FI88791C - Method and apparatus for controlling elevator car - Google Patents

Description

88791

METHOD AND APPARATUS FOR CONTROLLING THE LIFT CAR

The invention relates to a method according to the preamble of claim 1 for controlling an elevator car in elevator guides and to an apparatus 5 according to the preamble of claim 5 for implementing the control.

In fast and high-quality elevators, driving comfort has become an increasingly important goal. Lateral oscillation, i.e. the horizontal movements of the elevator car, is an important parameter for driving comfort. One of the most significant causes of lateral oscillation 10 is the relatively rapid displacements caused by the unevenness of the guide line when driving along the conductors. The unevenness of the conductor line may be due to the insufficient quality of the conductor rails or their installation, especially in old buildings where elevators are modernized faster but the old conductors 15 are not renewed. Similarly, the living conditions of buildings, and especially the slight shrinkage of new buildings in the first years, cause transitions to the line. Lateral oscillations can also be caused other than by the unevenness of the guide. For example, the swirling of air around a fast-moving car and the movements of 20 passengers inside the car can somewhat rock the car.

Conventionally, the undesired effects of lateral sports of the elevator car on travel comfort have been reduced by building a suspension and / or damping system 25 in the elevator car roller guides, which consists of passive spring and / or loss elements (shock absorbers). The problem with these is that in order to operate properly at low frequencies, they require a relatively long stroke length for both springs and dampers. Since the payload of the elevator is generally not distributed centrally in the car, i.e. the position of the passengers may vary much during travel and especially when passengers enter or leave the elevator, the eccentric positioning of the load contributes significantly to the support forces acting on the roller guides. These support forces cause the balancing position of the coaching system to move away from the planned balancing position. Because certain elevator technical and safety devices, such as automatic doors and grippers, have relatively small travel clearances, only a few millimeters, passive suspension / damping systems are equipped with motion limiters that prevent a 2-3 mm greater horizontal movement.

5 Such a motion limiter also acts as a switch for possible interference to the car through the controller, reducing travel comfort. The relative effect is accentuated when the lift height, speed and elevator car size are large.

10 actively acting solutions have also been proposed for controlling the lateral movement of the elevator car. For example, the applicant's Finnish patent publication EN C 72947 describes an arrangement in which the position of the elevator car controllers is controlled on the basis of a "wiring map" stored in the computer's memory.

U.S. Patent No. 4,754,849 discloses an active control system in which the position of a reference wire or the like in a shaft relative to a car is detected and upon detecting a deviation from a desired value guided by magnetic guides that contact the conductors non-contact by a magnetic field. However, in certain cases - for example in high-speed elevators, when the movement of the elevator car causes a rather strong turbulence in the air mass in the shaft - such a reference cable can start to vibrate, whereby its usefulness as a reference line deteriorates. The characteristics of the reference system according to the publication, such as the natural frequency and the magnitude of the oscillation, also depend a lot on the length of the line.

The object of the present invention is to provide a method and apparatus for controlling an elevator car in elevator guides, which method and apparatus improve the travel comfort of the elevator car. The method according to the invention is characterized by what is stated in the characterizing part of claim 1. The apparatus according to the invention is characterized by what is stated in the characterizing part of claim 5. Other preferred embodiments of the invention are characterized by what is stated in the other claims.

^ 88791

The invention achieves nun. the following advantages: - A direct and stable guide-independent reference line is obtained to control the travel of the car.

- Reference line monitoring is easy to organize.

5 - The invention is well suited for the modernization of old elevators.

- The invention is suitable to complement other control systems. Fluctuations caused by regular motion deviations due to permanent unevenness of the conductors can be corrected, for example, in the Finnish patent publication EN C

10 72947, which is based on the use of a conductor map and other motion deviations are corrected by the measures according to the invention.

The invention will now be described, by way of example, with reference to a preferred embodiment thereof, with reference to the accompanying drawings, in which - Figure 1 shows an elevator in which the invention is applied, and - Figure 2 shows a control arrangement according to the invention.

Fig. 1 schematically shows an elevator car 2 running in the elevator shaft 1. A laser light source 20 3 is placed on the bottom of the shaft, the light beam of which is directed in the direction of the elevator shaft. The elevator car is provided with detectors 9 and 10 for detecting the position of the laser beam, which are fixedly mounted on the upper and lower part of the elevator car or car frame, respectively. A detector 12 is fixedly placed in the elevator shaft, by means of which the mutual position of the beam and the shaft 25 is monitored, whereby accurate information is obtained as to how much the shaft deviates from the vertical direction under the influence of external factors. By means of the beam splitter 5 and the mirror 6, a part of the beam is conducted as a parallel reference line 7 to the other side of the elevator car. A detector 30 11 mounted substantially on one side of the elevator car 2 than the detectors 9 and 10 detects the position of the parallel reference line relative to the car, thereby obtaining additional information about the position of the car. Of course, a parallel reference line can also be provided with its own light source. When the detectors 9, 10 and 11 are fixedly mounted on the elevator car or car frame, they provide accurate information about the horizontal position of the car part 4 88791 or part of the car frame in the elevator shaft. By combining the beam position information from different detectors, the inclination of the car with respect to the vertical, the displacements in the horizontal direction and the possible rotation with respect to the vertical axis can be determined. The body guides and the institutions affecting them are not shown, but they can be implemented by known technology, for example as described in the applicant's Finnish patent publication EN C 72947.

