WO2007099057A2

WO2007099057A2 - Method and device for the monitoring, diagnosis or adjustment of an actuator for actuating a fitting

Info

Publication number: WO2007099057A2
Application number: PCT/EP2007/051727
Authority: WO
Inventors: Thomas Weber
Original assignee: Auma Riester Gmbh+Co. Kg
Priority date: 2006-02-28
Filing date: 2007-02-22
Publication date: 2007-09-07
Also published as: WO2007099057A3

Abstract

The invention relates to a method for the monitoring or diagnosis of at least one component of an actuator (1) for actuating a fitting (8) in the field of process engineering, whereby at least one current actual value of the acceleration of an accelerated mass in at least one defined spatial axis (x, y, z) is recorded, the determined actual value is compared with a pre-defined nominal value, and in the event of a deviation between the actual value and the nominal value outside a pre-determined tolerance range, a message relating to a defective functioning of a system and/or process variable is generated.

Description

description

Method and device for monitoring, diagnosis or adjustment of an actuator for actuating a valve

The invention relates to a method for monitoring, diagnosis or adjustment of an actuator or of at least one component of an actuator for actuating a valve in process or process engineering.

The actuator for actuating a valve is usually composed of an actuator with possibly an electrical control and the valve. The valve is, for example, a valve, a slide, a throttle or a flap. Depending on the valve corresponds to the performed by the actuator adjustment of a rotary, sliding or pivoting movement. In addition, the actuator may be an uncontrolled actuator, an actuator with integrated control, an actuator with an attached controller, or an actuator with a separate controller.

In process and process actuators for valves are designed to the effect that they can transmit high torques (30-500,000 Nm) at low speeds (4 - 180 U / min), the transmitted torque even at low angles of rotation must have high constancy.

Electric actuators for controlling and / or regulating valves are no longer indispensable in process automation. In known actuators, the torque transmission between an electric motor and the valve via a reduction gear, which is designed very differently depending on the application. The reduction gear is necessary to convert the high speed of the electric motor into the desired output speed for operating the valve. As a reduction gear different gear can be used. Examples include a bevel gear or spur gear, a worm gear, a superposition gear or a lever mechanism called. Actuators are offered and distributed by the applicant, which are tailored to a wide variety of requirements. The torque range of rotary actuators reaches up to a torque of 32,000 Nm; With rotary actuators, torques of up to 500,000 Nm can be achieved.

In the following, the design principle of a known example

Stellantriebs described: To reduce the speed of the electric motor in the Output speed, with which the valve is actuated, is used in conjunction with a planetary gear worm gear with worm shaft, worm and meshing worm wheel. To ensure that the worm gear remains at the standstill of the electric motor in the desired rest position, the worm gear has a self-locking. Worm shaft and output hollow shaft with worm wheel usually run in ball or dry plain bearings. The gear compartment is filled with lubricant, so that a maintenance-free operation of the transmission over a longer period is ensured.

The worm shaft is slidably disposed between two Meßfederpaketen on the worm shaft, so that the worm undergoes a translational movement relative to the worm shaft at a torque to be transmitted. This shift, which is a measure of the transmitted torque, is passed to a controller.

Depending on the design of the valve, the actuator must be turned off in the end positions away or torque-dependent. For this purpose, usually two independent measuring systems, namely a displacement and a torque detection are provided in the actuator, which measure the traversed travel or applied to the output shaft torque. The achievement of a desired position or torque is signaled to the controller, which in turn turns off the electric motor.

In order to meet a given in the process automation safety standard, the actuator must be able to be operated in an emergency via a separately operable thumbwheel. This setting wheel is also used, for example, when commissioning the actuator. The thumbwheel is typically a handwheel that is manually operated by the operator, bringing the fitting to a desired position.

For the purpose of separation of manual operation and engine operation, a clutch mechanism is provided. The clutch mechanism is usually designed and / or arranged so that in the engine operation, the rotor directly coupled to the output shaft and the thumbwheel is disengaged, while coupled in manual mode, the output shaft with the thumbwheel and the rotor is disengaged. As a result, a separation between engine operation and manual operation is possible. In particular, the clutch mechanism is designed such that the setting wheel is automatically disengaged from the rotor shaft as soon as the actuator operates in engine operation - the engine operation thus takes precedence over the manual operation. Corresponding actuators are offered and distributed by the applicant.

