AU2017100911A4 - An active pneumatic suspension of a vehicle - Google Patents
An active pneumatic suspension of a vehicle Download PDFInfo
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- AU2017100911A4 AU2017100911A4 AU2017100911A AU2017100911A AU2017100911A4 AU 2017100911 A4 AU2017100911 A4 AU 2017100911A4 AU 2017100911 A AU2017100911 A AU 2017100911A AU 2017100911 A AU2017100911 A AU 2017100911A AU 2017100911 A4 AU2017100911 A4 AU 2017100911A4
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- pneumatic suspension
- displacement
- support member
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Abstract
AN ACTIVE PNEUMATIC SUSPENSION OF A VEHICLE The present invention relates to an active pneumatic suspension system which enhances the ride quality and comfort of a vehicle user and/or that effectively isolates the precision instruments, thereby improving accuracy of the precision instruments. The present invention is simple and economic. 102b 110b 102a 2.5 ------------ -------------------------------------- 2 ------ ------ --- - ---------------------- ----- 9i2I 1. ---- --- ---------- ----------- -----------------------1---- -------- -- ------------- ----------- ------------0.5 -------- -- --- ------------- ------------------------ 0 1 2 3 4 5 Frequency
Description
2017100911 03 Μ 2017
FIELD OF THE INVENTION
The present invention relates to a suspension system and in particular to an active pneumatic suspension system.
BACKGROUND OF THE INVENTION
An important component of any vehicle is its suspension. The wheels of a vehicle are secured to the body via the suspension, wherein the suspension aids in isolating the vehicle itself, the occupants’ and any other cargo or luggage from the bumps, and vibrations received from the wheel owing to uneven road surface during the course of its movement over the road, whereby discomfort to the occupants and damage or wear of the vehicle and/or cargo or luggage is avoided or reduced considerably.
Similarly, for precision instruments, particularly those used in calibration laboratories, it is essential to isolate the precision instruments from ground vibrations, failing which the accuracy of the precision instruments is hampered/reduced. The precision instruments are also isolated using suspensions, which may be similar to those used in vehicles.
Numerous types of suspension systems have been devised to enhance the ride quality and comfort of a user riding the vehicle and/or for isolating the precision instruments. 2017100911 03 Μ 2017
One such conventional suspension system that has been devised is the pneumatic suspension system. A typical conventional pneumatic suspension system comprises a flexible fluid cylinder suitably secured to a wheel of the vehicle and the vehicle body, and a compressed fluid source, which is connected to and in fluid communication with the flexible fluid cylinder via a control valve, wherein the compressed fluid source is capable of providing pressurized fluid to the flexible fluid cylinder via the control valve, which is configured to control the mass flow rate of the fluid to and from the flexible fluid cylinder. The control valve may be actuated mechanically and/or electrically, whereby the pressure and/or stiffness of the flexible fluid cylinder can be controlled to a suitable value, which results in reduction of the vibrations that reach and/or are transmitted to the vehicle body due to excitation of the wheels, thereby enhancing the ride quality and comfort.
Similar configuration of the pneumatic suspension system, as described hereinabove with reference to vehicle, may be utilized for precision instruments, wherein instead of coupling the pneumatic suspension system to the wheel and the vehicle body, it is coupled between a support that holds the precision instrument and ground.
In one known conventional pneumatic suspension system, there is no 2 of 16 feed back mechanism and the mass flow rate of the fluid is not at all controlled. This is referred to as passive pneumatic suspension system. 2017100911 03 Μ 2017
In another known conventional pneumatic suspension system, the mass flow rate of the fluid to and from the flexible fluid cylinder is controlled by controlling the control valve opening, which may be some function of wheel movement/excitation. The suspension system may further include dampers and/or force actuators in addition to the above-mentioned components to reduce the vibrations and achieve a smooth ride.
