EP2694766B2 - Method for controlling a door drive - Google Patents

Description

The present invention relates to a method of controlling a door operator, wherein the door operator comprises an electric motor for generating a drive force with angle sensor for generating an angle proportional to the rotation angle of the motor angle signal and guided in the opening and closing direction of a door leaf chains or belts for transmitting the driving force has on the door leaf.

Door drives of the type mentioned are used for example in machine doors, department store doors, elevator doors or other automatic doors. An important aspect to be monitored in the control of the door operator is whether the belt for transmitting the driving force of the electric motor to the door leaf is functional or cracked. According to the EP 0 429 835 A1 is a kind of continuous timing belt monitoring known. According to the EP 0 429 835 A1 is continuously monitored whether there is a change in speed or force during the process of the door, which exceeds a threshold above or below. For example, if the current speed exceeds the current reference value for the speed by more than a predetermined speed difference, this is interpreted as a belt break.

It is an object of the present invention to provide an alternative method for controlling a door operator, with the help of which it can be checked whether in the opening or closing direction of a door leaf guided chains or belts for transmitting the driving force of an electric motor to the door leaf are functional or not.

This object is achieved by a method according to claim 1 or by a method according to claim 2.

The error message corresponds to the fact that there is a chain break or a belt break.

The proposed method for controlling a door drive allows the testing of the functionality of a chain or a belt for transmitting the driving force from an electric motor on a door leaf, especially in a final position of the door leaf, where this information is particularly important for safety reasons. The method proposed here is characterized, inter alia, by the fact that this test is carried out with the aid of parameters which are read out anyway for the purpose of controlling the electric motor on the electric motor. Thus, in a first approach, the value of the motor current in the end position is compared with the value of the motor current measured when trying to continue beyond the end position. If the motor current does not increase, this is an indication that no force is transmitted to the door leaf by the electric motor in order to drive against the resistance of a repository. According to claim 2 is cumulatively also an angle signal in the end position compared with an angle signal when attempting to drive out over the final position. In the same way, the change in the angle value can be compared to the time in the end position and beyond, which would be a measure of the speed. If the angular value only changes insignificantly when moving against the end bearing or the change in the angle value drops sharply over time, this would be an indication that the chain or the drive belt is functional and the power of the motor is transmitted to the door leaf.

An advantage of the proposed method is that parameters are measured and evaluated on the engine, which are measured and evaluated anyway. Therefore, no additional components are required for the door drive to perform the test proposed here on the functionality of the chain or the drive belt. As a result, the door drive can be made particularly compact. In addition, a corresponding door drive has a comparatively lower susceptibility to interference. Because of its simple and compact design, the corresponding door drive is not only suitable as a door drive for newly manufactured automatic doors, but also for retrofitting existing doors.

In a preferred embodiment, when the error message is output, the electric motor is switched off. Since the output of the error message corresponds to a break or a crack of the drive chain or the drive belt, the safety inside and outside of the door leaf is best ensured in such an event by a complete stop of the door drive. If the powered door is integrated into a larger system, such as a machine tool or an elevator, the machine tool or elevator may also be stopped due to the error message.

According to claim 2, it has proven to be particularly advantageous if both the first and second values of the motor current and the first and second values of the angle signal are determined and the error message is output, if the second value of the motor current is less than or equal to the first value of the Motor current is or the second value of the angle signal is greater than the first value of the angle signal. By checking via two independent parameters whether in the end position the chain or the belt is still functional and the error message is issued as soon as a break or a break has been detected via one or the other parameters, a higher level of security can be ensured when detecting such Occurrence can be achieved.

The redundancy in determining the functionality of the chain or the belt is preferably further increased by determining the values of the motor current and / or the values of the angle signal in two independent ways in each case. For this example, a second angle sensor can be used on the electric motor or the current of the electric motor can be measured at various locations. Particularly preferably, both the motor current and the angle signal are measured and these two parameters are each determined redundantly in order to ensure a particularly high level of safety.

