FR2737712A1 - METHOD AND SYSTEM FOR AUTOMATIC ADJUSTMENT OF THE STOP POSITION OF AN ELEVATOR CAB - Google Patents

Abstract

The system comprises a speed measuring device (32, 36, 38) intended to measure the speed of movement of the car before each stop at the different levels, a microprocessor (44) in which all the values of the precisions are stored in memory. stop PA measured at all levels, in both directions of movement of the car, a stop management program (46) capable of calculating a delay T by the formula T = PA / v, in which PA is the stopping precision at a given level and in a given direction of movement, the value of which is recorded in the memory of the microprocessor, and v is the actual speed of the car measured by the device for measuring the speed at said level and in said direction movement, and a timer module (48) which includes said delay in the stop information, so that the stopping of the car is delayed by said delay.

Description

METHOD AND SYSTEM FOR AUTOMATIC POSITION ADJUSTMENT

STOP OF AN ELEVATOR CAB.

  The present invention relates to a system for automatically adjusting the stop position of an elevator car opposite the landing doors. Currently, the information defining the stopping altitudes at the landing doors is given by the encounter between magnetic sensors on board the cabin and a magnet fixed in the hopper at each level. This set is designated in the profession by "position reference system" (SRP). The information collected by the magnetic sensors is transmitted to the control logic with which the elevator installation is provided, which in turn gives stop orders to the means

cab drive.

  Such an SRP is illustrated by the appended FIG. I on which there is an elevator car 10 mounted in a hopper 12 and being located at a landing door 16. The hopper is provided with a magnet 18, while the cabin carries two magnetic sensors 20, 22 fixed at two different levels on a vertical channel 24. The upper sensor 20 provides the level information down and the sensor

  lower 22 provides the rising level information.

  The SRP can equip both hydraulic elevators and electric elevators of the type comprising a two-speed gear motor having two separate windings, one for carrying out the movement of the car at high speed and the other for carrying out the movement at low speed before stopping. The SRP must allow the car to be stopped at all levels opposite the landing doors, so that the difference 1 between the threshold of the cabin and that of the landing is as small as

possible, see zero.

  During mounting, the magnetic sensors and magnets are positioned at the theoretical mounting dimensions. These are calculated as a function of the nominal speed of movement of the cabin, the response time of the control logic, the parameters of detection of the magnets by the magnetic sensors and the theoretical adjustment of the motor reducer brake. However, it has been found that the theoretical mounting values almost never correspond to the reality of the installation for the following reasons: - the adjustment of the brake of the gear motor is not precise and is adopted for each installation according to the desired comfort; - the electrical sensors detect the magnets at different positions depending on the distance between them, and it is very difficult to keep this value constant at all levels; - compliance with theoretical dimensions is difficult to achieve to the millimeter; - the actual speed of movement of the cabin does not

  not exactly match the face value.

  However, it is as a function of these parameters that the magnetic sensors supply the stop information to the control logic, which translates these signals into stop orders, causing the power supply to the motor to be cut and the jaws to be released. brake for electric elevators or closing valves for hydraulic elevators. This is why, if no precautions are taken, the stopping precision which is obtained with such an SRP is poor. It is common for the thresholds of the elevator and the landing to be offset by several centimeters when stationary. To reduce this offset, it is necessary to carry out manual adjustment at each level around the theoretical value of the position of the magnetic sensors, and this in both directions of movement. But these adjustments take a long time because they require measuring the stop precision at each level in both directions of movement, to climb on the roof of the cabin to move the magnets in the right direction, to check the result and to repeat if necessary. The time taken

  making these adjustments is estimated at 10 minutes per level.

  The solution which is currently used to solve this problem consists in replacing the SRP by a device capable of giving information on the real altitude of the cabin at any time. We can thus determine the exact altitudes of the stop orders and trigger the stop orders by a program, but the drawback of this solution is that the devices capable of giving an absolute position (laser rangefinder, Stahl sensor, ribbon encoder , etc ...) are very expensive and therefore not suitable for standard two-speed or hydraulic elevators, even if they

  save time on site.

  The present invention aims to remedy these drawbacks by proposing a system for adjusting the stop position of an elevator car which does not require

  no more manual setting of magnets.

  Another object of the invention is to propose an adjustment system of this type which makes it possible to obtain precision.

almost no stop.