However, there are certain drawbacks associated with the above-mentioned conventional pneumatic suspension systems. For example, the conventional pneumatic suspension systems include some type of adjustable dampers or force actuators, in addition to the above mentioned components, thereby making them complicated, for use and fabrication, and are expensive.
Hence, there is a need to provide a pneumatic suspension system, which overcomes the drawbacks of the conventional pneumatic suspension systems.
OBJECTS OF THE INVENTION
Some of the objects of the presently disclosed invention, of which at the minimum one embodiment herein fulfills, are as follows: 3 of 16
An object of the present invention is to remove or reduce one or more deficiencies encountered in the prior art or to at the minimum deliver a beneficial substitute; 2017100911 03 Μ 2017
Another object of the present invention is to provide a pneumatic suspension system;
Still another object of the present invention is to provide a pneumatic suspension system that provides enhanced ride quality and comfort to the user;
Yet another object of the present invention is to provide a pneumatic suspension system that effectively isolates the precision instruments, thereby improving accuracy of the precision instruments; and
Still another object of the present invention is to provide a pneumatic suspension system that is simple and economic.
Other objects and benefits of the present invention will be more apparent from the following description, which is not intended to bind the scope of the present invention.
SUMMARY OF THE INVENTION
The present invention relates to an active pneumatic suspension system which enhances the ride quality and comfort of a vehicle user 4 of 16 and/or that effectively isolates the precision instruments, thereby improving accuracy of the precision instruments. 2017100911 03 Μ 2017
In accordance with an embodiment of the present invention, the active pneumatic suspension system comprises: a pneumatic suspension assembly comprising a pneumatic suspension unit, the pneumatic suspension assembly having a first operative end and a second operative end, the pneumatic suspension assembly is suitably secured to a first support member at the first operative end and a second support member at the second operative end; a first displacement sensor, suitably disposed on the first support member, for detecting displacement in a vertical direction of the first support member and generating a first displacement signal; and a second displacement sensor, suitably disposed on the second support member, for detecting displacement in vertical direction of the second support member and generating a second displacement signal.
In accordance with the presently disclosed invention, the active pneumatic suspension system further comprises: 5 of 16 an analog to digital converter cooperating with each of the first and the second displacement sensors and are configured to receive the first and the second displacement signals and convert the first and second displacement signals to first and second digitized displacement signals respectively; 2017100911 03 Μ 2017 a memory for receiving and storing the first and second digitized displacement signals received from the analog to digital converter; a processor communicatively coupled with the memory and configured to receive the first and second digitized displacement signals stored in the memory; wherein the processor is configured to compute: a difference between the first and second digitized displacement signals to obtain a difference digitized displacement signal; and a first differential of the difference digitized displacement signal with respect to time to obtain a velocity signal corresponding to each value of the digitized displacement signal; and further reverse the phase of the velocity signal to 6 of 16 obtain a phase reversed velocity signal. 2017100911 03 Μ 2017
Further, a compressed air source is provided for charging and discharging air under pressure via a control valve to and from said pneumatic suspension unit.
The charging and discharging of air from the compressed air source is controlled by a controller, wherein the controller is communicatively coupled with the processor and configured to generate a valve control signal responsive to the phase reversed velocity signal received from the processor, wherein the control valve is responsive to the valve control signal for controlling charging and discharging of air to and from the pneumatic suspension unit, thereby facilitating control of pressure inside the pneumatic suspension unit to a predetermined value, which in turn alters the stiffness value of the pneumatic suspension unit.
Typically, the suspension unit is a bellow type suspension unit.
Typically, the compressed air source is at least one selected from the group consisting of an air compressor, and a compressed air tank.
Typically, the phase of the velocity signal is reversed by 180°.
Typically, the first and second displacement sensors are at least one sensor independently selected from the group consisting of Linear variable differential transformers (LVDT) and accelerometers. 7 of 16
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING 2017100911 03 Μ 2017
The present invention will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a block diagram of an active pneumatic suspension system in accordance with an embodiment of the presently disclosed invention; and
Figure 2 illustrates a graph of transmissibility versus frequency of vibrations for conventional pneumatic system and active pneumatic system in accordance with an embodiment of the presently disclosed invention.
