further, when acceleration occurs in the vertical direction, electric power is generated by the power generation means, the acceleration sensor is operated by the electric power, and information on the acceleration is transmitted to the ECU. Therefore, the ECU may start the control of the vehicle body when information on acceleration is transmitted from the acceleration sensor.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

It is a figure which shows the structure of the vehicle which concerns on 1st Embodiment. It is a figure which shows the structure of an electromagnetic suspension. FIG. 3A is a diagram illustrating the top surface of the acceleration sensor, and FIG. 3B is a diagram illustrating the front surface of the acceleration sensor. It is a flowchart which shows the procedure of the vehicle control method which concerns on 1st Embodiment. It is a figure which shows the structure of the electromagnetic suspension which concerns on 2nd Embodiment.

Explanation of symbols

  1 vehicle, 2 vehicle body, 3 wheel, 4 electromagnetic suspension, 5 current sensor, 6 acceleration sensor, 10 ECU, 11 wire harness, 20 electric actuator, 24 ball screw, 26 ball screw nut, 28 rod, 30 outer shell, 50 magnet , 52 coils, 80 shock absorbers.

Claims (5)

An absorber disposed between the sprung and unsprung parts of the vehicle for damping vibrations on the sprung and unsprung;
Power generation means for generating electric power in response to vibrations on the spring and the unsprung,
A vehicle suspension apparatus, wherein power generated by the power generation means is supplied to an acceleration sensor for detecting acceleration on the spring or unsprung. An electric actuator that contributes to the control of the absorber;
The vehicle suspension device according to claim 1, wherein the electric actuator functions as the power generation means.   The vehicle suspension apparatus according to claim 1 or 2, wherein the acceleration sensor operates substantially only with electric power supplied from the power generation means. An absorber disposed between the sprung and unsprung parts of the vehicle for damping vibrations on the sprung and unsprung;
Power generation means for generating power in response to vibrations on the spring and unsprung;
An acceleration sensor for detecting the unsprung or unsprung acceleration;
Control means for acquiring the detection result by the acceleration sensor and controlling the posture of the vehicle body,
The acceleration sensor detects the acceleration by operating with electric power supplied from the power generation means when vibrations on the spring and under the spring occur.
The vehicle control apparatus, wherein the control means controls the posture of the vehicle body when a detection result is acquired from the acceleration sensor.   When power generation means that generates power by relative vibration between the spring and unspring of the vehicle generates power, the power is supplied to an acceleration sensor for detecting vertical acceleration on the spring or unspring, and the acceleration A vehicle control method comprising operating a sensor.

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