METHOD FOR CONDITION MONITORING OF ELEVATOR
ROPES AND ARRANGEMENT FOR THE SAME
Field of the invention
The invention relates to condition monitoring of a rope of an elevator, which
elevator is in particular meant for transporting passengers and/or goods.
Background of the invention
In elevators, the ropes connected to the elevator car are generally guided by
rope wheels. The ropes pass around the rope wheel bending against the rim
thereof. During car travel, the ropes connected to the car continuously run
around the rope wheel. Any section of the rope that runs over the rope wheel
undergoes a bending cycle, which involves bending into a curved shape and
aa subsequent straightening. The ropes normally endure without breaking
several hundred thousandbending-cycles. However, the ropes are not allowed
to be used until they break. The ropes need to be monitored, maintained
andreplacedwith new ones early before breaking so as to avoid hazardous
situations. The need for maintenance orreplacementof ropes has been
determined either by visual inspection or by complicated algorithms
associating rope sections and determining bends undergone by each point of
rope. One method according to prior art is disclosed in a European patent
document EP2303749B1. Generally, visual inspection is troublesome and
inaccurate way of monitoring the condition of the ropes.The use of complicated
algorithms, on the other hand, leads to complicated programs, and their
implementation is likely to require additional processor capacity for the
elevator. Furthermore, algorithms according to the prior art, have necessitated
a very specific association process of associating each of plural specific rope
sections to one bending counter counting bendings of that specific rope
section. This association process, as well as the overall method has been
complicated and difficult to perform, and it produces information which is
complicated to evaluate.lt has come up a need for an efficient andsimple, yet
reasonably reliable way of determining rope condition.

Brief description of the invention
The object of the invention is, inter alia, to solve previously described
drawbacks of known solutions and problems discussed later in the description
of the invention. An object of the invention is to introduce a new method as
well as an elevatorimplementing an improved way of rope condition monitoring.
An object is, in particular, to provide a new method as well as an elevator,
which can in a simple, yet reasonably reliable way assess the condition of the
ropes of an elevator. Embodiments are presented, inter alia, where
unnecessary rope condition monitoring work can be omitted. In particular,
embodiments are presented, where at least the most critical section of each
rope is monitored indirectly, whereby direct or indirect monitoring of less critical
sections of these ropes can be omitted.
It is brought forward a new method for condition monitoring of a rope of an
elevator comprising an elevator car and a rope wheel arrangement, which rope
is connected to the elevator car and passes around at least one rope wheel
comprised in the rope wheel arrangement. The method comprises obtaining
travel data of the elevator car. The travel data is preferably such that it includes
information describing occurrence(s) of car start(s) and/or bypass(es). The
method further comprises determining based on the travel data a total number
of car visits at a predetermined landing in the path of the elevator car, which
total number is the sum of the number of starts of the elevator car away from
said predetermined landing so as to travel to any other landing irrespective of
the traveling direction, and the number of times the elevator car has bypassed
said predetermined landing without stopping irrespective of the traveling
direction. The method further comprises comparing the total number or a
multifold of the total number with a first predetermined limit value, wherein said
multifold equals to the total number multiplied with factor n wherein n equals
the number of said at least one rope wheel. The method further comprises
performing one or more predetermined action if said total number or the
multifold of the total number meets the first predetermined limit value, said one
or more action including one or more of indicating a weakened rope