DETAILED DESCRIPTION
The inventors of the present invention envisages a suspension system and in particular an active pneumatic vehicle suspension system which enhances the ride quality and comfort user and/or that effectively isolates the precision instruments, thereby improving accuracy of the precision instruments, The presently disclosed invention overcomes one or more drawbacks associated with the conventional pneumatic suspension systems.
More specifically, the inventors of the present invention have come up with an active pneumatic suspension system that does not need any 8 of 16 damper and/or force actuators to reduce and/or eliminate the vibrations being transmitted to a first support member (which may be coupled to a vehicle body or a table supporting precision calibration instruments. 2017100911 03 Μ 2017
The presently disclosed invention addresses the drawbacks associated with the conventional active pneumatic suspension systems by providing an active pneumatic suspension system that essentially does not need any damper and/or force actuators and comprises a suspension assembly comprising a pneumatic suspension unit that is in fluid communication with a compressed air source via a control valve. The control valve is communicatively connected with an electronic circuit that controls the opening of the control valve based on the displacement signals received from first and second displacement sensors disposed on a first support member and a second support member of the vehicle and/or the support of the precision instrument, the first and second displacement sensors being configured to detect displacements of the first support member and the second support member.
More specifically, the displacement signals are converted to displacement velocities of the first support member and the second support member and the difference in the velocities of the first support member and the second support member is used to control the control valve, which in turn controls the pressure inside the pneumatic 9 of 16 suspension unit thereby controlling the stiffness of the pneumatic suspension unit, which in turn provides a smooth ride and comfort the user and/or that effectively isolates the precision instruments, thereby improving accuracy of the precision instruments. 2017100911 03 Μ 2017
The presently disclosed invention is described herein below with reference to the accompanying drawing.
Figure 1 illustrates a block diagram of an active pneumatic suspension system in accordance with an embodiment of the presently disclosed invention.
More specifically, referring the figure 1, wherein a block diagram for an active pneumatic suspension system (100), in accordance with the present invention, is depicted. The active pneumatic suspension system comprises a pneumatic suspension assembly (102) having a first operative end (102a) and a second operative end (102b) and comprising a pneumatic suspension unit 104. The pneumatic suspension assembly (102) is suitably secured to a first support member (106) at said first operative end (102a); and a second support member (108) at said second operative end (102b).
Typically, the pneumatic suspension assembly (102) can be secured to the first support member (106) at the first operative end (102a) and the second support member (108) at the second operative end (102b) 10 of 16 using fastening means such as screws, bolts, fasteners etc. 2017100911 03 Μ 2017
The pneumatic suspension assembly (102) further comprises a first displacement sensor (110a), suitably disposed on said first support member (106), for detecting displacement in a vertical direction of said support member (106) and generating a first displacement signal and a second displacement sensor (110b), suitably disposed on said second support member (108), for detecting relative displacement in vertical direction of said second support member (108) and generating a second displacement signal.
The first and second displacement sensors (110a, 110b) are disposed on the first support member (106) and the second support member (108) such that the displacements of the first support member (106) and the second support member (108) can be measured. A signal is generated by each of the first and second displacement sensors (110a, 110b). This is referred to as the first and second displacement signal corresponding to the first and second displacement sensors (110a, 110b), respectively.
Typically, the first and second displacement sensors (110a, 110b) are displacement transducers. For example, the first and second displacement sensors/transducers can be at least one sensor independently selected from the group consisting of Linear variable 11 of 16 differential transformers (LVDT) and accelerometers. 2017100911 03 Μ 2017
Since, the first and second displacement signals generated by the first and second displacement sensors (110a, 110b) are analog in nature; an analog to digital converter (112) is required to convert the signals to digital ones. Hence, an analog to digital converter (112) is provided, wherein the analog to digital converter (112) cooperates with each of said first and second displacement sensors (110a, 110b) and is configured to receive said first and second displacement signals and convert said first and second displacement signals to first and second digitized displacement signals.
