STATIONARY VIBRATION ISOLATION SYSTEM AND CONTROL METHOD THEREOF

Abstract

A stationary vibration isolation system including a plurality of isolators by way of which a load which is mounted in a vibration isolated manner is supported. The vibration isolation system includes a plurality of actuators by way of which vibrations of the load are actively countered. Each isolator respectively has its own separate control unit with a digital-analog converter for controlling the actuators.

Claims

1. A stationary vibration isolation system, comprising: a plurality of actuators configured for actively countering vibrations of a load; and a plurality of isolators configured for supporting the load which is mounted in a vibration isolated manner, each of the isolators including a respective control unit coupled with and configured for actuating the plurality of actuators, each of the control units including a respective digital-analog converter coupled with the plurality of actuators.

2. The stationary vibration isolation system according to claim 1, wherein each of the control units further includes a respective processor, each of the processors being coupled with each of the digital-analog converters, each of the processors being configured for generating digital control signals and communicating the digital control signals to each of the digital-analog converters, each of the digital-analog converters being configured for converting the digital control signals into analog control signals for actuating the plurality of actuators.

3. The stationary vibration isolation system according to claim 1, further comprising a central control unit connected to each of the control units, the central control unit is configured for transmitting control signals to each of the control units.

4. The stationary vibration isolation system according to claim 1, wherein each of the control units is configured to actuate the actuators, independently of a central control unit.

5. The stationary vibration isolation system according to claim 1, further comprising a bus system, and wherein the control units of the plurality of isolators are connected with one another in-series with the bus system.

6. The stationary vibration isolation system according to claim 5, wherein the bus system is a real time ethernet capable bus system.

7. The stationary vibration isolation system according to claim 6, wherein each of the control units includes an analog-digital converter configured for processing a sensor signal.

8. The stationary vibration isolation system according to claim 1, wherein the control units of the plurality of isolators are connected with one another via at least one of a bus system, a central control unit, a central configuration, and a diagnostic unit.

9. The stationary vibration isolation system according to claim 1, further including a plurality of sensors coupled with each of the control units, the plurality of sensors being configured for sensing vibrations of the load.

10. The stationary vibration isolation system according to claim 9, wherein at least one of the plurality of actuators and the plurality of sensors are integrated into the plurality of isolators.

11. The stationary vibration isolation system according to claim 1, wherein compensating forces are generated in at least two degrees of freedom via the plurality of actuators.

12. The stationary vibration isolation system according to claim 11, wherein the compensating forces are generated in at least one of three translational degrees of freedom and three rotational degrees of freedom.

13. The stationary vibration isolation system according to claim 1, further comprising a machine mounted in a vibration isolated manner, the machine being configured for processing and measuring at least one of semiconductor components, nanostructured elements of laboratory equipment, and medical devices.

14. The stationary vibration isolation system according to claim 1, wherein a number of isolators of the plurality of isolators is not limited by a central control unit.

15. The stationary vibration isolation system according to claim 1, wherein each of the isolators includes a respective pneumatic spring coupled with the respective control unit, wherein each of the control units is configured for actively controlling each of the pneumatic springs.

16. A method for controlling an active stationary vibration isolation system, comprising: providing a plurality of actuators and a plurality of isolators, each of the isolators including a respective control unit coupled with the plurality of actuators, each of the control units including a respective digital-analog converter coupled with the plurality of actuators; supporting a load, by the plurality of isolators, which is mounted in a vibration isolated manner; and actively countering, by the control units actuating the plurality of actuators, vibrations of the load.

17. The method according to claim 16, wherein each of the control units further includes a respective processor, each of the processors being coupled with each of the digital-analog converters, wherein the step of actively countering vibrations of the load includes generating, by each of the processors, digital control signals and communicating the digital control signals to each of the digital-analog converters, and converting the digital control signals into analog control signals, by each of the digital-analog converters, for actuating the plurality of actuators.

18. The method according to claim 16, further comprising a central control unit connected to each of the control units, the central control unit being configured for transmitting control signals to each of the control units.

19. The method according to claim 16, wherein the control units of the plurality of isolators are configured to actuate the actuators, independently of a central control unit.

20. The method according to claim 16, further including a plurality of sensors operably connected to each of the control units, wherein the method further includes a step of sensing vibrations of the load and providing sensor signals, by the plurality of sensors, to each of the control units.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0065] FIG. 1 shows a schematic view of the basic construction of a stationary vibration isolation system known from the current state of the art;

[0066] FIG. 2 shows a first embodiment of the invention, wherein the control units of the isolators are connected with a central control unit;

[0067] FIG. 3 shows another embodiment, wherein the isolators are connected only with a configuration and/or diagnostic unit;

[0068] FIG. 4 illustrates the illustrates the simple scalability of the inventive vibration isolation systems;

[0069] FIG. 5 also illustrates the simple scalability of the inventive vibration isolation systems in further detail;

[0070] FIG. 6 is a schematic view of an isolator according to the invention; and

[0071] FIG. 7 is a flow chart of the process steps according to one embodiment of the invention.