In a preferred embodiment, the reaching of the end position is determined from the angle signal and confirmed by an increase of the motor current. Depending on the angle encoder used, the door leaf position can be determined directly as an absolute value via the angle signal, or the current door leaf position can be determined by comparison with a reference value that has once been set. In the event that the drive belt or drive chain are fully functional, as previously stated, the motor current would increase when attempting to continue beyond the final position. By combining these two pieces of information, reaching the end position can be determined with a particularly high level of safety. This allows a further simplification of the door drive, since depending on the safety requirements, the security thus achieved can be high enough to dispense with previously customarily designed as a mechanical safety switch limit switch.

Advantageously, as long as the door leaf is in the end position, a corresponding signal "end position reached" output. This signal can be used outside the door drive. For example, if this signal is output on an automatic machine door, it can be used to shut down the machines located behind the door or to run in a safety mode. In the case of, for example, the door of an elevator car, it is possible, inter alia, to prevent the elevator car from approaching when the door is open via the missing signal "end position reached".

In a further preferred embodiment, the travel speed of the door leaf is set faster or slower in response to an external signal. This variant is particularly suitable for the use of the door drive in carrying out the method described here for automatic machine doors. Thus, for example, the movement speed of the door leaf can be set slower, if for example sensors, such as motion detectors, light barriers, light grids or pressure-sensitive foot mats, operating personnel is detected in the vicinity of the machine door, so as not to jeopardize this. If no operator is near the door, it can be moved at the maximum travel speed to avoid delays in the machining process by the machines behind the machine door.

In a comparable manner, depending on an external signal during the process of the door leaf, its speed and / or the forces occurring during the process can be monitored. This variant is not only suitable for machine doors but also for elevator doors, in particular doors of freight elevators. If it is reported via the external signal that, for example, users are in the door area, monitoring the door leaf speed and / or the forces that occur when moving the door leaf can ensure that no one is being traversed by the door leaf being moved, for example by squeezing , Scissors, bumping or pulling is injured.

In a particularly preferred embodiment, it is determined during the whereabouts of the door leaf in the end position, whether a change in the angle signal takes place and in the positive case, the door leaf is moved in the direction of the angle signal change. In this way, the movement of the door leaf can be started by gently bumping in the desired direction. This variant has proven to be particularly advantageous in goods lifts. In particular, when retrofitting existing freight lifts can be avoided in this way that additional switches must be installed on each floor to cause the closing or opening of the respective goods lift door. This significantly reduces the structural and labor costs when retrofitting freight lifts.

Figur 1

eine perspektivische Ansicht eines Türantriebes;

Figur 2

eine Seitenansicht des Türantriebes aus Figur 1 ;

Figur 3

eine schematische Funktionsskizze des Türantriebs aus den Figuren 1 und 2;

Figur 4

eine schematische Skizze einer Endlageposition;

Figuren 5a,b

den Verlauf des Motorstroms mit der Zeit beim Fahren in die Endlageposition und bei funktionsfähigem Antriebsriemen bzw. -kette oder gerissenem Antriebsriemen bzw. -kette;

Figuren 6a-d

den Verlauf des Winkelwertes und der Winkelgeschwindigkeit mit der Zeit beim Fahren in die Endlageposition und bei funktionsfähigem Antriebsriemen bzw. -kette oder gerissenem Antriebsriemen bzw. - kette; und

Figur 7

schematisch den Verlauf einer bevorzugten Ausführungsform des hier vorgeschlagenen Verfahrens zum Steuern eines Türantriebs.

The present invention will be explained in more detail with reference to a preferred embodiment. Show this

FIG. 1

a perspective view of a door drive;

FIG. 2

a side view of the door drive FIG. 1 ;

FIG. 3

a schematic functional sketch of Door drive from the Figures 1 and 2 ;

FIG. 4

a schematic sketch of a final position;

FIGS. 5a, b

the course of the motor current with time when driving in the end position and with functional drive belt or torn drive belt or chain;

FIGS. 6a-d

the course of the angular value and the angular velocity with time when driving in the end position and with functional drive belt or chain or torn drive belt or - chain; and

FIG. 7

schematically the course of a preferred embodiment of the method proposed here for controlling a door drive.

