Patent Description:
Typically, elevator related data may be obtained for example for remote maintenance and/or elevator usage monitoring purposes from internal buses and/or control units of an elevator system. However, for example in case of third-party elevator systems, there may not be access to the internal buses and/or control units for obtaining the elevator related data for the monitoring purposes. A monitoring unit comprising one or more internal or external sensor devices may be arranged to the elevator system to obtain the elevator related data. For example, the monitoring unit may be arranged to an elevator car travelling along an elevator shaft. However, it may not be possible to cover all failure cases with said monitoring unit. Moreover, especially in the elevator systems, where the monitoring unit is traveling on the elevator car along the elevator shaft, addition of one or more further sensor devices residing for example inside the elevator shaft and/or a machine room by simply wiring the sensor devices to the monitoring unit would be very expensive and sometimes even not possible.

Document <CIT> discloses a Bluetooth wireless communication system and method for communication in an elevator hoistway. This document is seen as being the closest prior art document of the present invention and discloses the preamble of claim <NUM>.

Document <CIT> discloses an elevator system comprising and elevator shaft, an elevator car, and a synchronous wireless mesh network comprising plurality of node devices and a gateway device.

Thus, there is need to develop further solutions to improve monitoring of an elevator system.

An objective of the invention is to present an elevator monitoring system, a method and an elevator system for monitoring an elevator system. