EP0429835A1 - Method and arrangement to decrease the risk of being caught between automatic doors - Google Patents

Abstract

By means of this method and the arrangement, in the case of an automatic door, especially in the case of lifts with a controlled door drive which moves doors of a cabin door by means of a motor with a reduction gear and a mechanical drive, and moves doors of a shaft door via mechanical coupling elements, protection against being caught, responding up to the last few mm of a door closing movement with constant force levels, is provided. In this case, this is done by a control error dV being continuously compared during the door closing movement with a maximum permissible control error dVmax produced by a nominal value sensor (3.5) and, if this maximum control error is exceeded, the door is stopped with subsequent reversing. The response levels for an external disturbing force (3.9) are kept constant by a calibration trip computer (3.11) determining values for mass compensation (3.12) and values for friction compensation (3.13) during periodic calibration trips and supplying these values as a compensation value Vk to a second comparator (3.2). In consequence, the magnitude of an external disturbing force (3.9) is also known, or can be measured precisely, with a defined gain of the controller (3.8) and a known torque characteristic of the DC motor (2.1), which creates the precondition for safe protection against being caught. <IMAGE>

Description

The present invention relates to a method and a device for reducing the risk of pinching in automatic doors, in particular in elevators with a regulated door drive, which by means of a motor with a countershaft via a mechanical drive, door leaves of a cabin door and via mechanical coupling members, door leaves of a shaft door from a closed position into an open position and vice versa, and which moves the door leaves in any position between the two end positions open and closed in the same direction or reverses. Pinching elevator users between closing elevator doors must be prevented by means of suitable devices due to the relevant regulations. Such devices usually consist of electromechanical closing force limiters, which have a resilient element in the power transmission between the motor and the door, which actuates an electrical contact by deflection when the force is exerted on the door and initiates a reversal of the door via door control.

US Pat. No. 4,563,625 has disclosed a solution in which an impermissible force on the door is detected without electromechanics. By means of a measuring resistor (230, Fig. 4) in the motor circuit, the voltage drop proportional to the motor current is interpreted as a torque value and compared with an adjustable limit value. If it is exceeded, stop and reverse operations are triggered.

A major disadvantage of this solution is that the closing force must never be greater than the value permitted by the regulations. That reduces unnecessarily the acceleration force of the drive and the short-term overload possibility of an electric motor is not used. Furthermore, with a gradual change in the efficiency in the mechanical drive system, an incorrect response of the closing force limitation and thus a door fault is the result.

The present invention is based on the object of providing a method and a device for limiting the closing force without additional, discrete measuring and switching circuits which limit the motor output.

The object is achieved by the invention characterized in the claims.

The advantages achieved by the invention are essentially to be seen in the fact that the response force of the closing force limitation remains constant and that the protection against jamming is guaranteed up to the last mm of the closing movement. Another advantage is that largely existing control equipment is used for the process and that the engine can be better used.

Fig. 1

die Frontansicht einer automatischen Aufzugstüre,

Fig. 2

ein Blockschema,

Fig. 3

ein Regelschema,

Fig. 4

ein Diagramm einer Fahrkurve

Fig. 4a,

ein Blockschema und

Fig. 5

ein Flussdiagramm.

In the drawings, an embodiment of the subject of the invention is shown and show it

Fig. 1

the front view of an automatic elevator door,

Fig. 2

a block diagram,

Fig. 3

a control scheme,

Fig. 4

a diagram of a driving curve

4a,

a block diagram and

Fig. 5

a flowchart.

1 shows an automatic elevator door 1 with a door motor 1.1, a door drive control 1.2, a belt transmission 1.3 and a drive belt 1.4. With door drivers 1.5, door leaves 1.6 are moved, which have door rollers 1.7, guide pieces 1.13 and safety strips 1.11 with control parts 1.12. Furthermore, there are spreadable shaft door drivers 1.10 on the door wings 1.6. A switching cam 1.15 on the upper edge of the right door leaf 1.6 actuates a limit switch open position 1.9 in the open position and a limit switch closed position 1.8 in the closed position.