In addition, from DE 10 2004 048 366 Al a direct drive has become known, in which the reduction gear can be dispensed with entirely. Here, the stator and the rotor of the electric motor are directly - ie without interposed reduction gear - assigned in predetermined areas of the output shaft, which is connected to the valve.

Actuators are exposed during their intended use of a variety of interference. In particular, mechanical interference causes the actuator or individual components of the actuator are set in vibration and vibrations occur. As a result, the actuator can be limited in its function. Experience has shown that vibrations in the range of 90-180 Hz are particularly dangerous, since resonance effects can occur here. In the worst case, such disturbances lead to destruction of the actuator or a component of the actuator. The vibrations are triggered by vibrations in the closer or wider environment of the actuator. As an example, the disturbing influence of a pump is mentioned, which is installed in the same way as the actuator in the process plant.

Vibrations on the actuator - and in particular on the valve - can continue to be triggered by the occurrence of so-called. Cavitations. Cavitation is the formation and dissolution of cavities in liquids, which are caused by pressure differences, mainly due to cross-sectional changes in the valve. The effect can be explained with the help of Bernoulli's law, according to which the pressure in a liquid is lower the higher its velocity. As the velocity of the liquid becomes so high that the static pressure falls below the vaporization pressure of the liquid, vapor or gas bubbles form in the liquid. As the static pressure increases, the vapor in the cavities suddenly condenses. This is accompanied by extreme pressure peaks, these components of the actuator arranged in the environment or the actuator itself causing them to vibrate mechanically. Parts of the fitting can erode the surface, which sooner or later leads to malfunction or failure of the affected component.

The invention is based, to detect the occurrence of a malfunction on an actuator or on a component of the actuator early on the object.

The object is achieved in that the actual value of the acceleration or the Acceleration force of an accelerated mass in a spatial axis or in several spatial axes is detected, that the actual value is compared with a predetermined setpoint, and that in the case of lying outside a predetermined tolerance range deviation between the actual value and the setpoint a message about a malfunction of the actuator or affected component of the actuator (system size) or another process variable is generated.

As a typical malfunction is a vibration vibration in the environment of the

To call actuator or in the actuator. Such a vibration can be caused, for example, by a pump which performs a periodic pumping movement. Experience has shown that actuators in the range of 90-180 Hz are very sensitive to vibrations in their environment, since the control system is subject to very high mechanical loads.

A typical process-related malfunction is caused by

Cavitations, as u.U. occur in fittings. Cavitations also lead to vibrations of the actuator, and here the valve. In addition, they cause erosion of the affected component within a very short time.

Furthermore, the invention relates to a method for monitoring or diagnosis of an actuator in process and process technology, wherein in a predetermined time interval successively in predetermined time steps, the actual values of the acceleration of an accelerated mass in at least one spatial axis are detected and wherein a warning message is generated if the actual values of the acceleration change within the predetermined time interval such that they lie outside a predetermined tolerance range. On the basis of these method steps, the occurrence and possibly the changing occurrence of vibrations on the actuator or on individual components of the actuator can be detected over an extended period of time; then conclusions can be drawn on the cause of the unwanted vibrations.

In addition, the invention relates to a method for determining the

Installation position of at least one component of an actuator, wherein the acceleration of the component of the actuator is determined in at least one spatial axis and wherein the component of the actuator is oriented so that it undergoes a predetermined acceleration in a given spatial axis. If the installation position is correct, specified by the manufacturer, the life of the actuator is at its maximum. If the installation position is changed or the installation position changes over time, this usually goes hand in hand with a reduced lifetime of the actuator.

In the correct installation position of the actuator, for example, there is always enough lubricant in the gearbox, and the actuator can e.g. 15 million operations. However, if the actuator is installed overhead, the lubrication of the transmission is limited and the number of possible switching cycles or the life of the actuator is sometimes reduced. An alternative solution is to indicate to the operator, instead of the shortened lifetime, a shortened time interval between two maintenance intervals.

An advantageous development of the aforementioned invention proposes that at least one component of the actuator is aligned so that it experiences the acceleration of gravity in the one spatial axis, while the accelerations in the two perpendicular spatial axes are substantially zero.