In the Figures 1 and 2 is a door drive 1 in perspective ( FIG. 1 ) and in side view ( FIG. 2 ). As important components, the door drive 1 to an electric motor 2, which is connected via a toothed belt 4 with a door leaf holder 8. The electric motor 2 of the embodiment of a door drive 1 shown here is a brushless electric motor which has Hall sensors for controlling the motor in its interior. These Hall sensors, not shown here, can be used as absolute angle encoder. In addition, the electric motor 2 has a designed as incremental angle encoder angle encoder 3, which is arranged coaxially to the gear 5 in the present example, via which the toothed belt 4 extends and is driven by the electric motor 2. In a variant, the incremental angle encoder 3 may for example also be arranged coaxially with the motor shaft. Alternatively, the angle encoder 3 can also be arranged on the gear 5 ', which is not driven by the electric motor 2.

The electric motor 2 as well as the gears 5, 5 'are attached to a drive bracket 7, via which the door drive can be attached to objects to be closed. To the drive brackets 7 also 6 end bearings are mounted, which in the present representations according to FIGS. 1 and 2 exploded are shown.

In the example shown here, a door leaf is moved over the toothed belt 4, which can be fastened to the door leaf holder 8. The door leaf holder 8 also has stops 9. These stops 9 are mounted relative to the door leaf holder 8 such that they come into abutment in the respective end bearing 6 when the end position is reached. In the example shown here, the door leaf, which may be attached to the door leaf holder 8, occupy two end position positions, one of which corresponds to a position of a fully opened position of the door leaf and the other end position corresponds to a fully closed position of the door leaf.

Since the brushless electric motor 2 on the one hand has Hall sensors, and on the other hand via a incremental angle encoder 3, two independent angle signals can be obtained at the motor 2. The two angle signals differ i.a. by the fact that the two angle encoders have different resolutions. The incremental encoder generally has a much higher resolution than the Hall sensors as absolute angle encoder. Typically, the resolutions of incremental encoders are several hundred steps per revolution, while the resolution of the Hall sensors is a few steps per revolution. The resolution of the angle sensor formed by the Hall sensors can be further increased by the number of Hall sensors. When determining the door position from the respective angle signal, the transmission will usually have to be taken into account with its respective gear ratio. The gearbox corresponds to a constant factor with a gear ratio.

Furthermore, the motor current can be measured at different locations on the electric motor 2. In order to obtain two independent measured values, in the example shown here, the respective current value is determined once at the input of the electric motor and once at the output of the electric motor. Using the two independent current values in conjunction with the two independent angle values, it is very easy to determine in the end position position whether a break in the toothed belt 4 is present or not. Furthermore, the end position can be determined from these signals with very high reliability, so that the door drive in the example, as in the Figures 1 and 2 is shown, does not need to have a limit switch.

It should be noted that as an angle encoder and a third gear can be provided over which the toothed belt 4 runs to measure its speed. In addition, as an angle sensor and sensors can be used, which count visually and / or magnetically, how many teeth of the respective gear are moved past them.

In FIG. 3 is shown schematically the operation of the door drive. By means of the toothed belt 4, the door leaf 10 which is fixed to the door leaf holder 8, in the direction of the arrow between the two end bearings 6 are moved back and forth, wherein the movement is stopped by abutment of the stops 9 to the respective repository 6. As in FIG. 4 is shown, in the end position in the stop 9 collides with the repository 6, in a first reference run the respective angle value φR be set as the reference value, the end position, for example, as Position x = 0 can be defined corresponds. If, for example, the angle values of an incremental angle encoder are used, starting from the reference angle value cpR, the respective current door leaf position x can be determined by counting the increments. Advantageously, it also takes into account the direction of rotation of the angle change, since in the example shown here, the door leaf can be moved in opposite directions. According to the position determination on the angle value φ, the door leaf can now be moved via the toothed belt 4 and the door leaf holder 8 into an end position at x = 0. Is the final position reached in the FIGS. 5a, b, 6a-d is reached at the time t0, according to the method proposed here, it is attempted to continue infinitesimally beyond this end position. Here you can watch, for example, the motor current. This is schematic in the FIGS. 5a, b shown. In FIG. 5a For the sake of simplicity, it is assumed that the door leaf is driven to the end position with a constant motor current. Of course, the door can be moved with any movement patterns of different power distribution. At the moment t0, in which the end position is reached, abuts the stop 9 on the door leaf holder 8 against the end bearing 6. With functioning timing belt 4, this means that in an attempt to go beyond the final position position a little further, the repository 6 acts as a resistance that generates a counterforce that is transmitted to the motor 2 via the functioning toothed belt 4. This has the consequence that the motor current increases. If the motor current, as in FIG. 5b For example, if it were shown to be constant, this would mean that the counterforce normally exerted by the anvil is not transmitted to the engine. This would be a strong indication that the timing belt 4 is broken.

