WO2024061766A1

WO2024061766A1 - Method for operating a lift system

Info

Publication number: WO2024061766A1
Application number: PCT/EP2023/075455
Authority: WO
Inventors: Matthias Maier; Stefan Thänert; Eduard STEINHAUER
Original assignee: Tk Elevator Innovation And Operations Gmbh
Priority date: 2022-09-23
Filing date: 2023-09-15
Publication date: 2024-03-28
Also published as: DE102022124567A1

Abstract

The invention relates to a method for operating a lift system (50), wherein the lift system (1) has a lift shaft in which at least one first lift car (51a) can travel, wherein, in order to prevent a collision of the first lift car with a collision object (51b, 52W), in particular a second lift car (51b) or a shaft end (52W), if necessary, an emergency braking of the first lift car (51a) is triggered, wherein, during normal operation, in order to initiate the emergency braking, an emergency braking path to a stopping point (SP) is calculated continuously and compared with a current distance (d) of the first lift car from the collision object (51b, 52W), wherein, during normal operation, a deceleration value (b) for the lift car is provided for the calculation, wherein the deceleration value (b1, b2, b3) provided for the calculation is variable and is determined according to a driving situation.

Description

Method for operating an elevator system

The invention relates to a method for operating an elevator system.

EP 3 224 175 B1 discloses a method for operating an elevator system with several cars. The cars are designed to move separately in different directions. The cars are each moved separately in a subsequent operation and a stop point is continuously predicted for each car at least for one direction of travel, at which the car must be able to stop if necessary. The distance between the predicted stop points of adjacent cars is continuously determined, with the elevator system being transferred to a safety mode when a negative distance between the stop points is determined. In a safety mode, emergency braking is then carried out to avoid a collision. The collision can then be safely avoided by emergency braking. For this purpose, a theoretical deceleration value for emergency braking is used mathematically.

In the event of emergency braking while traveling downwards, the passenger stands securely on his feet and can safely absorb the vertically upward braking force using his legs.

In the elevator system of the aforementioned method, emergency braking may also be necessary during upward travel or during sideways travel. However, there is a significant risk of injury when emergency braking occurs while driving upwards or sideways. In the event of an emergency braking in the lateral direction, the passengers will inevitably skid in the lateral direction; In the event of emergency braking while ascending, passengers can lose traction and be thrown headfirst into the cabin ceiling.

When applying the stop point concept, as in EP 3 224 175 B1, the deceleration value during emergency braking during sideways travel and upward travel must not be too large.

Lower deceleration values reduce the risk of injury, but in practice also result in longer stopping distances and stopping times. The car speed must therefore be adjusted early when approaching a car Collision object can be reduced in order to avoid emergency braking through the stop point concept.

EP 1 698 580 B1 discloses an elevator system. A distance determination unit is provided for determining an actual distance between the car and an obstacle, e.g. another car or the end of a shaft. A critical distance is continuously determined taking into account the current speed and the braking deceleration. If the critical distance falls below the actual distance, normal operation is exited and a transition is made to an emergency stop state in which an emergency stop brake brakes the car in a short time. In this emergency stop state, the actual distance is still monitored. If it then becomes necessary, a safety catch is initiated in the event of danger, whereby a safety gear is triggered, which can brake the car in a very short time, i.e. with an even greater delay.

It is the object of the present invention to provide an improved method for operating an elevator system.

The object on which the invention is based is achieved by a method and an elevator system according to the main claims; Refinements are the subject of the subclaims and the description.

In order to avoid the risk of possible injuries to passengers during emergency braking and at the same time to achieve normal operation as quickly as possible, different braking scenarios are now being introduced. The braking scenarios differ in the deceleration values on which the calculation is based.

During the ongoing check based on the stop point concept, it is constantly checked which deceleration value should be used as a basis for determining or calculating the need for emergency braking.

If the emergency braking were to be carried out with a large deceleration value, the stop point concept would allow the car to approach a collision object at a smaller safety distance or at an increased travel speed. If the emergency braking were to be carried out with a smaller deceleration value, the stop point concept would allow the car to approach a collision object at a greater safety distance or at a lower travel speed.

The invention now provides for the deceleration value of the emergency braking to be determined as a function of the current travel speed of the elevator car and for the emergency braking to then be carried out as required based on the determined deceleration value.