FIG. 2 is a block diagram in which functional elements and their relationship to one another are shown on a cabin 2. The door drive control 1.2 contains a uP control 2.3 and a switching electronics 2.4. The door motor 1.1 consists of a DC motor 2.1 and a digital speedometer 2.2. The drive elements 1.3, 1.4 and 1.5 shown in FIG. 1 are combined with a mechanical drive 2.5. The shaft door drivers 1.10 act on a shaft door 2.8. The functional elements 2.5, 1.6 and 2.8 still act on a mechanical locking device 2.6 and this on locking contacts 2.7. The limit switches 1.8, 1.9 actuated by the cabin door wings 1.6 via switching cams 1.15 (FIG. 1) are connected to a control logic part, not shown in this figure, in the uP controller 2.3, which forwards the corresponding signals to a machine room 2.13 via a hanging cable 2.12. The door security strips 1.11 and an anteroom monitoring 2.10 react to effects from a periphery 2.11 and are connected to the uP control 2.3 as well as to the machine room 2.13, in which there is an elevator control, not shown in this figure. A power supply 2.9 supplies the entire door drive control 1.2.

Fig. 3 shows the control scheme with the door drive. The bordered area of the UP control 2.3 has all the elements of the door motor control. A setpoint generator 3.5 essentially consists of the stored travel curves 3.20, 3.21 and 3.22 and the travel curve selector 3.18, which is influenced by an elevator control 3.17. A setpoint V _ref leads from the setpoint generator 3.5 to a first comparator 3.1, to which an actual value V _{ist is also} led from the digital tachometer 2.2 via a DA converter 3.15. A subsequent differential value transmitter 3.6 has a first connection to a limit value comparator 3.7 and a second connection to a second comparator 3.2. In the limit value comparator 3.7, which additionally receives the tolerance values from a setpoint generator 3.5 via a second input, appropriate signals are sent to the elevator control system 3.17 if they are exceeded. A learning trip selector 3.19 influenced by the elevator control 3.17 activates a learning trip computer 3.11, which determines values for a mass compensation 3.12 and a friction compensation 3.13. In a fourth comparator 3.4 these values are added and their sum is led to the second comparator 3.2 as a compensation value V _k . The output of the second comparator 3.2 leads to a
Controller 3.8, in which the corresponding manipulated variable value is generated for subsequent switching electronics 2.4. A second input in the switching electronics 2.4 is connected to the elevator control 3.17. The DC motor 2.1 is controlled by the switching electronics 2.4 on the principle of pulse width modulation. The motor force F _mot leads via a third comparator 3.3 to a drive load 3.10, which in response causes the drive counterforce F _A. An external interference force 3.9 acts as a negative force F _w on the third comparator 3.3 in the event of a fault. The connection of the DC motor 2.1 with the digital speedometer 2.2 is mechanical. The digital tachometer 2.2 is electrically connected to the digital filter 3.15 and via 3.1.1 to the learning trip selector 3.19.

FIG. 4 shows a diagram with the closing travel curve 3.22, which corner points a, b, c, d, e and f have. A real setpoint curve 4.1 is generated by rounding filter circuits from the closing travel curve 3.22. A positive tolerance curve 4.3 with a distance + dV _max and a negative tolerance curve 4.2 with a distance - dV _max from the real target value curve are generated from the real setpoint curve 4.1.

FIG. 4a shows this process. A filter 3.22.1 rounds off the corners of the closing travel curve 3.22 to such an extent that this results in the real setpoint 4.1, which is present in this form at the output of the setpoint generator 3.5 as V _ref . The same value is also fed to a divider 3.22.2. This continuously determines, for example, a 5% share of the current real target value 4.1, and the positive tolerance limit value + dV _max is obtained in this way. In a subsequent inverter 3.22.3, the negative tolerance limit value - dV _{max is} formed.

Fig. 5 is a flowchart showing the functions of a door closing trip. The mode of operation of the invention is explained in more detail below with reference to this and FIG.

When the door is open and the drive command for the elevator is present, the elevator control 3.17 sets the travel curve selector 3.18 to the close position. This process takes place contactlessly and with memory addressing. The closing travel curve 3.22 called up in the memory (not shown) is also stored as a number of straight lines with the corner points a, b, c, d, e, and f. These key points are defined on the occasion of the first learning trip and are, for example, 30% for a, 50% for b, 70% for c, 75% for d, 85% for e and 95% for f of the total closing path of the Door.