[0072] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0073] FIG. 1 shows a schematic view of the basic construction of a vibration isolation system 1 known from the current state of the art.

[0074] Vibration isolation system 1 includes a plurality of isolators 2A, 2B, 2C, 2D which comprise a spring and support a load 4 which is mounted in a vibration isolated manner.

[0075] Load 4 which is mounted in a vibration isolated manner can include for example a pad on which a machine for processing of semiconductor components (not illustrated) is mounted in a vibration isolated manner.

[0076] Each one of isolators 2A, 2B, 2C, 2D includes actuators 5A, 5B, 4C, 5D and sensors 6A, 6B, 6C, 6D. Sensors 6A, 6B, 6C, 6D capture vibrations of load 4 which is mounted in a vibration isolated manner and/or of the base of the isolator which is coupled with the floor.

[0077] The sensors are connected with central control unit 3. On the basis of the signals from sensors 6A, 6B, 6C, 6D, control unit 3 calculates compensation signals for control of actuators 5A, 5B, 5C, 5D.

[0078] This results in a star shaped connection of sensor 6A, 6B, 6C, 6D and actuators 5A, 5B, 5C, 5D with control unit 3.

[0079] This involves expensive wiring, in particular because sensors 6A, 6B, 6C, 6D 6A, 6B, 6C, 6D generally deliver an analog signal and because actuators 5A, 5B, 5C, 5D are controlled with an analog signal.

[0080] Thus, the control unit is not only connected via data transmission lines with isolators 2A, 2B, 2C, 2D, but lines have to be provided via which partially higher currents are transmitted for control of actuators 5A, 5B, 5C, 5D.

[0081] In a first embodiment, FIG. 2 shows a vibration isolation system 1 according to the invention. According to the invention, each isolator 2A, 2B, 2C, 2D includes its own control unit 8A, 8B, 8C, 8D.

[0082] Data of sensors 6A, 6B, 6C, 6D is collected via control units 8A, 8B, 8C, 8D, digitized and at least pre-processed.

[0083] In this embodiment, isolators 2A, 2B, 2C, 2D are connected via a bus system 7 with a central control unit 3.

[0084] Central control unit 3 collects the data from isolators 2A, 2B, 2C, 2D and on the basis of the control parameters which were calculated by decentralized control units 8A, 8B, 8C, 8D via sensors 6A, 6B, 6C, 6D and actuators 5A, 5B, 5C, 5D, calculates set values for actuators 5A, 5B, 5C, 5D.

[0085] These set values are transmitted via bus system 7 to control units 8A, 8B, 8C, 8D of the individual isolators 2A, 2B, 2C, 2D.

[0086] By use of bus system 7, wiring costs are reduced. Only a bus cable and a voltage supply are necessary for each isolator 2A, 2B, 2C, 2D.

[0087] In this embodiment the control parameters are set in central control unit 3. The sensor data is transmitted by isolators 2A, 2B, 2C, 2D to central control unit 3. The data is evaluated and the set values for actuators 5A, 5B, 5C, 5D are calculated in central control unit 3.

[0088] Since each isolator 2A, 2B, 2C, 2D has its own control unit 8A, 8B, 8C, 8D it is possible to outsource calculating operations from central control unit 3 and/or to send the sensor data, prefiltered to central control unit 3.

[0089] FIG. 3 shows an alternative embodiment of the invention. According to the embodiment illustrated in FIG. 3 the data of the sensors is processed directly in control units 8A, 8B, 8C, 8D of isolators 2A, 2B, 2C, 2D.

[0090] Each isolator 2A, 2B, 2C, 2D has its own control parameters on the basis of which actuators 5A, 5B, 5C, 5D are controlled. A central control unit as discussed in the embodiment according to FIG. 2 is thus not required.

[0091] In this embodiment, isolators 2A, 2B, 2C, 2D or respectively control units 8A, 8B, 8C, 8D of isolators 2A, 2B, 2C, 2D are connected via a bus system 7 with a configuration and/or diagnostic unit 9.

[0092] Via configuration and/or diagnostic unit 9, data can be exchanged with control units 8A, 8B, 8C, 8D. However, configuration and/or diagnostic unit 9 does not calculate any control values for control of actuators 5A, 5B, 5C, 5D on the basis of the sensor signals but serves only to upload data for configuration and/or error control.