The increase in the motor current I when passing over the end position also confirms the information that was determined with respect to the position from the angle sensor signal that the end position has been reached. Then the engine can be switched off, or switched to idle, which is in FIG. 5a is represented by the decrease of the motor current at times greater than t0.

In addition to the testing of the toothed belt in the end position via the motor current, the functionality of the toothed belt 4 can also be carried out by evaluating the angle sensor signal φ. On the one hand φ can be directly evaluated, as in the FIGS. 6a, b or, for example, a quantity derived from φ such as the angular velocity dφ / dt included in the FIGS. 6c, d is shown. According to the in FIG. 6 a shown movement pattern of the door leaf 8, the angle φ changes continuously with time, until the time t0 the final position is reached. When the timing belt 4 is functioning, the opposing force of the repository 6 is transferred to the engine via the toothed belt so that it can no longer rotate and accordingly there is no change in angle. Therefore, following the reaching of the end position, the angle φ remains constant even when trying to drive beyond.

Would the timing belt be torn, like this in FIG. 6b is shown, the angle would continue to change continuously as the engine continues to run. Similarly, according to FIG. 6c For example, the angle change with time dφ / dt becomes constant until the end position is reached at time t0 and the angle change dφ / dt is reduced to zero. If the timing belt 4 as in FIG. 6d torn, the angle change dφ / dt would still be non-zero.

It should be noted that unlike a constant speed drive to the final position to, any speeds can be set. It should also be noted that in electric motors a certain degree of slippage may be present, so that when moving out beyond the final position even with a functioning timing belt, a slight change of φ can take place. The reduction of the angular velocity dφ / dt would still be clear.

In FIG. 7 the sequence of a preferred embodiment of the proposed method for controlling a door drive in a kind of flowchart is shown. In a comprehensive variant of the method, the door leaf or a door leaf holder is initially moved against a stop when the door drive is put into operation (step 701). This position is determined as a reference angle .phi..sub.R based on an angle sensor signal present in any case in the case of an electric motor, from which all following positions can be determined by enumerating the angle changes .phi.Xi (step 703). By using the angle sensor signals for position determination, it is possible to move selectively into an end position (step 705).

In this end position position, first angle signals cpA1 and cpB1 can now be measured at an angle transmitter A and optionally an angle transmitter B. In addition, in the example shown here, first motor currents IA1 and IB1 are also measured at two different points A and B on the motor. The motor is then controlled in such a way that an attempt is made to drive the door leaf beyond the end position (step 709) and simultaneously again measure a second angle signal φA2, φB2 at two different angle encoders or a further current signal IA2, IB2 at two different locations (Step 711). Subsequently, it is checked in a following step 713 whether the amounts of the angles in the end position cpA1, cpB1 and beyond the end position φA2, φB2 are unequal or whether the corresponding angle changes in the time interval between t0 and t0 + ε approaches zero and if the current signals IA1, IB1 after reaching end position is less than the current signals IA2, IB2 when attempting to go beyond the end position. If it turns out that at least one of these conditions is met, an error message is issued in a following step 715, which means that the toothed belt is torn with high probability. This leads in the example shown here in step 717 to a stop not only of the door drive itself by switching off the electric motor, but possibly also the higher-level system, such as a machine tool or an elevator.