After the door hold-open time has expired and if there is no obstacle detection, the door control logic 3.14 releases the door travel close. Then V _ref starts according to the real setpoint 4.1. The first comparator 3.1 of 2.2 derived from the digital speedometer and umgwandelte to an analog value in the DAC value 3.15 V _is fed. The difference between the two values is then available as a control error dV.

In the limit value comparator 3.7, the control error dV is checked for its tolerance. In the undisturbed normal case, ie dV <dV _max , the value dV in the second comparator 3.2 is added a compensation value V _k supplied by the fourth comparator 3.4 and the input signal for the controller 3.8 is formed.

The controller 3.8 produces a modulation signal for the switching electronics 2.4, which in turn controls the DC motor 2.1 according to the previously mentioned principle of pulse width modulation.

The motor force F _mot counteracts a reaction force F _A caused by a drive load 3.10, which has negative values when accelerating and positive values when decelerating. The third comparator 3.3 is used to represent the comparison of forces and is not really available. In the normal case, the external interference 3.9 or F _{w is} not effective.

The timing of the real setpoint 4.1 is controlled depending on the path, which is made possible by the digital tachometer 2.2 via integrator 3.16.

The closing process now runs until the door is closed, which is detected with the closed limit switch 1.8. The mechanical and electrical locking and the locking of the closed and locked door with reduced motor power or an optional holding brake (not shown here) then take place at the end of the closing operation. These functions are also controlled by the elevator control 3.17 via door control logic 3.14. In the event of faulty electrical locking, an interference signal "safety circuit open" 3.14.2 is formed and, in the normal case, an acknowledgment signal 3.14.3 is generated, both for the elevator controller 3.17.

However, the subject of the invention relates to the accident, which is now explained below.

An external interference force 3.9 arises when colliding with an obstacle, whereby for the explanatory example it is assumed that the safety strips 1.11 and the vestibule surveillance 2.10 are intentionally or unintentionally ineffective.

The description for this case begins with the limit value comparator 3.7. In the flowchart in FIG. 5, its function is divided into two steps, the limit value being exceeded being determined in a first step 3.7.1 and its polarity being determined in a second step 3.7.2.

A negative value means: The actual value V _ist has fallen below the current real setpoint 4.1 or V _ref by more than - dV _max . A positive value means: The actual value V _ist has exceeded the current value V _ref by more than + dV _max .

The latter can occur, for example, in the event of a belt break, in which case the suddenly outgoing DC motor 2.1 briefly generates such values via digital tachometer 2.2 and digital filter 3.15 until it is regulated. An interference signal 3.14.1 is then formed in the sequence, followed by switching off via elevator control 3.17 or door control logic 3.14. If the closing door is held open or braked by an external interference force 3.9, a negative overshoot occurs, ie dV> - dV _max . In this case, the DC motor is braked electrodynamically and, if necessary, additionally mechanically to a standstill and a reversal, ie an opening movement, is initiated.

In this context, the question still has to be answered as to why - dV _max exceeded the permissible maximum force, for example 150 Newtons becomes. The motor characteristic curve and the control gain factor result in a reproducible control error dV with a certain external interference force 3.9. These two factors make it possible to define the corresponding positive 4.2 and above all negative tolerance curve 4.3.

It is claimed that the response values for stopping and reversing remain constant. This constant maintenance is achieved by adding the current compensation value V _k in the second comparator 3.2. The current compensation value V _k is newly determined for each learning trip. Learning trip and compensation value transfer are carried out as follows:

As mentioned at the beginning, the setpoint generator 3.5 has a learning travel curve 3.20, which is called up if necessary by the elevator control 3.17 by means of the travel curve selector 3.18. At the same time, the learn run selector 3.19 is activated and the learn run is carried out as a closing movement at constant and very low speed. The chronological course of the control error dV registered with the learning trip computer gives the indication of the mass to be accelerated in the acceleration phase and, over the entire course, the information about the friction conditions on the basis of the determined control error dV. A mass compensation value 3.12 is calculated with the former and a friction compensation value 3.13 with the latter. The two compensation values added together in the fourth comparator 3.4 are then fed to the second comparator 3.2 with each normal closing travel.