Advantageous developments of the aforementioned variants of the invention provide that the information - ie the warning message and the existing resonance frequency of the vibration - the operator visual and / or audible is displayed. Alternatively, the information is forwarded to a control room. It is further provided that the information is stored as a function of time. Since the control room also has other information from the process and from the system 'actuator' available, it is possible, for example, to detect whether the vibrations caused by the temporary operation of a pump or by the opening and closing of a slide. If the correlations are known, suitable countermeasures can be taken which subsequently largely suppress or exclude the vibrations. By detecting vibrations in the process that affect the actuator, and taking appropriate countermeasures or precautionary measures, the function and life of the actuator or affected component can be increased.

It is considered particularly advantageous in connection with the variants of the invention described above, when the acceleration is measured by means of an acceleration sensor or by means of a plurality of acceleration sensors. The force or acceleration sensors are mounted in or on the actuator. They capture the acceleration or the acting force in one or more spatial axes.

It is preferably provided that it is the acceleration sensor is an acceleration sensor, the simultaneous information about the accelerations in the three mutually perpendicular spatial axes supplies. This makes it possible to localize from which spatial direction the excitation essentially takes place. In particular, the acceleration sensor is a substantially planar vibration resonator, as has become known, for example, from EP 1 062 480 B1. Of course, it is also possible to use an acceleration sensor, which is an integrated gyroscope made of semiconductor material, as has become known, for example, from EP 1 365 211 A1. It goes without saying that the variants of the invention work in principle with any acceleration sensor.

The sensitive in at least one spatial axis acceleration sensor is attached to the actuator consisting of actuator and valve. It can also be mounted in the immediate vicinity of the actuator. The actuator may be an uncontrolled actuator, an integrated control actuator, an actuator with an attached controller, or an actuator with a separate, remote controller. Preferably, the at least one acceleration sensor is arranged in an additional module, wherein the additional module in or on the actuator, consisting of actuator and valve, or on a component of the actuator is also subsequently fastened.

The invention will be explained in more detail with reference to the following figures. It shows:

1 is a schematic representation of an actuator or an actuator in side view,

1a is a schematic representation of an electronic circuit board of an actuator with vibration sensor,

2a shows a schematic representation of a first embodiment of the actuator according to the invention,

2b shows a schematic representation of a second embodiment of the actuator according to the invention,

[0030]

2c shows a schematic representation of a third embodiment of the actuator according to the invention,

Fig. 2d is a schematic representation of a fourth embodiment of the actuator according to the invention and

3 shows a graphic representation of the amplitudes of three vibration sensors positioned at different regions in the actuator as a function of a constant amplitude over a predetermined frequency range. Fig. 1 shows a schematic representation of an actuator 9 in side view. Corresponding actuators 9 are offered and distributed by the applicant in a variety of different, tailored to the particular application embodiments. Known actuators 9 lead, for example, the name AUMA SA. The actuator 1 shown in Fig. 1 is composed of an electric actuator 2 and an electrical control 3. In case of failure of the controller 3, the actuator 2 via the thumb wheel 6 can be operated. The valve 8 can be coupled via the output shaft 7 to the actuator 2. The usual operation of an actuator 2 is already set forth in the introductory part of the description, so that at this point an additional description of an actuator 2 is dispensed with.

In Fig. Ia, an electronic board 4, e.g. in the actuator 2 of an actuator

I can be incorporated, outlined. In addition to a microprocessor 13 and a memory unit 5, a semiconductor or vibration sensor 11 (MEMS = Micro Electrical Mechanical System) is arranged on the electronic board 4. The acceleration sensor 11 is a substantially planar vibration resonator, as has become known, for example, from EP 1 062 480 B1. Of course, it is also possible to use an acceleration sensor, which is an integrated gyroscope made of semiconductor material, as described, for example, in EP 1 365 211 A1. In connection with the invention, however, all known configurations of sensors for acceleration measurement can be used.