Further, a memory (114) is provided for receiving and storing said first and second digitized displacement signals received from said analog to digital converter (112). Typically, the memory can be volatile and/or non-volatile memory or a combination thereof. The memory is in data communication with the displacement sensors to receive and store the signal received therefrom. A processor (116) is communicatively coupled with said memory (114) to receive said first and second digitized displacement signals stored in said memory (114), wherein said processor (116) is configured to compute a difference between said first and second digitized displacement signals to obtain a difference digitized displacement 12 of 16 signal; and a first differential of said difference digitized displacement signal with respect to time to obtain a velocity signal corresponding to each value of said digitized displacement signal value and further reverse the phase of said velocity signal to obtain a phase reversed velocity signal. 2017100911 03 Μ 2017
In order to supply compressed air or any other gas to the pneumatic suspension unit (104), the pneumatic suspension assembly comprises a compressed air source (118) for charging and discharging air under pressure via a control valve (120) to and from said pneumatic suspension unit (104). Typically, the compressed air source (118) is in fluid communication with and connected to the pneumatic suspension unit (104) using pipes and connectors. The connections are not shown in the figure. The compressed air source can be a compressed air tank or can be a compressor that is capable of supplying pressurized air into the pneumatic suspension unit (104). Typically, the pneumatic suspension unit (104) is a bellow type suspension unit. The compressed air from the pneumatic suspension unit (104) maintains a predetermined pressure inside the pneumatic suspension unit (104) and hence maintains a predetermined stiffness therein.
In order to control the pressure and hence the stiffness inside the pneumatic suspension unit (104), the charging and discharging of air to and from the compressed air source (118) is controlled by introducing 13 of 16 the control valve (120) in between the pneumatic suspension unit (104) and the compressed air source (118), wherein the control valve (120) is controlled by a controller (122) that is communicatively coupled with said processor (116). The controller (122) is configured to generate a valve control signal responsive to said phase reversed velocity signal received from said processor (116), which determines the quantum of opening of the control valve (120), which in turn controls the mass flow rate of the air being charged or discharged to and from the pneumatic suspension unit (104). 2017100911 03 Μ 2017
Typically, the pressure of the compressed air provided by the compressed air source (118) is greater than that in the pneumatic suspension unit (104). This facilitates the charging of the compressed air into the suspension unit (104).
In one embodiment the compressed air from the pneumatic suspension unit (104) that is being discharged, can be directed into the compressed air source (118) or can be released into the atmosphere. In case the air is re-introduced into the compressed air source (118), the system is further provided with a compressing means to pressurize the air and introduce it into the compressed air source (118) which may be a tank.
In accordance with the presently disclosed invention, the control valve 14 of 16 (120) is responsive to said valve control signal for controlling charging and discharging of air to and from said pneumatic suspension unit (104), thereby facilitating control of pressure inside said pneumatic suspension unit (104) to a predetermined value, which in turn alters the stiffness value of said pneumatic suspension unit (104). 2017100911 03 Μ 2017
Figure 2 is a graph that compares the response (A) of a conventional pneumatic suspension system that is passive with the response (B) of an active pneumatic suspension system of the presently disclosed invention. It is evident from the graph (responses A and B) that the presently disclosed active pneumatic suspension system provides reduced and/or significantly lower transmissibility or vibrations even at resonance, wherein the active pneumatic suspension system utilizes velocity feedback, wherein the mass flow rate of the air from and into the pneumatic suspension unit (104) is a function of velocity difference between the first support member (106) and the second support member (108).
Thus, the presently disclosed invention overcomes the drawbacks of the conventional pneumatic suspension systems.