If it turns out that none of the conditions tested in step 713 are satisfied, not only is it ensured that the toothed belt is not cracked with very high safety, but it is also confirmed independently that the final position is actually reached (step 719). This information may be forwarded in step 721 to other units within a door operator superordinate system, for example to the control of a machine tool shielded by a door-driven door, or to an elevator controller.

As long as the door leaf is in an end position, it can be monitored continuously or by sampling whether the angle signal φ changes, even though there is no significant change in the motor current (step 723). This may in particular be the case when the door leaf is slightly pushed out of its end position to open or close the door leaf, i. to remove him from the current final position. In the example shown here for carrying out the proposed method, upon detection of such a change in the angle signal in step 725, this is taken as a start signal in order to control the motor in such a way that the door leaf is moved out of the end position in the desired direction.

Incidentally, it should be noted that in the choice of the movement or speed profile in the process of the door leaf, external signals can be taken into account, which possibly lead to the speed being increased or decreased, for example.

Claims (9)

1. A method of controlling a door drive, wherein the door drive comprises an electric motor for generating a driving force with an angular sensor for generating an angular signal proportional to the angle of rotation of the motor, and a chain or belt guided in a direction of opening and closing a door leaf for transmitting the driving force to the door leaf to check whether the chain or belt is operational, comprising the steps of:

   - causing the door leaf to travel to an end-of-travel position;

   - determining a first value of the motor current;

   characterized by the steps of:

   - attempting to travel beyond the end-of-travel position;

   - determining a second value of the motor current (IA2, IB2);

   - comparing the first value to the second value and outputting an error message if the second value of the motor current (IA2, IB2) is equal to or smaller than the first value of the motor current (IA1, IB1), wherein the error message corresponds to the fact that there has been a chain or belt break.
2. A method of controlling a door drive, wherein the door drive comprises an electric motor for generating a driving force with an angular sensor for generating an angular signal proportional to the angle of rotation of the motor, and a chain or belt guided in a direction of opening and closing a door leaf for transmitting the driving force to the door leaf to check whether the chain or belt is operational, comprising the steps of:

   - causing the door leaf to travel to an end-of-travel position;

   - determining a first value of the motor current and a first value of the angular signal;

   characterized by the steps of:

   - attempting to travel beyond the end-of-travel position;

   - determining a second value of the motor current (IA2, IB2) and a second value of the angular signal (ϕA2, ϕB2);

   - comparing the first value of the motor current (IA1, IB1) to the second value of the motor current (IA2, IB2) and the first value of the angular signal (ϕA1, ϕB1) to the second value of the angular signal (ϕA2, ϕB2) and outputting an error message if the second value of the motor current (IA2, IB2) is equal to or smaller than the first value of the motor current (IA1, IB1), or if the second value of the angular signal (ϕA2, ϕB2) is greater than the first value of the angular signal (ϕA1, ϕB1), wherein the error message corresponds to the fact that there has been a chain or belt break.
3. The method according to claim 1 or 2, characterized in that when the error message is output the electric motor (2) is deenergized.
4. The method according to any one of claims 1 to 3, characterized in that the values of the motor current (IA1, IB1, IA2, IB2) and/or the values of the angular signal (ϕA1, ϕB1, ϕA2, ϕB2) are each determined in two independent fashions.
5. The method according to any one of claims 1 to 4, characterized in that reaching of the end-of-travel position is determined from the angular signal (ϕ) and is confirmed by an increase in the motor current.
6. The method according to claim 5, characterized in that as long as the door leaf (10) is in the end-of-travel position, a signal "end-of-travel position reached" is output.
7. The method according to any one of claims 1 to 6, characterized in that the traveling speed of the door leaf (10) is adjusted to be faster or slower as a function of an external signal.
8. The method according to any one of claims 1 to 7, characterized in that during the travel of the door leaf (10) its speed and/or the forces arising are monitored as a function of an external signal.
9. The method according to any one of claims 1 to 8, characterized in that while the end-of-travel position is maintained it is determined whether or not a change occurs in the angular signal (ϕ) and, in the affirmative, the door leaf (10) is caused to travel in the direction of change in the angular signal.

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