For this reason, depending on the distance between the cabin and other objects, a decision is made as to whether and with which braking scenario the cabin should be stopped. This means that, on the one hand, it can be ensured that the load on the passengers is only as high as necessary, and on the other hand, if necessary, a braking scenario with shorter stopping distances can be selected during the deceleration.

In particular, the invention provides for deceleration to be carried out with a larger deceleration value when the driving speed is low; At higher driving speeds, the deceleration is carried out with a lower delay.

It should be emphasized that the delay relates to the use of the safety brake. The safety brake is triggered if the current driving situation could become unsafe, especially if the car approaches an obstacle at too high a speed and there is a risk of a collision.

This does not affect the driving control of the car, which sets the speed of the car during normal operation.

A collision object can be, for example, a car adjacent in the shaft, a shaft end, in particular an upper shaft end of a vertical shaft or a side shaft end of a horizontal shaft.

The invention is explained in more detail using the following figures; herein shows: Figure 1 shows a detail of an elevator system according to the invention in a schematic representation;

Figure 2 shows a detail of the elevator system according to Figure 1 in a frontal view during horizontal travel of a car;

Figure 3 shows a detail of the elevator system according to Figure 1 in a frontal view during a vertical travel of two elevator cars in two different variants;

Figure 4 shows a first map for the operating parameters of emergency braking;

Figure 5 shows a second map for the operating parameters of emergency braking;

Figure 6, based on the map according to Figure 5, shows a comparison of a conventional braking process versus a braking process according to the present invention.

Figure 1 shows parts of an elevator system 50 according to the invention. The elevator system 50 includes fixed first guide rails 56, along which a car 51 can be guided, for example by means of backpack storage, and which enable the car 51 to be moved between different floors. Arrangements of such first guide rails 56, along which the car 51 can be guided, are arranged parallel to one another in two parallel shafts 52 ', 52".

The first guide rails 56 are aligned vertically in a first z-direction z1 (first shaft 52') or vertically in a second z-direction (second shaft 52"). Cars in one shaft 52' can move largely independently and unhindered by cars in the other shaft 52" on the respective first guide rails 56.

The elevator system 50 also includes fixed second guide rails 57, along which the elevator car 51 can be guided using the backpack storage. The second guide rails 57 are horizontally aligned in a y-direction, and allow the elevator car 51 to move within a floor is movable. Furthermore, the second guide rails 57 connect the first guide rails 56 of the two shafts 52 ', 52 "to one another.

The second guide rails 57 are therefore also used when moving the car 51 between the two shafts 52 ', 52", for example to carry out a modern paternoster operation.

The car 51 can be transferred from the first guide rails 56 to the second guide rails 57 and vice versa via third guide rails 58. The third guide rails 58 are rotatably movable about an axis parallel to the x direction, which is perpendicular to a yz plane which is spanned by the first and second guide rails 56, 57. The movement takes place along a predefined movement direction B. The rotation of the third guide rails is carried out using a drive, not shown in detail. The third guide rails 58 and the drive 2 are part of a transfer arrangement 1.

All guide rails 56, 57, 58 are at least indirectly attached to at least one shaft wall of the shaft 52. The shaft wall defines a stationary reference system for the shaft. The term shaft wall also includes a stationary frame structure of the shaft, which carries the guide rails. The rotatable third guide rails 58 are mounted on a rotating platform 53. The rotating platform 53 is stored by means of a storage unit 71.

Such systems are basically described in WO 2015/144781 A1, DE 10 2019 201 511 A1, DE 10 2016 211 997 A1 and DE 10 2015 218 025 A1.

The elevator system is controlled using a control device 54. This control device 54 can include a plurality of decentralized sub-control units. The control device 54 is set up to trigger emergency braking of a car.

Based on Figures 2 and 3, the stop point concept is briefly explained, which is essentially described in EP 3 224 175 B1. Please refer to this document for a detailed description. Figure 2 shows a first car 51a during horizontal travel. It is constantly checked whether, if necessary, emergency braking can be used to ensure that the first car 51a can be brought to a standstill in good time before or at the latest when a stop point SP is reached.

The calculation of the stop points is based on the following parameters:

- the current travel speed v of the first car 51a;

- a theoretical deceleration value with which the first car 51a is braked in the event of emergency braking. This underlying theoretical deceleration value can be lower than an actual deceleration value with which the emergency braking would then actually be carried out, which essentially leads to a higher safety reserve. However, the underlying theoretical delay value must never be greater than an actual delay value, since the calculation then assumes a level of security that does not actually exist.