condition,indicating a need for maintenance or replacement of elevator rope(s),
calculating an estimated moment of maintenance or replacement of elevator
rope(s), sending a specific or general warning signal, sending a fault signal,
sending a signal to a service center the signal indicating weakened rope
condition or a need for maintenance or a need for replacement of elevator
rope(s). The method is simple, as it takes account in a minimalistic fashion all
the relevant data that is needed to provide a number that is simple to compare
to a limit value. An advantage is, that the method does not necessitate
counting of great number of different type of occurrences, nor does it
necessitate complicated steps of discrimination. Thereby, it can use
fundamental data easily obtainable from any elevator, the data being such that
it is already available in many existing elevators. In particular, the new method
for rope condition monitoring can be carried out without need for multiple
complicated process steps. Furthermore, the method, even though very
simple, can provide reliable monitoring of rope condition. The method is
advantageous also for the reason that it is easy to implement in new and
existing elevators, and independent of the landing the visits of which are being
followed. There is no need for inspecting the ropes visually nor associating a
specific rope section to the visit number. In the simplest mode, there is no
need to determine whether during a journey of the car a particular portion
indeed passes over the rope wheel or not. Instead, it is assumed that car visits
as defined reflect the number of bends of certain rope section without need to
know specifically which rope portion this is.
In a further refined embodiment, the total number of car visits at a
predetermined landing in the path of the elevator carconsists of the sum of the
number of starts of the elevator car away from said predetermined landing so
as to travel to any other landing irrespective of the traveling direction, and the
number of times the elevator car has bypassed said predetermined landing
without stopping.
In a further refined embodiment, the predetermined landing is a lobby landing
of the building.

In a further refined embodiment, the predetermined landing is a lobby landing
of the building on which a destination call device is installed.
In a further refined embodiment, the predetermined landing is an intermediate
landing positioned between the lowermost and uppermost landings of the
eievator.
In a further refined embodiment, said predetermined landing is the entrance
lobby landing of the building.
In a further refined embodiment, the travel data is obtained at least partly from
car position data. Preferably, for this purpose said step of obtaining includes a
step of processing raw data, which is in this case car position data, so as to
generate the travel data including the aforementioned information from the car
position data.
In a further refined embodiment, the method comprises monitoring car position
so as to obtain said car position data.
In a further refined embodiment, the car position is monitored by means of a
car position sensing arrangement.
In a further refined embodiment, if said total number meets a second
predetermined limit value, which is higher than the first predetermined limit
value, the elevator is removed from passenger use.
In a further refined embodiment, said obtaining, determining and comparing
are each performed repeatedly during use of the elevator so as to accomplish
the comparison with an updated total number of car visits.
In a further refined embodiment, a cycle of said obtaining, determining and
comparing is performed repeatedly so as to accomplish the comparison with
an updated total number of car visits, repeating of this cycle preferably being
triggered every time either the car start from said predetermined landing or a
bypassing of said predetermined landing is realized.

In a further refined embodiment, said sum is determined by counting the starts
of the elevator car away from said predetermined landing so as to travel to any
other landing irrespective of the traveling direction, and the number of times
the elevator car has bypassed said predetermined landing without stopping, in
particular by increasing the sum by one each time said start or bypass occurs.
It is also brought forward a new arrangement for condition monitoring of a rope
of an elevator, which rope is connected to an elevator car and passes around
at least one rope wheel of a rope wheel arrangement. The arrangement
comprises a processing unit arranged to obtain travel data of the elevator car,
the travel data preferably including information describing occurrence(s) of car
start(s) and/or bypass(es), and to determine based on the travel data a total
number of car visits at a predetermined landing in the path of the elevator car,
which total number is the sum of the number of starts of the elevator car away
from said predetermined landing so as to travel to any other landing
irrespective of the traveling direction, and the number of times the elevator car
has bypassed said predetermined landing without stopping; and to compare
the total number of car visits obtained by said determining or a multifold of the
total number obtained by said determining with a first predetermined limit
value, wherein saicd multifold equals to the total number multiplied with factor n
wherein n equals the number of said at least one rope wheel; and to perform
one or more predetermined action if said total number or the multifold of the
total number meets the first predetermined limit value, said one or more action
including one or more of indicating a weakened rope condition,indicating a
need for maintenance or replacement of elevator rope(s), calculating an
estimated moment of maintenance or replacement of elevator rope(s), sending
a specific or general warning signal, sending a fault signal, sending a signal to
a service center the signal indicating weakened rope condition or a need for
maintenance or a need for replacement of elevator rope(s).
The elevator as described anywhere above is preferably, but not necessarily,
installed inside a building. It is of the type where the elevator car is arranged
to serve two or more landings. The car preferably responds to calls, such