In this way, slowly changing friction conditions are continuously compensated, and the response value for the closing force limitation is kept constant.

As is generally the case, the very first learning trip is used to record route data, which then defines the corner points, accelerations and speeds for the driving curves 3.21 and 3.22 will. Learning trips can be carried out at any time interval as required. This can be, for example, once in 24 hours or even every time the door is closed without a lift command.

If the efficiency deterioration is excessive or defined, compensation values V _k are no longer generated, but instead a corresponding interference signal is sent to the elevator control system. Correspondingly high motor currents are required for rapid acceleration and thus also for a high achievable door speed, in particular for the opening movement. Due to the existing thermal inertia of an electric or DC motor, it can be loaded for a short time with very high currents, which make up a multiple of the permissible continuous current, without damage. There is only a current limit with the carbon brushes and the collector, which, however, can be dimensioned accordingly if required. It is advantageous to provide a current limitation in the form of an electronic fuse as semiconductor protection in the switching electronics. It is also claimed that the pinch protection remains effective until the end of the closing movement. With the described method and the device, it is possible to have the closing force limitation act up to the last millimeter of the shooting movement. This is particularly effective against pinching and injuring narrow human limbs such as hands and fingers, but also items of clothing. The importance of pinching protection in the last phase of the closing movement should also be emphasized in another aspect. As FIG. 1 shows, automatic elevator doors 1 with safety strips 1.11 are normal. equipped. However, these only fulfill their functions up to a certain distance from each other. If the front edges of the door have approached five to two cm during a closing movement, for example, the detection systems of the security strips have to be made less sensitive or even switched off to prevent self-detection will.

The invention fulfills the requirement for complete protection against pinching up to the last mm. In this closing phase of the closing movement, the door speed is also so low that the dynamic force component is negligibly small and only the static part is effective. On the basis of these facts, it is even indicated that the response values of the closing force limit can be set significantly below the prescribed maximum value without impairing the door operations in order to protect the elevator users even better. The method and device can be used for any type of automatic door and are not limited to the elevator area. For example, entrance doors of hotels, commercial and residential buildings as well as those of railway and road vehicles can be equipped with the described invention.

Claims (7)

Process for reducing the risk of getting caught in automatic doors, in particular in elevators with controlled door drive, which moves from a closed position to an open position and vice versa by means of a motor with a countershaft, linear door leaf of a cabin door and mechanical coupling elements, and which moves the door leaf in any position stop between the two end positions open and closed, move in the same direction or reverse,
characterized,
that the stopping and reversing on the entire path of a closing elevator door is triggered by a control error +/- dV _max generated by an external interference force 3.9 and exceeding a defined tolerance value. Method according to claim 1,
characterized,
that a positive and negative tolerance curve 4.2 and 4.3 based on a real setpoint 4.1 is generated. Method according to claim 1,
characterized,
that the ratio of external interference force to regulating error dV 3.9 constant retaining compensation value V _k produced and this value V _k from during a learning travel determined mass compensation values 3.12 and friction compensation values is composed 3.13. Method according to claim 1,
characterized,
that the closing of an elevator door in the absence of a travel command for this corresponding elevator is carried out as a learning trip delivering current compensation values V _k . Apparatus for carrying out the method according to claim 1 with an automatic door, in particular for elevators, with a controlled door drive, which moves a wing door of a landing door from a closed position to an open position and vice versa by means of a motor with a countershaft via a linear drive. Door leaves of a cabin door and which moves the door leaves stop in any position between the two positions open and closed, move in the same direction or reverse,
characterized,
that an automatic elevator door 1 has a uP control 2.3, switching electronics 2.4, a DC motor 2.1 and a digital speedometer 2.2. Device according to claim 5,
characterized,
that the uP controller 2.3 includes a setpoint generator 2.5, a driving curve selector 3.18, a first comparator 3.1, a differential value transmitter 3.6, a limit value comparator 3.7, a second comparator 3.2, a controller 3.8, a learning trip computer 3.11, a fourth comparator 3.4, a learning trip selector 3.19 Contains digital filter 3.15 and an integrator 3.16. Device according to claims 5 and 6,
characterized by
that the setpoint generator 3.5 contains a filter 3.22.1, a divider 3.22.2 and an inverter 3.22.3.

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