The delay value is generally viewed as a positive value; the greater the delay, the faster the car is braked.

If the calculation shows that in the event of emergency braking and taking the above parameters into account, the first car 51a would mathematically only come to a standstill at or behind a stop point SP, emergency braking is triggered immediately.

In the example according to FIG. 2, the stopping point is defined by an end of the horizontal travel path through the shaft wall 52W, which represents the end of a horizontal elevator shaft. This stop point SP is static, which means that the stop point does not change its position.

In order to ensure safe stopping without collision with the shaft wall even in the event of a fault, a crossing path U must be provided between the rotating platform 53 and the shaft wall. In order to take the stopping distances of all braking scenarios into account, this crossing distance has so far been correspondingly large. However, in terms of building planning, this is undesirable because it requires a lot of space. In the examples according to FIG. 3, the stopping point is defined by a second car 51b. This stopping point is dynamic and changes with the movement of the two cars.

Figure 3a shows a situation in which the first car 51a and the second car 51b are moving towards each other. If both cars now initiate an emergency braking, the first car would have to come to a stop at the stop point SP shown at the latest.

Figure 3b shows a situation in which both the first car 51a and the second car 51b move upwards in the same direction. If both cars now initiate emergency braking, then in this case too the first car 51a would have to come to a stop at the marked stop point SP at the latest. However, since the second car 51b continues to move during an emergency braking, the stop point SP (viewed from the perspective of the first car 51a) can lie behind the current position of the second car 51b.

The stop points shown in Figure 3 are dynamic stop points.

The emergency braking is carried out according to the present invention using the maps of Figures 4 and 5. The stop points are calculated accordingly.

Several braking scenarios s1, s2, s3 are provided; in the present example there are three braking scenarios.

The braking scenarios essentially differ in the assigned deceleration values b1, b2, b3 (Figure 4). A first braking scenario s1 is based on a first deceleration value b1, a second braking scenario s2 is based on a second deceleration value b2 and a third braking scenario s3 is based on a third deceleration value b3.

The braking scenario is selected based on the current driving speed v. The higher the driving speed, the lower the associated deceleration value b. During the continuous calculation of the stop points, the current driving speed v is first determined; Based on the driving speed v, the deceleration value b is then determined, on the basis of which the stop points are calculated.

The map according to Figure 5 shows trigger curves for the different braking scenarios s1, s2, s3.

If, for example, the car is in a first operating state B1, the car travels at speed v1 at a distance d1 to the nearest stop point SP. There is no triggering because the distance to the stop point is sufficiently large. If the car now continues to approach the stopping point without reducing the speed (i.e. still at speed v1), a second operating point B2 is reached with the distance d2, which lies on the trigger line of the first braking scenario s1. The emergency braking is triggered.

In regular operation, however, the speed will be reduced by the regular driving control in good time before a stop point is reached, for example when approaching the end of a shaft. A third operating point B3 denotes a state of the car in which the car has already been braked to a speed v2 by the regular travel control compared to the second operating point.

The third operating point B3 is also on the (extended) trigger line of the first braking scenario s1. However, the emergency braking is not triggered because, according to the map from FIG. 4, it is no longer the first braking scenario s1 that is valid, but rather the second braking scenario s2. The car is already traveling at speed v2 too slowly for the first braking scenario, so that the second braking scenario s2 is now valid.

Triggering according to another braking scenario s2, s3 is currently not possible in the third operating point B3, since the third operating point B3 with the second speed v2 is not on or below the triggering line of the second or third braking scenario s2, s3. The fourth operating point B4 now refers to a situation in which the car is already very close to the stopping point. The car moves at a third speed v3, so that the third braking scenario from Figure 4 applies. However, since the fourth operating point B4 is still above the trigger line of the valid third braking scenario s3, no triggering occurs.

What is important is that the different braking scenarios all take place during normal operation, i.e. before emergency braking is activated. The term emergency braking also includes multi-stage safety procedures, which can include the activation of a safety gear. Emergency braking only serves as a safety backup when it is determined using the aforementioned method that the determined stopping point distance has been exceeded in normal operation.

As a comparative example, a fifth B5 operating point is shown in FIG. A distance d5 corresponds exactly to the distance d4 of the fourth operating point. The speed v5 of the fifth operating point B5 is chosen to be so low that the operating point is still just above the extended trigger curve of the first braking scenario s1. Now it can be seen that the first braking scenario s1 at distance d5 only allows a speed v5 that is well below the permissible speed d4 of the fourth operating point B4, which is still permitted by the third braking scenario s3.