Fig. 2a shows a schematic representation of a first embodiment of the actuator 1 according to the invention. The actuator 1 consists of the valve 8 and the actuator 2. In this embodiment, acceleration sensors 11 may be positioned on the following components, where quite an acceleration sensor

I 1 - depending on the application - may be sufficient for the detection of disturbing vibrations:

- on the actuator 2 or in the immediate vicinity of the actuator 2 - marking A

- in the fitting 8 - marking B

- on the fitting 8 - marking C

- in actuator 2 - marking D

- on the actuator 2 - marking E

Fig. 2b shows a schematic representation of a second embodiment of the actuator 1 according to the invention. Here, the actuator 1 consists of the valve 8 and The actuator 2 with integrated control 3. Acceleration sensors 11 can be mounted here in the following places:

- on the actuator 1 or in the immediate vicinity of the actuator 2 - marking A

- in the fitting 8 - marking B

- on the fitting 8 - marking C

- in actuator 2 with integrated control 3 - marking D

- on the actuator 2 with integrated control 3 - marking E In Fig. 2c is a schematic representation of a third embodiment of the actuator 1 according to the invention can be seen. Here, the actuator 1 consists of the valve 8, an actuator 2 and an attached controller 3. One or more acceleration sensors 11 may be provided at different positions:

- on the actuator 1 or in the immediate vicinity of the actuator 1 - marking A

- in the fitting 8 - marking B

- on the fitting 8 - marking C

- in actuator 2 - marking D

- on the actuator 2 - marking E

- in the control 3 - marking F

- on the control 3 - marking G [0039]

Fig. 2d shows a schematic representation of a fourth embodiment of the actuator 1 according to the invention. In this figure, an actuator 1, consisting of the valve 8, the actuator 2 and the remote control 3 can be seen. The controller 3 may be mounted in the vicinity of the actuator 1 or in the control room 10. In order to be able to detect undesired vibrations that occur in the process or in the actuator 1 at an early stage and to draw conclusions about defined malfunctions in the process or in the actuator and to remedy this, at least one acceleration sensor is provided at one of the following positions:

- on the actuator 1 or in the immediate vicinity of the actuator 1 - marking A

- in the fitting 8 - marking B

- on the fitting 8 - marking C

- in actuator 2 - marking D - on the actuator 2 - marking E

The attachment of acceleration sensors 11 at different positions is therefore useful because the load tolerances of the individual components may well be different. Usually, the controller 3 is the component that is the most sensitive to vibrations, especially in the arrangement of FIG. 2c, since there by resonance small vibrations on the actuator 1 lead to very large elevations in the controller 3.

Furthermore, by comparing the measured values of acceleration sensors which are attached to the actuator 1 at different positions, conclusions can be drawn as to which system or process variable the parasitic oscillation is excited - ie where the cause of the interference is. Helpful in this context is the acquisition of measured values in the three spatial directions x, y, z.

In Fig. 3, the frequency-dependent amplitude characteristic is shown in a structure of the actuator 1 of FIG. 2c. In this structure, the acceleration sensors I Ia (MEMS), I Ib (sensor 1) are fixed at the position marked D and a third sensor 11c (sensor 2) at the position with the label G. In the structure of the actuator 9 was a constant amplitude at the interface: Armature 8 to actuator 2 in the direction of the x-axis excited to vibrate.

Both vibration sensors I Ia and I Ib react almost identically to the excitation by the constant source of interference, as the response curves of the two vibration sensors 1 Ia, 1 Ib show. Out of the frame falls the vibration sensor 1 Ic (sensor 3) attached to the controller 3. As can be seen from the graphs, the disturbance in the region of the fitting 8 leads to a very heavy load on the control 3. In the case of resonance, almost 12 g act on the components of the control 3 here. It goes without saying that the life of the components of the controller 3 is considerably reduced under the influence of such loads. In order to avoid a malfunction of the controller 3 or even their destruction, a warning message is generated according to the invention, which informs the operator of the fault. To analyze the possible cause of the fault, the frequency at which the overshoot occurs can be displayed or read out.

Appropriate installation or mounting positions can be determined by appropriate preliminary tests in order to be able to select suitable and cost-effective acceleration sensors 11. According to the test findings, the setpoints be determined.

The warning message is displayed on site, e.g. on a display, e.g. in the controller 3 is displayed. Alternatively, the warning message can be forwarded with the determined measured values from one or more vibration sensors 11 to a higher-level control room 10. The corresponding communication is e.g. via one of the known fieldbus (e.g., Profibus). Since the control room 10 also has information about other components of the system, for example about the operation of a pump, can be due to temporal correlations locate the cause of the disorder. Based on the knowledge of how often a component of the actuator 1 is exposed to different loads, a statement about the life of the actuator 1 can be made. The operating personnel are preferably informed in good time prior to the failure of the monitored component that replacement of a defined component of the actuator 1 must take place shortly. This effectively prevents an uncontrolled shutdown of the process plant with possibly extended waiting times for the supply of spare parts.