[0093] As illustrated in FIG. 4 the invention provides simple scalability of vibration isolation system 1 in regard to the number of isolators 2A-2N. Isolators 2A-2N are connected in series to a bus system 7. No individual lines originating from central control unit 4 are required for each sensor and actuator. Other than that, the embodiment according to FIG. 4 is consistent with the embodiment according to FIG. 2.

[0094] It relates therefore to the embodiment of the invention in which an additional central control unit 4 is provided in spite of decentralized control units 8A-8N which are assigned to isolators 2A-2N.

[0095] However, because central control unit 4 is connected only to bus system 7, the control unit can be integrated into the active vibration isolation, irrespective of the number of isolators 2A-2N. The number of isolators 2A-2N is therefore limited possibly only by the maximum data transmission rate of bus system 7. Generally, this is high enough that it is not an issue in regard to the number of isolators 2A-2N that is useful in practice.

[0096] As illustrated in FIG. 5 this applies also to a vibration isolation system 1, wherein isolators 2A-2N are not connected with a central control unit, but, as in this embodiment only, with a configuration/diagnostic unit 9.

[0097] FIG. 6 illustrates schematically the structure of an isolator 2, as can be used in particular for the vibration isolation system illustrated in FIG. 2 to FIG. 5. Isolator 2 includes a spring 10 which, which in this embodiment is in the form of a pneumatic spring.

[0098] The spring is effective in horizontal as well as in vertical direction and supports load 4 which is mounted in a vibration isolated manner on isolator 2.

[0099] Isolator 2 moreover includes actuators 5, 5, and 5. In this schematic illustration, translational compensating forces are generated via actuators 5 and 5 and rotational compensating forces are generated via actuator 5. Isolator 2 includes its own control unit 8 via which actuators 5 to 5 are controlled. The control unit 8 processes sensor signals.

[0100] In this embodiment at least one sensor 6 is provided which captures vibrations of load 4 which is mounted in a vibration isolated manner as well as an additional sensor 6 which captures vibrations of the base, that is prolonging vibrations from the floor. The effective direction of sensors 6, 6 is not illustrated in this schematic depiction. It is understood that different sensors are preferably used for different degrees of freedom, according to actuators 5 to 5 for different degrees of freedom.

[0101] On the basis of the signals of sensors 6 and 6 the control unit controls actuators 5 to 5 in order to reduce vibration through generation of counter forces.

[0102] In concrete terms, control unit 8 includes an analog-digital converter 11, via which the analog sensor signal is converted into a digital signal which is transmitted to a processer 12 in the control unit where a program runs. It is understood that analog-digital converter 11 can be arranged at any desired location of isolator 2for example in control unit 8 or also in sensor 6, 6 itself.

[0103] Via processer 12, a digital control signal is generated which is transmitted to a digital-analog converter 13. Via digital-analog converter 13, actuators 5 to 5 which are preferably designed as solenoid actuators are controlled for active vibration isolation in that currents are produced from the digital control signals via which the solenoid actuator generates counter forces. It is understood that digital-analog converter 13 can also be arranged at any desired location of isolator 2.

[0104] In this embodiment, spring 10 is also integrated into the active vibration isolation.

[0105] Via a digital-analog converter 13 an analog control signal is also produced for a valve via which the pressure of spring 10 is regulated.

[0106] Isolator 2 includes bus connection 14 by way of which the isolator is connected to a bus system 7. Via bus system 7, isolator 2 or respectively control unit 8 can communicate with other isolators and/or with a central control unit and/or with a configuration and/or diagnostic unit. Apart from that, isolator 2 only requires a power source (not illustrated).

[0107] FIG. 7 is a schematic flow chart of the basic principle of an exemplary method of the present invention.

[0108] Vibrations are captured by sensors. On the basis of the sensor signal which is processed in a control unit that is integrated into an isolator, the actuators of the isolators are controlled by the integrated control unit. As an option, control signals can be generated via a primary central control unit.

[0109] With the invention the installation costs of an active vibration isolation system could be reduced in a simple manner and at the same time, scalability in regard to the number of isolators could be increased.

[0110] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

COMPONENT IDENTIFICATION LIST

[0111] 1 vibration isolation system [0112] 2, 2A-2N isolator [0113] 3 central control unit [0114] 4 load, mounted in an isolated manner [0115] 5, 5A-5N actuator [0116] 6, 6A -6N sensor [0117] 7 bus system [0118] 8, 8A-8N control unit of an isolator [0119] 9 configuration/diagnostic unit [0120] 10 spring [0121] 11 analog-digital converter [0122] 12 processor [0123] 13 digital-analog converter [0124] 14 bus connection