asdestination calls from landing and/or destination commands from inside the
car so as to serve persons on the landing(s) and/or inside the elevator car.
Preferably, the car has an interior space suitable for receiving a passenger or
passengers, and the car can be provided with a door for forming a closed
interior space. Thereby, it is well suitable for serving passengers.
Brief description of the drawings
In the following, the present invention will be described in more detail by way of
example and with reference to the attached drawings, in which
Figure 1 illustrates schematically an elevator according to a preferred
embodiment of the invention implementing a method according to a preferred
embodiment of the invention.
Figure 2 illustrates schematically an alternative rope wheel arrangement for the
elevator of Figure 1.
Detailed description
Figure 1 illustrates an elevator implementing a method for condition monitoring
of an elevator rope I.The elevator comprises a hoistway H, and an elevator car
2 and a counterweight 4, which are vertically movable in the hoistway H. The
elevator further comprises a rope wheel arrangement M, and a roping R, which
comprises a rope i or several of them, each of which passes around a rope
wheel 3 guiding the passage of the rope 1. Said ropes 1 are in the illustrated
embodiments suspension ropes. Said rope 1 is connected to the elevator car
2, whereby the rope 1 continuously runs over the rope wheel 3 during vertical
movement of the car 2 upwards or downwards.The rope 1 passes around the
rope wheel 3 bending against the rim thereof. Thereby, any section of the rope
that runs over the rope wheel 3 undergoes a bending cycle, which involves
bending into a curved shape and a subsequent straightening.
In a first alternative, the ropel is monitored indirectly by first obtaining a total
number N of car visits at a predetermined landing in the path of the elevator
car 2 and thereafter comparing this total number N with a predetermined

limitvalue. This logic works fine regardless of how many of said rope wheels 3
the elevator has. The limit has been predetermined to suit for the specific
elevator configuration, e.g. by choosing the value for the limit from a
tablepreferably formed based on experience or tests. The value of the limit
value depends on the specifics of the rope 1 itself, but also on the
configuration of the elevator, in particular the number of rope wheels of the
rope wheel arrangement M.The aforementioned logic is most useful in case
the elevator has only one of said rope wheels 3, because in that case the total
number N is as such an approximate number of actual bending-cycles the rope
section has undergone. This is convenient as thetotal number of visits is
directly comparable with a limit value of the rope 1, which is chosen to be the
actual number of bending-cycles the rope is allowed to go through before
triggering predefined actions which are specified elsewhere in the application.
In case the elevator has several of said rope wheels 3 , the limit value,as
predetermined to suit for this specific elevator configuration, is of course for a
given rope 1 smaller than that for the elevator with only one rope wheel 3. In
particular, it is preferable that the limit value is then the actual number of
bending-cycles the rope is allowed to go through before triggering predefined
actions as divided with the number of rope wheels 3.Thereby, with several
rope wheels 3 the total number of visits is directly comparable with the limit
value of the rope 1. Furthermore, in the method, if it is found out in the
comparison that the total number N meets the first predetermined limit
value,one or more predetermined action is performed. The predetermined
action may be one or more of those given elsewhere in the application.
In a second alternative, the rope 1 is monitored indirectly by first obtaining a
total number N of car visits at a predetermined landing in the path of the
elevator car 2 and thereafter comparing a multifold of the total number N with a
predetermined limit value (also referred to as the first predetermined limit
value). Said multifold equals to the total number N multiplied with factor n
wherein n equals the number of said at least one rope wheel, whereby the
multifold can be regarded to represent an approximate number of actual