The comparison between the fourth operating point B4 and the fifth operating point B5 now makes it clear that, due to the invention, the stop points SP can be approached at a significantly higher speed and do not have to be braked down to a very low speed level at an early stage. This is based on the knowledge that high deceleration values at low speeds are tolerable in normal operation. Even with a high deceleration, the risk of injury is low if the high deceleration occurs at a low driving speed. Because with a high deceleration at low speed, the passenger is only exposed to the high deceleration for a very short time.

This advantage is highlighted again in Figure 6. C shows the braking behavior without the stepped adjustment of the deceleration value. Here, curve C hugs the trigger curve of the first braking scenario from above s1 . I shows the braking behavior according to the invention. The stopping point can therefore be approached in a much more “sporty” manner, particularly in the final phase, i.e. with a higher average driving speed and greater deceleration, which on the one hand reduces travel times and on the other hand allows the dimensions of the overpass path U to be reduced.

Because braking is carried out at low speeds with a significantly greater deceleration value, the crossing path U behind a transfer unit (Figure 3a) can be made smaller. This is advantageous when planning buildings, as there is less side space available in the shafts. Emergency braking can be carried out with conventional safety brakes. Different safety brakes with different braking strengths can be connected in parallel, which are activated or deactivated depending on the braking scenario. Alternatively, a safety brake can be implemented by actively adjusting a preload spring, whereby the different deceleration values can be set.

The delay value is determined using the map from FIG. 4, which represents a stepped definition. It is also conceivable that the determination takes place continuously.

Reference symbol list

1 transfer arrangement

2 drive

50 elevator system

51 car

52 shaft

52W shaft wall

53 rotating platform

54 control device

56 fixed first guide rail

57 second fixed guide rail

58 third rotating guide rail

60 gears

61 drive shaft

62 output shaft

65 traction devices

64 Drive pinion v, v1 , v2, v3 Car travel speed d Reference distance b, b1 , b2, b3 Deceleration value

U crossing route

Claims

Expectations

1 . Method for operating an elevator system (50), wherein the elevator system

(1 ) has an elevator shaft in which at least a first elevator car (51 a) can travel, wherein in order to avoid a collision of the first elevator car with a collision object (51 b, 52W), in particular a second elevator car (51 b) or a shaft end (52W), an emergency braking of the first elevator car (51 a) is triggered if necessary, wherein during normal operation to initiate the emergency braking an emergency braking distance to a stop point (SP) is continuously calculated and compared with a current distance (d) of the first elevator car to the collision object (51 b, 52W), wherein the calculation is based on a deceleration value (b) for the elevator car, characterized in that the deceleration value (b1, b2, b3) on which the calculation is based during normal operation is variable and is determined depending on a driving situation.

2. Method according to the previous claim, characterized in that the delay value (b1, b2, b3) is determined depending on a travel speed (v1, v2, v3) of the first car.

3. Method according to the previous claim, characterized in that a first deceleration value (b1, b2) is determined when a first driving speed (v1, v2) is present, and a second deceleration value (b2, b3) is determined when a second driving speed (v2, v3) is determined, the second driving speed (v2, v3) being lower than the first driving speed (v1, v2), and where the second delay value (b2, b3) is greater than the first delay value (b1, b2). Method according to one of the preceding claims, characterized in that the collision object is the shaft end (52W) of a horizontal elevator shaft. Method according to one of the preceding claims, characterized in that, in normal operation, emergency braking is initiated on the basis of the comparison between the emergency braking distance and the distance (d) of the first car to the collision object (51b, 52W). Elevator system (50), comprising at least one fixed first guide rail (56, 57), which is fixedly aligned in a first, in particular vertical, direction; at least one fixed second guide rail (57, 56), which is fixedly aligned in a second, in particular horizontal or parallel to the first, direction; a plurality of cars (51) which are set up to move along the guide rails, at least one transfer arrangement (1) for transferring the cars from the first guide rail to the second guide rail and/or vice versa, the elevator system being operated using a method according to one of the previous claims. Elevator system (50) according to the preceding claim, comprising a control device (54) which is set up to control the elevator system, in particular using a method according to one of claims 1 to 5. Elevator system according to one of claims 5 or 6, characterized by a crossing path (U) at the end of a horizontal shaft.