The detectors 9, 10, 11, 12 are provided with a light-sensitive grid-10, for example a simple video camera is suitable for the purpose, in which case the position of the laser beam in the grid indicates a deviation from normal. The passage of the reference line through the detector can be arranged so that the beam is divided in the detector by a beam splitter and part of the light is directed to the light-sensitive raster 15 acting as a sensor as the end continues its journey. Thus, for example, the deviations obtained by means of the detectors 9 and 10 can result in both a lateral displacement of the elevator car 2 and its inclination. In order to detect the rotation, the deviation from the detector 11 and at least one of the deviation values of the detectors 9, 10 20 are required. Detector 12 "fixes" the top end of the reference line. This way the position of the reference line with respect to the gap is known to the system. Top end monitoring is especially important in tall houses that may oscillate in the wind to a large extent. When the house oscillation is known, the necessary corrections in the control unit, which generates instructions for the actuators connected to the body guides.

Figure 2 schematically shows the flow of different signals in the control system according to the invention. Signals DET1, DET2 and DET3 from detectors 9, 10 and 11 are applied to the control unit 8 to deviate from the equilibrium position. The control unit determines the . If a "map" of the deviation of the guide line is stored for control, then the information contained therein may be included in the information CTRL from the elevator control I i 5 βε 79-j or it may be stored in or in connection with the control unit 8. Based on the above, the control unit generates control signals s1, s2, s3, s4 for the actuators connected to the elevator car controllers. In this way, the position of the body 5 is controlled by the feedback adjustment. If necessary, the body position can be adjusted using standard adjustment techniques.

It will be apparent to those skilled in the art that the various embodiments of the invention are not limited to the examples set forth above, but may vary within the scope of the claims set forth below. For example, from the point of view of the control principle, it does not matter whether the light beam travels from the bottom up or from the top down. Likewise, the light beam may be other than the laser beam, as long as its shape is sufficiently well defined. The beam can also be modified, for example by spreading it in one direction, in which case a second reference line is not required to detect the rotation, but the rotation is detected directly from the same line as the displacement and inclination. Instead of image matrix sensors, so-called pie sensors 20 can also be used as detectors, in which case the deviation from the central one is manifested as an emphasis of the signal from one or some sectors of the pie sensor compared to other sectors. Instead of the actuators acting on the controllers according to the example, actuators acting between the car of the elevator car and the car frame 25 can also be applied.

Claims (8)

A method for controlling an elevator basket in an elevator shaft, in which the method of the elevator basket (2) or at least one of the position of the elevator basket belonging to the shaft (1) is sensed in relation to a reference line formed in the shaft (1). obtained position data (DET1, DET2, DET3) about the elevator car (2) or at least part thereof is utilized to form at least a control signal (sl, s2, s3, s4) used to control at least one control excerpt with which the elevator car (2) is moved sideways, characterized in that the reference line in the elevator shaft (1) is achieved by forming at least one optical line (4.7) directed substantially in the longitudinal direction of the elevator shaft (1). Method according to claim 1, characterized in that the optical line (4,7) is formed by means of a light beam, preferably a laser beam. Method according to any of the preceding claims, characterized in that the position of the shaft (1) and an optical line (4,7) formed in the shaft are sensed, and that at least one of the control signals (sl, s2, s3, s4) for control of the control elements is corrected on the basis of the position of the line and the shaft. Method according to any of the preceding claims, characterized in that at least one of the control signals for a control element is formed by means of specially stored information about the deviation of the guide line. Device for controlling a lift basket in a lift shaft (1), in which is formed a reference line directed along the shaft (1), which means comprises at least one control element arranged to move the lift basket (2) sideways and which is controlled by by means of data on the reference line and the elevator basket (2) or at least one belonging to the relative position of the elevator basket (2), characterized in that the device comprises means (3,5,6) with at least one substantially in the longitudinal direction of the elevator shaft (1). directed optical reference line (4.7) is provided in the shaft 9 88791 (1), and at least one detector (9,10,11) which gives a signal (DET1, DET2, DET3), proportional to the lift basket (2) or at least one more the elevator basket (2) belonging to the part and eating at least one position of the optical reference line (4,7) formed in the elevator shaft, and a control unit (8) which, by means of the signal proportional to the position, at least forms a control signal (sl, s2, s3 , s4) and control the control element. Device according to claim 5, characterized in that the optical line is a light beam, preferably a laser beam. Device according to any of claims 5-6, characterized in that a detector (12) is placed in the shaft (12) whereby the position of the shaft (1) and an optical line formed in the shaft (1) is sensed. Device according to any of claims 5-7, characterized in that information about deviations in the guide line is stored in the control unit (8) or accessible to it.