ADVANCES AND ECONOMICAL SIGNIFICANCE OF THE PRESENTLY DISCLOSED INVENTION
The presently disclosed invention, as described herein above, provides 15 of 16 several advances including, but that are not limited to, the realization of an active pneumatic suspension system that: 2017100911 03 Μ 2017 - provides enhanced the ride quality and comfort to the user; - effectively isolates the precision instruments, thereby improving accuracy of the precision instruments; and - is simple and economic. 16 of 16
Claims (5)
- We Claim:1. An active pneumatic suspension system (100) comprising: a pneumatic suspension assembly (102) having a first operative end (102a) and a second operative end (102b) and comprising a pneumatic suspension unit 104; said pneumatic suspension assembly (102) being suitably secured to: a first support member (106) at said first operative end (102a); and a second support member (108) at said second operative end (102b); a first displacement sensor (110a), suitably disposed on said first support member, for detecting displacement in a vertical direction of said first support member (106) and generating a first displacement signal; a second displacement sensor (110b), suitably disposed on said second support member, for detecting relative displacement in vertical direction of said second support member (108) and generating a second displacement signal; an analog to digital converter (112) cooperating with each of said first and second displacement sensors (110a, 110b) and configured to receive said first and second displacement signals and convert said first and second displacement signals to first and second digitized displacement signals; a memory (114) for receiving and storing said first and second digitized displacement signals from said analog to digital converter (112); a processor (116) communicatively coupled with said memory (114) to receive said first and second digitized displacement signals stored in said memory (114), wherein said processor (116) is configured to compute: a difference between said first and second digitized displacement signals to obtain a difference digitized displacement signal; and a first differential of said difference digitized displacement signal with respect to time to obtain a velocity signal corresponding to each value of said digitized displacement signal value and further reverse the phase of said velocity signal to obtain a phase reversed velocity signal; a compressed air source (118) for charging and discharging air under pressure via a control valve (120) into and from said pneumatic suspension unit (104); and a controller (122) communicatively coupled with said processor (116) and configured to generate a valve control signal responsive to said phase reversed velocity signal received from said processor (116); wherein said control valve (120) is responsive to said valve control signal for controlling charging and discharging of air into and from said pneumatic suspension unit (104), thereby facilitating control of pressure inside said pneumatic suspension unit (104) to a predetermined value, which in turn alters the stiffness value of said pneumatic suspension unit (104).
- 2. The active pneumatic suspension system as claimed in claim 1, wherein said suspension unit (104) is a bellow type suspension unit.
- 3. The active pneumatic suspension system as claimed in claim 1, wherein said compressed air source (118) is at least one selected from the group consisting of an air compressor, and a compressed air tank.
- 4. The active pneumatic suspension system as claimed in claim 1, wherein the phase of said velocity signal is reversed by 180°.
- 5. The active pneumatic suspension system as claimed in claim 1, wherein said first and second displacement sensors (110a, 110b) are at least one sensor independently selected from the group consisting of Linear variable differential transformers (LVDT) and accelerometers.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IN201721017426 | 2017-05-18 | ||
| IN201721017426 | 2017-05-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU2017100911A4 true AU2017100911A4 (en) | 2017-08-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2017100911A Ceased AU2017100911A4 (en) | 2017-05-18 | 2017-07-03 | An active pneumatic suspension of a vehicle |
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| Country | Link |
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| AU (1) | AU2017100911A4 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115817200A (en) * | 2022-12-02 | 2023-03-21 | 郑州大学 | Method and system for controlling locked rotor of permanent magnet synchronous motor for new energy automobile |
-
2017
- 2017-07-03 AU AU2017100911A patent/AU2017100911A4/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115817200A (en) * | 2022-12-02 | 2023-03-21 | 郑州大学 | Method and system for controlling locked rotor of permanent magnet synchronous motor for new energy automobile |
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| Date | Code | Title | Description |
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| FGI | Letters patent sealed or granted (innovation patent) | ||
| MK22 | Patent ceased section 143a(d), or expired - non payment of renewal fee or expiry |