bending-cycles the rope section has undergone.This logic is especially useful
in case there are plural (i.e. 2 or more) rope wheels 3 (as illustrated in Figure
2), aswith this logic the effect of the number of rope wheels 3need not be taken
into account when choosing the limit value.This is because the multifold of the
total number N is, as such, automatically an approximate number of actual
bending-cycles the rope section has undergone. This is convenient as the
multifold of the total number of visits is directly comparable with a limit value of
the rope 1, which is the actual number of bending-cycles the rope is allowed to
go through before triggering predefined actions which are specified elsewhere
in the application. In any case, it is preferable that the limit value has been
predetermined to suit for the specific elevator configuration, e.g. by choosing
the value for the limit from a tablepreferably formed based on experience or
tests. This logic works fine also in case there are only one of said rope
wheels 3. Thus, the logic can be utilized in different elevators and the software
need not be reprogrammed for different elevators separately. Furthermore, in
the method, if it is found out in the comparison that themultifold of total number
N meets the first predetermined limit value,one or more predetermined action
is performed. The predetermined action may be one or more of those given
elsewhere in the application.
In the embodiments illustrated in Figures 1 and 2, the rope wheel arrangement
M,M' also drives the elevator car 2 under control of an elevator control unit 10.
The rope wheel arrangement M,M' in each embodiment comprises a motor 5
connected in force transmitting manner to a rope wheel 3, which is thereby
rotatable by the motor 5. The rotatable rope wheel 3 engages the rope(s) 1
passing around it with friction engagement and/or with a positive engagement,
whichever is chosen for the elevator. The rope(s) 1 is/are connected to the car
2, so the driving force needed for moving the car 2can be transmitted from the
motor 5 to the driven rope wheel 3 and from there further to the elevator car 2
via the rope(s) 1. The rope(s) 1 can be of any type, for example having a
substantially round cross-section or belt-like, and connects the elevator car 2
and the counterweight 4 to each other. In the embodiment of Figure 2, the

rope wheel arrangement M' comprises, in addition to a rope wheel driven by
the motor 5, also another rope wheel 3, which is preferably an idle wheel and
meant to guide the rope(s) to descend at a desired lateral point down from the
rope wheel arrangement M' thereby allowing the L-measurementof the elevator
to differ from diameter of the driven rope wheel 3.
The aforementioned predetermined one or more action to be performed if the
first predetermined limit value is met, may be
- indicating a weakened rope condition, and/or
- indicating a need for maintenance or replacementof elevator rope(s) 1
with new one(s), and/or
- calculating an estimated moment of maintenance or replacementof
elevator rope(s) 1 with new one(s), and/or
- sending a specific warning signal (e.g. a signal including a warning code
associated with rope(s)) or a general warning signal,
- sending a fault signal (e.g. a signal including a fault code associated
with rope(s)),
- sending a signal to a service center the signal indicating weakened rope
condition or a need for maintenance or a need for replacementof
elevator rope(s) 1 with new one(s).
After one or more of these actions has been performed, the elevator can
remain in use if there is another, higher limit value yet to be compared with the
total number. In this way, after the above given action(s) has/have been
performed, the maintenance personnel has a certain time to replace or
maintain the ropes until the second limit value is met. For this purpose, the first
limit value is chosen to be smaller than the ultimate limit of allowed total visit
number N. The steps of obtaining, determining and comparing are repeated,
e.g. in the same way as before meeting the first limit value, and if said total
number N meets a second predetermined limit value, which is higher than the
first predetermined limit value, the elevator is removed from passenger

use.When this second value is met in the comparison, it is not safe to have the
elevator any more in passenger use.
The total number N of car visits at a predetermined landing in the path of the
elevator car 2 is the sum of the number of starts of the elevator car 2away from
said predetermined landing Loso as to travel to any other landing L-1,L+1,L+2.. L-
+nirrespective of the traveling direction, and the number of times the elevator
car2 has bypassed said predetermined landingLowithout stopping, irrespective
of the traveling direction during the bypass. Thereby, the method simply takes
into account in a minimalistic fashion all the most relevant data. As there is no
necessity for any additional actions to be taken into account, no additional
numbers need to be summed to this total number. Thereby, it is preferable that
the total number N consists of the sum of the number of starts of the elevator
car2 away from said predetermined landingLoso as to travel to any other
landing L-1,L+1,L+2. L-+nirrespective of the traveling direction, and the number of
times the elevator car2 has bypassed said predetermined landingLowithout
stopping.
It is preferable, that said determination of the total number is performed not
only, once but repeatedly, i.e. updated, during the elevator use. In a simple
solution, said sum is determined by counting the starts of the elevator car2
away from said predetermined landingLoto travel to any other landing L-
1,L+1,L+2.. L-+n, irrespective of the traveling direction, as well as the number of
times the elevator car2 has bypassed said predetermined landingLowithout
stopping, in particular by increasing the sum by one each time said start or
bypass occurs. Said determination is preferably performed by a computer
program run on a processing unit, such as a microprocessor unit 11, which
preferably forms part of the elevator control 10, whereby no separate
processing unit is necessary. Said determination is preferably implemented at
least partly by a counter accumulating the starts and bypasses. The counter is
preferably provided by said computer program. Preferably, every time the sum
is increased, also the comparison is performed. Thereby, also the comparison
is performed not only once but repeatedly, i.e. updated, during the elevator

