The invention relates generally to an air suspension system having the ability to automatically raise or lower the ride height of the vehicle based on one or more of external signals and internal signals available to the vehicle.
Suspension systems for automotive vehicles provide vehicle passengers with a more comfortable ride. Air suspension systems utilize air springs, rather than traditional coil springs, and provide different suspension qualities that may be preferable to traditional coil spring suspensions in some vehicles.
A conventional air spring is a device that is arranged between a vehicle body and chassis. The typical air spring has at least one working space, or cavity that is filled with compressed air generated by a compressor. The cavity filled with compressed air at least partially fills a bellow, and other surrounding cavities. There are also air suspension systems in which the air pressure is adjustable such that the ride height of the vehicle and the spring rate of each air spring may be adjusted. Some air suspension systems are used with vehicles having off-road capability. These off-road vehicles often operate under conditions where the suspension jounce is maximized, and the pressure in each air spring increases during compression travel. Other instances where it may be beneficial to increase the ride height of the vehicle include traveling up or down steep ramps in a parking garage. There are also situations where it may be beneficial to lower the ride height of the vehicle, such as when the vehicle is entering a parking garage having a low ceiling height, or when the driver or passengers are entering and exiting the vehicle.
Many vehicles include some type of controller or actuator device which may be used by the driver to control the aft suspension system, and therefore control the ride height of the vehicle. However, pushing buttons or adjusting a knob while driving may result in distraction of the driver, and increase the risk of a collision. Furthermore, there may be situations where the driver is unaware that the height of the vehicle may need to be adjusted, such as the ceiling of a parking garage being too low for the vehicle to pass through without the ride height being lowered.
Accordingly, there exists a need for an air suspension system which automatically adjusts the ride height of the vehicle based on input from various devices, without input from the driver of the vehicle.
In one embodiment, the present invention is an air suspension system which uses software logic and internal signals and/or external signals available to the vehicle to automatically adjust the ride height of the vehicle. The air suspension system also may respond to requests from other vehicle systems requesting a change in ride height. Examples of these other vehicle systems include, but are not limited to, ADAS, EBS, etc.
In one embodiment, the present invention uses the signals available to the vehicle, such that the air suspension system is able to detect parking lot maneuvers (for example, a combination of low speed, high steering angle, and low lateral acceleration) and automatically begin to lower the ride height of the vehicle to a calibrated “entry/exit” ride height.
In another embodiment, a camera, radar, and/or parking sensor signals are utilized to detect potential roof or undercarriage clearance issues, and automatically adjust the ride height of the vehicle. Examples of this embodiment include, but are not limited to, a vehicle driving into a garage that has low clearance, or a vehicle with low ground clearance going over a speed bump.
In yet another embodiment, the air suspension system adjusts the ride height of the vehicle based on calculated signals, such as when electronic brake system (EBS) detects rough road, the air suspension system automatically increases the ride height of the vehicle to increase ground clearance.
In one embodiment, the present invention is an air suspension system for a vehicle, where the air suspension system includes a control unit, a compressor in electrical communication with the control unit, and a plurality of air spring assemblies. The air suspension system also includes at least one camera in electrical communication with the control unit, at least one radar device in electrical communication with the control unit, and at least one sensor in electrical communication with the control unit. The ride height of the vehicle may be adjusted based on the input, which may correspond to the operation of the vehicle, such as vehicle speed, changes in steering angle, lateral acceleration, and braking.
The ride height of the vehicle may also be adjusted based on feedback from one or more of the camera, radar device, or the sensor. In one configuration, the ride height of the vehicle is decreased to facilitate entry and exit of the vehicle. In another configuration, the ride height of the vehicle is decreased to facilitate avoidance of a collision with the roof of a parking structure. In yet another configuration, the ride height of the vehicle is increased to facilitate avoidance of a collision between the undercarriage of the vehicle and a speed bump.
In one embodiment, the vehicle includes an electronic braking system, and the ride height of the vehicle is adjusted based on input from the electronic braking system. More specifically, in one configuration, the ride height of the vehicle is increased to facilitate the vehicle traversing a rough section of a road, such as a gravel road having rough terrain.
The air suspension system may also be used to lower the ride height of the vehicle based on other commands from the EBS system, such as when the vehicle is performing an extreme maneuver, such as an anti-lock brake system (ABS) event, or when oversteer or understeer has occurred. In this instance, the ride height of the vehicle may be lowered to increase the stability of the vehicle.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
A chassis of a vehicle having an air suspension system according to the present invention is shown in
Referring now to
The control unit 18 may also receive various input based on how the driver is operating the vehicle, represented at 30. This vehicle operational input 30 may include, but is not limited to, vehicle speed, steering angle, lateral acceleration, and braking. There is also a switch 32 which is in electrical communication with the control unit 18, where the switch may be used by the driver to manually adjust the ride height of the vehicle.
During travel of the vehicle, the air compressor 14 and the air spring assemblies 18A-18D are used to adjust the ride height of the vehicle, to provide the desired ride quality, or adapt to various driving conditions.
The air suspension system 10 is used to automatically adjust the ride height of the vehicle, without direct driver input (i.e., without the use of the switch 32). One example of this is shown in
Another example use of the air suspension system 10 of the present invention is shown in
There may be other situations where the ride height of the vehicle may need to be increased, so as to avoid a collision with a speed bump. Referring to
Another example of use of the air suspension system 12 is shown in
The air suspension system 12 may also be used to lower the ride height H of the vehicle 34 based on other commands from the EBS system 28, such as when the vehicle 34 is performing an extreme maneuver, such as an anti-lock brake system (ABS) event, or when oversteer or understeer has occurred. In this instance, the ride height H of the vehicle 34 may be lowered to increase the stability of the vehicle 34.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.