By the use of one or more acceleration sensors 11, the correct installation position of one or more components of the actuator 1 - ie the valve 8, the actuator 2 and the controller 3 - determine. If the installation is not carried out according to the specifications of the manufacturer, a message is generated that the measured deviation from the correct installation position is accompanied by a correspondingly defined shortening of the maintenance intervals or the service life of the actuator 1 or a single component of the actuator 1. The operating personnel then have the option of changing the installation position or optimally adapting the maintenance intervals of the actuator 1 or its individual components to the selected installation position.

[0048] List of Reference Numerals

[0049] 1 actuator

2 actuator

3 control

[0052] 4 control board

5 storage unit

6 setting wheel

7 output shaft

8 fitting

9 actuator 10 control room

[0059] 11 acceleration sensor

12 additional module

13 microprocessor

A vibration sensor

B vibration sensor

C vibration sensor

D vibration sensor

E vibration sensor

[0067] F vibration sensor

[0068] G vibration sensor

Claims

claims

1. A method for monitoring or diagnosis of at least one component of an actuator (1) for actuating a valve (8) in process or process engineering, wherein at least one current actual value of the acceleration of an accelerated mass in at least one defined spatial axis (x , Y, z) is detected, wherein the determined actual value is compared with a predetermined desired value, and wherein in the case of a lying outside a predetermined tolerance range deviation between the actual value and the setpoint, a message about a malfunction of a system and / or process variable is generated ,

2. A method for monitoring or diagnosis of at least one component of an actuator (1) for actuating a valve (8) in the process or process technology, wherein in a predetermined time interval successively in predetermined time steps, the actual values of the acceleration of an accelerated mass in at least one defined spatial axis (x, y, z) are detected and wherein a message about a change in a process or system size is generated when the actual values of the acceleration within the predetermined time interval change such that they are outside a predetermined tolerance range.

3. Method for determining the installation position of at least one

Component of an actuator (1) for actuating a valve (8) in the process or process technology, wherein the acceleration of the component of the actuator (1) in at least one defined spatial axis (x; y; z) is determined and wherein the component of the actuator (1) is aligned so that it experiences a predetermined acceleration in the defined spatial axis (x; y; z).

4. The method of claim 3, wherein at least one component of the

The actuator (1) is oriented to experience the acceleration of gravity in one space axis (x; y; z) while the accelerations in the two spatial axes (y, z; x, z; are essentially zero.

5. The method according to any one of claims 1-3, wherein the information the

Operating personnel visually and / or acoustically displayed.

6. The method of claim 5, wherein the information to a control room (10) is forwarded.

7. The method according to claim 5, wherein the information is dependent on the

Time is stored in a memory unit (5).

8. The method according to one or more of the preceding claims, wherein the acceleration by means of an acceleration sensor (11) or by means of a plurality of acceleration sensors (I Ia, I Ib, ...) is measured.

9. The method according to one or more of the preceding claims, wherein based on the duration and / or strength of the vibrations on one or more components of the actuator (1) a message regarding the expected life of the actuator (1) or individual Components of the actuator (1) is determined and / or wherein a message with respect to the remaining time until the next maintenance interval of the actuator (1) or a component of the actuator (1) is determined.

10. Apparatus for carrying out the method according to at least one of

Claims 1-9, wherein it is the acceleration sensor (11) in one of the three spatial directions (x, y, z) measuring acceleration sensor.

11. The device according to claim 10, wherein it is in the

Acceleration sensor (11) is a substantially planar vibration resonator.

12. The apparatus of claim 10, wherein it is in the

Acceleration sensor (11) is an integrated, made of semiconductor material gyroscope.

13. The apparatus of claim 10, 11 or 12, wherein the

Acceleration sensor (11) or the acceleration sensors (I Ia, I Ib, ..) is arranged or arranged in an additional module (12), wherein the additional module (12) on the actuator (1), consisting of actuator (2) and fitting (8), or on or in the immediate vicinity of a component of the actuator (1) can be fastened.