  These objects are achieved thanks to the adjustment system according to the invention which is of the type comprising: - magnetic sensors and magnets installed according to the theoretical mounting dimensions, as explained above, - and a stop control logic which receives l stopping information of said sensors and gives a stopping order to the drive means of the cabin, characterized in that it further comprises: - a speed measuring device making it possible to measure the speed of movement of the cabin before each stop at the different levels, - a microprocessor in which are stored in memory all the values of stop precision measured empirically at all levels, in both directions of movement of the cabin, - a stop management program able to calculate a delay T by the formula T = PA / V, in which PA is the stop precision at a given level and in a direction of movement, the value of which is noted in the microprocessor memory, and v is the actual speed of the cabin measured by the speed measuring device at said level and in said direction of movement; - And a timer module which includes said delay in the stop information given by the corresponding magnetic sensor, so that the car stop is delayed by this delay and occurs at a time when the precision

stop is practically zero.

  The invention also relates to a method for adjusting the stop precision of an elevator car, characterized in that it consists of: a) integrating into the elevator control logic a microprocessor in which are stored the values of the stop precisions for all the levels and in both directions the movement of the cabin, b) to install magnetic sensors on the cabin and magnets in the hopper, with the theoretical dimensions of assembly, c) to mount on the cabin and in the hopper a speed measuring device, which measures the speed of the cabin at a time when it is constant before stopping at a level, d) calculating the delay T = PA / v from the value of the stop precision PA for the level and the direction of movement considered, and which is noted in the memory of said microprocessor, and of the real speed v measured before arrival at said level, e) and to include this delay in the stop information that the c apteurs give to the logic of control, so that the stop is delayed of this delay and is done at a time

  o the stop precision is practically zero.

  Thanks to the invention, considerable time is saved on site when the installation is started up because it avoids climbing onto the roof of the cabin and adjusting the altitude of the magnets by trial and error. Save time

  completed is estimated at 8 minutes per level.

  Another advantage of the invention lies in the fact that the sensors and the magnets can be positioned very approximately since the errors can be corrected easily. The supports for the sensors and magnets can also be simplified by eliminating their possibility of adjustment. The time savings thus achieved

is another 5 minutes per level.

  The adjustment device according to the invention can be produced at low cost by integrating said microprocessor into the control logic with which any elevator installation is normally provided and by using as speed measuring device the optical fork speed detector making the subject of patent application no. 95 08428 filed

in the name of the same Applicant.

  The invention will be better understood on reading the

  description of an embodiment which will be made below

  with reference to the last annexes in which: FIG. 1 schematically represents an elevator provided with magnetic sensors and magnets according to the prior art; Figure 2 is a schematic view of an elevator equipped with the same sensors and magnets and also of a speed measuring device with optical fork and a system for adjusting the stop position according to the invention; and FIG. 3 is a flow chart detailing the operations carried out by the adjustment system according to the invention. Figure 1 having already been described, we will pass

  directly to the description of Figure 2. On this

  figure, there is also shown the elevator car 10, the magnet 18 fixed on the latter and the sensors

  magnetic 20, 22 fixed on the elevator car.

  When the magnetic sensors 20, 22 meet a magnet 18, they emit logic signals which are transmitted by conductors, such as 24, to a stop control unit which, advantageously, can be integrated into the control logic 26 with which the elevator installation is normally fitted. The control logic 26 for this purpose comprises an input 28 which receives magnetic sensors 20, 22 information on their meeting with the magnets 18 and an output 30 to which an order is issued

  stop sent to the drive means of the cabin.

  According to the invention, the elevator is further equipped with a device for measuring the speed of movement of the car, for example an optical fork device which is well known in the art. It will be recalled that this comprises an optical fork 32 provided with two hollow arms respectively housing an emitter and a receiver of infrared rays, the fork being fixed to the elevator car so that the arms are in a horizontal plane and that the infrared beam 34 crosses horizontally

  the interval between the arms.

  The speed measuring device also comprises a plurality of flags 36, 38 constituted by opaque plates with respect to infrared rays, said flags being fixed vertically in the hopper at the altitudes where it is desired to measure the speed of movement of the cabin, and being arranged so that they cut the infrared beam 34 each time the optical fork passes at their level. In FIG. 2, only two flags associated with a level have been represented. The upper flag 36 is used to measure the speed downhill, while the flag

  lower 38 is used to measure the climbing speed.

  The infrared radiation receiver transmits signals having a first logic state when the infrared beam passes and a second logic state when the beam is cut. These signals are transmitted by a conductor 40 to a computing unit 42 which, advantageously, can be integrated

in the control logic 26.

  From these signals, the calculation unit calculates the duration At of interruption of the infrared beam by a flag, then the speed of movement v of the cabin by the formula v = h / At, h being the height of the flag which at

cut the beam.

  The adjustment system according to the invention comprises a microprocessor 44 in which are stored in memory all the values of the stop precisions at the different levels where the stop is made, in both directions of movement, and with a load of balance on board in the cabin (approximately 45% of the nominal load). These values were previously measured during the commissioning of

the installation.