use.The comparison is preferably performed by the same computer program
as the aforementioned determination. It is preferable that all the steps of
obtaining, determining and comparing are performed repeatedlyduring the
elevator use. In particular, it is preferable that a complete cycle of said
obtaining, determining and comparing is carried out repeatedly so as to
accomplish the comparison with an updated total number N of car visits.
Preferably repeating of this cycle is triggered every time either the start of the
car2 to travel to any other landingl_-1,L+1,L+2.. L-+nfrom said predetermined
landing or a bypassing of said predetermined landing is realized.
As mentioned, the method comprises the step of obtaining travel data of the
elevator car 2, based on which travel data said determination is performed. For
making the aforementioned determination possible, the travel data obtained
includes information describing occurrence(s) of car start(s) and/orbypass(es),
particularly concerning said predetermined landing Lo. Preferably, the travel
data describes the occurrence(s) of car start(s) and/or bypass(es)in a
numerical form, whereby it is usable without or at most with minor processing
in providing the aforementioned sum. It is not necessary (although preferable)
that the travel data, as obtained, is as such useful without processing for
forming the sum. For those cases, the determination step may include a step
of processing the travel data, in particular so as to convert it into numerical
form or derive number(s) therefrom, to be used for mathematical operation of
forming the aforementioned sum.In said obtaining.the travel data including the
aforementioned information (about start(s) and/or bypass(es)) can be obtained
from one or more sources either as ready to be used in the subsequent step of
determining, or alternatively as raw data. In the latter case, said step of
obtaining further includes a step of processing raw data so as to generate the
travel data including the aforementioned information from raw data. Such raw
data can be for example data of occurred car journeys or car position data or
the likedata, e.g. in the form of statistics.
The aforementioned travel data is preferably obtainedfrom car position data,
for which purpose said step of obtaining includes a step of processing raw

data, which is in this case car position data, so as to generate the travel data
including the aforementioned information from the car position data.In the
embodiment as illustrated in Figure 1, the method further comprises a step of
monitoring car position so as to obtain the car position data. In Figure 1, it is
illustrated that the car position is monitored by means of a car position sensing
arrangement12a,12b. The position sensing arrangement 12a, 12b can be of
any type suitable for this purpose, such as one using a proximity sensor 12a
sensing whether it is level with its counterpart 12b. The car position data signal
is sent (illustrated with an arrow) from the position sensing arrangement
12a, 12b to the elevator control unit 10 and received by the elevator control unit
10, for example by the elevator controller 10' thereof, which controls the motor
5 of the elevator, and receives information of car position anyways for the
elevator control functions. In case the elevator car 2 starts away from the
predetermined landing so as to travel to any other landing L-1,L+1,L+2.. L-
+nirrespective the traveling direction, the program running on the processing
unit 11 obtains an information of occurrence of the start, i.e. said travel data,
from the elevator controller 10'.After obtaining this travel data including
informationof occurrence of the start, the total number is determined in the
manner as earlier described by the processing unit 11, preferably by a counter
provided by said program running on the processing unit 11, which increments
an accumulated total number of visits by one. Correspondingly, in case the
elevator car 2 bypasses said predetermined landing without stopping, the
program running on the microprocessor unit 11 obtains information of
occurrence of the bypass, i.e. said travel data, from the elevator controller 10'
(illustrated with an arrow). After obtainingsaidtravel data, which
includesinformation of occurrence of the start and/or the bypass, the total
number is again determined in the manner as earlier described by the
processing unit 11, preferably by a counter provided by said program running
on the processing unit 11, which increments an accumulated total number of
visits by one. Thereafter, the step of comparing follows in the way as above
described.Car position data can of course be acquired in alternative ways than
provided by the car position sensing arrangement 12a, 12b, which provides a

