US 5,301,111 A · Suspension apparatus for a vehicle

Abstract

An improved support apparatus such as a suspension apparatus for a vehicle is disclosed which has excellent response characteristics, can save power consumption and has excellent vibration-isolating capacity for isolating the transmission of high-frequency vibrations from a support member such as a road wheel to an object such as the body of a vehicle. To these end, in one embodiment, a linear motor is disposed between the object and the support member for telescopically supporting the object under magnetic effects. A position sensor senses the position of the object relative to a reference position. A low-pass filter filters high-frequency components of the output signal of the position sensor above a prescribed upper frequency limit. Based on the output signals of the position sensor and the low-pass filter, the current supply to the linear motor is controlled in such a manner as to offset a change in the output signal of the low-pass filter. In another embodiment, an elastic member is further disposed between the object and the support member in parallel with the linear motor for elastically supporting the object on the support member. A high-pass filter filters low-frequency components of the output signal of the position sensor below a prescribed lower frequency limit. Based on the output signal of the high-pass filter, a correction is calculated for offsetting a change in the operating force of the elastic member. The current supply to the linear motor is controlled based on a change in the output signal of the low-pass filter and the correction thus calculated.

Claims8

Dependent claims

A support apparatus for dampingly supporting an object on a support member, said support apparatus comprising:

a linear motor disposed between said object and said support member for telescopically supporting said object under magnetic effects, said linear motor having a stator member and a movable member which is movable relative to said stator member, said movable member being magnetically connectable with said stator member, one of said stator member and said movable member being connected to said object, the other of said stator member and said movable member being connected to said support member;
a position sensor for sensing the position of said object relative to a reference position and generating an output signal representative of the sensed relative position of said object;
height control means including a low-pass filter, coupled to said position sensor, for filtering high-frequency components of the output signal of said position sensor that are above a prescribed upper frequency limit;
vibration isolating means including a high-pass filter, coupled to said position sensor, for filtering low-frequency components of the output signal of said position sensor that are below a prescribed lower frequency limit;
sensing means for sensing various conditions of said object;
attitude control means, responsive to said sensing means, for calculating a target object height or attitude;
and
current control means, coupled to said height control means, vibration isolating means, and attitude control means, for controlling, based on output signals of said low-pass filter and high-pass filter, the current supply to said linear motor in such a manner as to offset a change in said output signal of said low-pass filter so as to maintain said target object height or attitude, and a change in said output signal of said high-pass filter so as to compensate for non-controlled high-frequency vibrations of said object.

5 more elements

A suspension apparatus for a vehicle for dampingly supporting a vehicle body on a road wheel, said suspension apparatus comprising:

a linear motor disposed between said vehicle body and said road wheel for telescopically supporting said vehicle body under magnetic effects, said linear motor having a stator member and a movable member which is movable relative to said stator member for telescopic movement, said movable member being magnetically connectable with said stator member, one of said stator member and said movable member being connected to said vehicle body, the other of said stator and said movable member being connected to said road wheel;
an elastic member disposed between said vehicle body and said road wheel in parallel with said linear motor for elastically supporting said vehicle body on said road wheel;
first sensor means for sensing the various dynamic conditions of said vehicle body comprising a height sensor for sensing the height of said vehicle body relative to said road wheel;
second sensor means for sensing the various operating conditions of said road wheel;
and
control means for controlling the current supply to said linear motor based on the output signals from said first and second sensor means in such a manner that said linear motor operates to isolate the transmission of high-frequency vibrations of said road wheel to said vehicle body while maintaining the height of said vehicle body at a target level, said control means comprising:
a low-pass filter for filtering high-frequency components of the output signal of said height sensor above a prescribed upper frequency limit;
a high-pass filter for filtering low-frequency components of the output signal of said height sensor below a prescribed lower frequency limit;
correction calculating means for calculating, based on the output signal of said high-pass filter, a correction for offsetting a change in the operating force of said elastic member;
attitude control means for calculating a height control value representative of a target vehicle height based on the output signals from said first and second sensors means;
an adder for adding the correction from said correction calculating means and the height control value from said attitude control means, and generating an output signal representative of the result of the addition;
and
current control means for controlling the current supply to said linear motor based on the output of said low-pass filter, the output of said adder and the output of said height sensor.

10 more elements

A suspension apparatus for a vehicle for dampingly supporting a vehicle body on road wheels, said suspension apparatus comprising:

a plurality of linear motors each disposed between said vehicle body and one of said road wheels for telescopically supporting said vehicle body under magnetic effects, said linear motor having a stator member and a movable member which is movable relative to said stator member for telescopic movement, said movable member being magnetically connectable with said stator member, one of said stator member and said movable member being connected to said vehicle body, the other of said stator and said movable member being connected to said corresponding road wheel;
a plurality of elastic members each disposed between said vehicle body and one of said road wheels in parallel with a corresponding one of said linear motors for elastically supporting said vehicle body on the corresponding road wheel;
a plurality of height sensors provided one for each road wheel for sensing the height of said vehicle body relative to the corresponding road wheel;
first sensor means for sensing the dynamic conditions of said vehicle body;
second sensor means for sensing the various operating conditions of the vehicle;
and
vehicle-attitude control means for generating, based on the output signals of said first and second sensor means, vehicle-attitude control signals representative of a target attitude of said vehicle body relative to said road wheels;
thrust control means for controlling the thrust of each of said linear motors based on the output signals from said height sensors and said vehicle-attitude control means in such a manner that each of said linear motors operates to isolate the transmission of high-frequency vibrations of the corresponding road wheel to said vehicle body while maintaining the attitude of said vehicle body at the target attitude;
and
current control means for controlling the current supply to said respective linear motors based on the output signals from said thrust control means.

7 more elements

Dependencies are inferred from the claim text.

Suspension apparatus for a vehicle

Life of this patent

Suspension apparatus for a vehicle

Life of this patent

Abstract

Claims8