  The adjustment system also includes a stop management program 46 intended to calculate a delay T by the formula: T = PA / v in which: PA is the value of the stop precision stored in the microprocessor 44 and which corresponds at level o the stop will be effected with the balance load and for a displacement of the cabin in the direction of displacement considered; and v is the speed of movement of the cabin, measured just before stopping. It is indeed important to use the actual speed because if we were content to use the nominal speed announced by the manufacturer, we

  would add to the precision by adding the delay.

  Thus, if the elevator tends to want to stop before the level, the delay T is added to that which separates the stop information and the stop order, so that the stop order is delayed and that the final altitude of

the stop is adjusted.

  If on the contrary, the elevator tends to want to stop after the level, we cannot anticipate the stop because it is not possible to add a negative delay. To remedy this, it is sufficient to position the sensors and the magnets so that the stop information is always given well before the stop order and for

  that we can always integrate a minimum delay.

  It should be noted that the system according to the invention does not make it possible to correct the variation in the stop precision as a function of the load. The correction of the stop precision obtained is only valid for the same load conditions under which the values stored in the microprocessor have been measured. For the other load cases, the system will correct the altitude of the stop as if the on-board loading were nominal and, it will be necessary to adjust the stop precision according to the load in the cabin. This adjustment will be done as for manual adjustment

magnets.

  All the operations carried out by the logic of

  control 26 is summarized by the flow diagram of FIG. 3.

  In step 50, the magnetic sensors detect whether the elevator car has reached a stop level, and whether the

  speed became equal to the small speed before stopping.

  If not, the program is not initiated. If YES, in step 52 the calculation unit 42 calculates the duration At

  and the actual speed of movement of the cabin.

  Once the speed has been calculated, the system searches in step 54 for the value of the stop precision to be corrected for the level and the direction of movement considered, from the data stored in the microprocessor 44. This value for the precision of stop as well as the speed previously recorded in the previous step are loaded into the formula T = PA / v, then this formula is executed. The result is memorized and its value is loaded into a timer module 48 placed between the stop information

  given by the sensors 20, 22 and the stop order.

  In step 56, the system checks whether the detection of the stop information has taken place. If so, the module

  timer is started in step 58.

  In step 60, the system checks whether the timer has expired. If YES, the stop information is transferred to the

  shutdown management program in step 62.

  The Applicant tested the system according to the invention, and for this, it voluntarily positioned the magnets giving the stopping altitudes well before the presumed levels (approximately 100 mm at least) and at different values for each level. For a cabin loaded at its balance load, the correction made by the system reduced the stop precision to a value less than 2mm. By varying the load, she noticed a variation in the stop precision identical to the values measured before the installation of the system, which means that the system has no influence on the stop precision in the case

a loaded cabin.

Claims (3)

  1- Automatic adjustment system for the stop position of an elevator car, of the type comprising: - two magnetic sensors (20, 22) fixed on the car (10), one above the other, to respectively provide stop down information and stop up information, - a magnet (18) fixed in the hopper (12), said sensors and magnets being positioned according to the theoretical mounting dimensions, - and a stop control logic (26) which receives the stop information from said sensors and gives a stop order to the drive means of the cabin, characterized in that it further comprises: - a device for speed measurement (32, 36, 38) intended to measure the speed of movement of the cabin before each stop at the different levels, - a microprocessor (44) in which are stored in memory all the values of the measured stop precision PA empirically at all levels, in both directions of displacement of the c abine, - a stop management program (46) capable of calculating a delay T by the formula T = PA / V in which PA is the stop precision at a given level and in a given direction of movement, whose value is recorded in the memory of the microprocessor, and v is the real speed of the cabin measured by the device for measuring the speed at said level and in said direction of movement, - and a timer module (48) which includes said delay in the stop information given by the corresponding magnetic sensor, so that the car stop is delayed by this delay and occurs at a time when the precision stop is practically zero.   2- System according to claim 1, characterized in that the speed measuring device is constituted by an optical fork (32) fixed on the cabin (10) and   several flags (36, 38) fixed in the hopper (12).   3- A method of automatically adjusting the stop position of an elevator car by the system of claim 1, characterized in that it consists of: a) integrating into the control logic (26) of the elevator a microprocessor (44) in which the values of the stop precisions PA for all the levels are stored and in both directions the movement of the car, b) to install magnetic sensors (20, 22) on the car and magnets (18) in the hopper, at theoretical mounting dimensions, c) to be mounted on the cabin and in the hopper a speed measuring device (32, 36, 38) which measures the speed of the cabin at a time o it is constant before stopping the car at a level, d) calculating the delay T = PA / v from the value of the stop precision PA for the level and the direction of movement considered noted in the memory of said microprocessor and of the actual speed v measured before arrival at said level, e) and at include this delay in the stop information that the sensors give to the control logic, so that the stop is delayed by this delay and occurs at a time   o the stop precision is practically zero.