direct measurement of the car position. For example, the car position data can
be alternatively acquired from statistics of occurred car journeys or the like
information.
All said travel data can be obtained from one source or from several, e.g. two,
sources. For example the travel data including information describing the car
starts can be obtained from different source than the travel data including
information describing the bypasses. Each of said one or several sources can
be any source where this kind of information can be received from.
In Figure 1 an embodiment of an arrangement for condition monitoring of an
elevator rope is illustrated in accordance with the invention, wherein an
elevator rope 1 is connected to an elevator car 2 and passes around at least
one rope wheel 3. Figure 2 presents a rope wheel arrangement M' as an
alternative to that of Figure 1. The arrangement comprises a processing unit
11 arranged to obtain travel data of the elevator car 2, which travel data
includes information or statistics of car position and/or starts, and to determine
based on the travel data a total number of car visits at a predetermined landing
in the path of the elevator car 2, which total number is the sum of the number
of starts of the elevator car2 away from said predetermined landingLoso as to
travel to any other landing L-1,L+1,L+2.. L-+nirrespective of the traveling direction,
and the number of times the elevator car2 has bypassed said predetermined
landingLowithout stopping. The processing unit 11 is further arranged to
compare the total number N of car visits obtained by said determining or a
multifold of the total number N with a first predetermined limit value, wherein
said multifold equals to the total number N multiplied with factor n wherein n
equals the number of said at least one rope wheel. The arrangement,
preferably said processing unit 11 thereof, is further arranged to perform one
or more predetermined action if said total number N or the multifold of the total
number N meets the first predetermined limit value, said one or more action
including one or more of indicating a weakened rope condition, indicating a
need for maintenance or replacementof elevator rope(s) 1, calculating an
estimated moment of maintenance or replacementof elevator rope(s) 1 with

new ones, sending a signal to a service center the signal indicating weakened
rope condition or a need for maintenance or a need for replacementof elevator
rope(s) 1with new ones. With regard to the nature of the processing unit 11, it
is preferably a microprocessor unit 11, which is arranged to run a computer
program performing said steps of obtaining, determining and comparing. The
processing unit 11 preferably is in data transfer connection with the elevator
controller 10' of the elevator control unit 10, to which also said processing unit
11 preferably belongs. So as to be able to perform the comparison, the
processing unit preferably comprises a memory storing the first limit value and
possibly a second limit value as specified earlier. It preferably also stores the
program run by the processing unit 11. The processing unit 11 is preferably
furthermore in data transfer connection (not showed) or at least suitable to
establish such a connection with a means separate from said elevator, such as
a service center, so as to be able to communicate information relating to the
condition of the rope(s) 1 with said means separate from said elevator. The
arrangement is furthermore implemented the other details of the method as
described above.
It is advantageous to use in said determination of the total number of visits the
number of starts of the elevator car2away from said predetermined landing Lo
so as to travel to any other landing L-1,L+1,L+2.. L-+nirrespective of the traveling
direction. The method is thereby simple, as it does not necessitate counting
both starts and arrivals, nor any complicated discrimination of certain starts
from the sum. Simply, all starts from said predetermined landingLoso as to
travel to any other landing are included (counted) into the number of starts.
This is advantageous also for the reason that start counters are easy to
implement by a computer program running on the processing unit 11.
Furthermore, starts are in some elevators counted for other purposes. In those
elevators, the system need not be greatly modified as all the starts,
irrespective of traveling direction, can be counted into the sum.
The number of starts of the elevator car2 away from said predetermined
landingLoso as to travel to any other landing L-1,L+1,L+2.. L+nirrespective of the

traveling direction includes starts with traveling direction upwards and starts
with traveling direction downwards. Also, the number of starts of the elevator
car2 away from said predetermined landing Lo so as to travel to any other
landing irrespective of the traveling direction includes starts irrespective of
whether the traveling direction of the started run is the same or opposite to that
of the preceding run. In particular, it is preferable so as to guarantee simplicity,
the aforementioned number of starts of the elevator car2 away from said
predetermined landingLoso as to travel to any other landing includes all the
starts of the elevator car2 away from said predetermined landingLoso as to
travel to any other landing L-1,L+1,L+2.. L-+n.
The aforementioned predetermined landing is preferably a lobby landing Loof
the building. The lobby landing of the building is known to have most traffic in
most elevator systems. Particularly preferably said predetermined landingLois
the entrance lobby landing of the building, i.e. the landing on which the
exit/entrance door 14 of the building is located. Each visit of this lobby landing
Locauses bending on one and same section of each of the ropes of the
elevator. When the total visit number of the landing with most visits is used for
the purpose of rope condition monitoring, the condition of therope section with
highest number of bendings, and thereby the condition of the rope section,
which is most critical to monitor, is monitored automatically. This is performed
indirectly as no visual inspection needs to take place. Neither is it necessary to
be aware where the section of the rope is actually positioned in the length of
the rope. There is no need to associate any specific rope section to the
counted number, nor is it necessary that the actual location of the rope section
with most bendings is ever determined.In Figure 1, the predetermined landing
is a lobby landing Loof the building. The lobby landing Lois the entrance lobby
landing of the building,on which landing a destination call device 13 is
installed. Via the destination call device 13, a passenger can give the elevator
system, in particularthe elevator control unit 10 thereof, a destination call
according to which the elevator system, in particular the elevator control unit
10 thereof, allocates an elevator car to the passenger. The predetermined

landing Lo is in this case an intermediate landing positioned between the
lowermost and uppermost landings of the elevator. Thereby, starts can occur
towards either of the two traveling directions, but also bypasses are possible.
The method is in this case particularly efficient. The method taking into account
also this position of the landing of most traffic, can be implemented in any
elevator, independent of where the landing whose total visits are determined
and compared with a limit value is positioned. Thereby, the same system can
be installed to any building. The method/arrangement can be implemented for
one or more landings. Should the method be implemented for all the landings,
it can be assumed that all the rope sections that can go through considerable
bending are monitored.
As specified above, it is preferable that the aforementioned predetermined
landing isa lobby landing Lo of the building, as the lobby landing of the building
is known to have most traffic in most elevator systems. However, said
predetermined landing could in some elevator installation be chosen to be
some other landing than lobby landing, especially if that other landing is known
to have most traffic in that specific elevator system.
It is to be understood that the above description and the accompanying
Figures are only intended to illustrate the present invention. It will be apparent
to a person skilled in the art that the inventive concept can be implemented in
various ways. The invention and its embodiments are not limited to the
examples described above but may vary within the scope of the
claims.Althoughthe method/arrangement is/are illustrated in context of a
counterweighted elevator only, the method/arrangement can be utilized also
for condition monitoring of rope(s) that are not connected to a counterweight,
such as rope(s) of a counterweightless elevator.

CLAIMS
1. A method for condition monitoring of a rope (1) of an elevator
comprising an elevator car (2) and a rope wheel arrangement (M,M'),
which rope (1) is connected to the elevator car (2) and passes around at
least one rope wheel (3) comprised in the rope wheel arrangement
(M,M), characterized in that the method comprises
obtaining travel data of the elevator car (2),
determining based on the travel data a total number (N) of car
visits at a predetermined landing (Lo) in the path of the elevator car (2),
which total number (N) is the sum of the number of starts of the elevator
car (2) away from said predetermined landing(Lo) so as to travel to any
other landing (L-1,L+1,L+2.. L+n) irrespective of the traveling direction, and
the number of times the elevator car has bypassed said predetermined
landing(Lo) without stopping irrespective of the traveling direction; and
comparing the total number (N) or a multifold of the total number
(N) with a first predetermined limit value, whereinsaid multifold equals
to the total number (N) multiplied with factor n wherein n equals the
number of said at least one rope wheel (3); and
performing one or more predetermined action if said total number
(N) or the multifold of the total number (N) meets the first predetermined
limit value, said one or more action including one or more of indicating a
weakened rope condition,indicating a need for maintenance or
replacement of elevator rope(s) (1), calculating an estimated moment of
maintenance or replacementof elevator rope(s) (1), sending a specific or
general warning signal, sending a fault signal, sending a signal to a
service center the signal indicating weakened rope condition or a need
for maintenance or a need for replacementof elevator rope(s).
2. A method according claim 1, characterized in that the total number (N)
of car visits at a predetermined landing (Lo) in the path of the elevator
car (2) consists of the sum of the number of starts of the elevator car (2)

away from said predetermined landing(Lo) so as to travel to any other
landing (L-1,L+1,L+2.. L+n) irrespective of the traveling direction, and the
number of times the elevator car (2) has bypassed said predetermined
landing(Lo) without stoppingirrespective of the traveling direction.
3. A method according to any of the preceding claims, characterized in
that the predetermined landing (Lo) is a lobby landing of the building.
4. A method according to any of the preceding claims, characterized in
that the predetermined landing (Lo) is a lobby landing of the building on
which a destination call device is installed.
5. A method according to any of the preceding claims, characterized in
that the predetermined landing (Lo) is an intermediate landing positioned
between the lowermost and uppermost landings of the elevator.
6. A method according to any of the preceding claims, characterized in
that said predetermined landing(Lo) is the entrance lobby landing of the
building.
7. A method according to any of the preceding claims, characterized in
that said travel data includes information describing occurrence(s) of car
start(s) and/or bypass(es).
8. A method according to any of the preceding claims, characterized in
that the travel data is obtained at least partly from car position data.
9. A method according to any of the preceding claims, characterized in
that the method comprises monitoring car position so as to obtain car
position data.

10.A method according to any of the preceding claims, characterized in
that the car position is monitored by means of a car position sensing
arrangement (12a,12b).
11. A method according to any of the preceding claims, characterized in
that if said total number meets a second predetermined limit value,
which is higher than the first predetermined limit value, the elevator is
removed from passenger use.
12. A method according to any of the preceding claims, characterized in
that said obtaining, determining and comparing are each performed
repeatedly during use of the elevator;
13. A method according to any of the preceding claims, characterized in
that a cycle of said obtaining, determining and comparing is performed
repeatedly, repeating of this cycle preferably being triggered every time
either the car start from said predetermined landing (Lo) or a bypassing
of said predetermined landing (Lo) is realized.
14.A method according to any of the preceding claims, characterized in
that said sum is determined by counting the starts of the elevator car (2)
away from said predetermined landing(Lo) so as to travel to any other
landing (L-1,L+1,L+2.. L-+n) irrespective of the traveling direction, and the
number of times the elevator car (2) has bypassed irrespective of the
traveling directionsaid predetermined landing(Lo) without stopping, in
particular by increasing the sum by one each time said start or bypass
occurs.
15.An arrangement for condition monitoring of a rope (1) of an elevator,
which rope (1) is connected to an elevator car (2) and passes around at
least one rope wheel (3) ofa rope wheel arrangement (M,M'),
characterized in that the arrangement comprises

a processing unit (11) arranged to obtain travel data of the elevator
car (2), and to determine based on the travel data a total number (N) of
car visits at a predetermined landing (Lo) in the path of the elevator car
(2), which total number (N) is the sum of the number of starts of the
elevator car (2) away from said predetermined landing(Lo) so as to
travel to any other landing (L-1.L+1.L+z. L-+n) irrespective of the traveling
direction, and the number of times the elevator car (2) has bypassed
said predetermined landing(Lo) without stopping irrespective of the
traveling direction; and
to compare the total number (N) of car visitsobtained by said
determining or a multifold of the total number (N) obtained by said
determining with a first predetermined limit value, wherein said multifold
equals to the total number (N) multiplied with factor n wherein n equals
the number of said at least one rope wheel (3);and
to perform one or more predetermined action if said total number
(N) or the multifold of the total number (N) meets the first predetermined
limit value, said one or more action including one or more of indicating a
weakened rope condition.indicating a need for maintenance or
replacement of elevator rope(s) (1), calculating an estimated moment of
maintenance or replacement of elevator rope(s) (1), sending a specific
or general warning signal, sending a fault signal, sending a signal to a
service center the signal indicating weakened rope condition or a need
for maintenance or a need for replacementof elevator rope(s) (1).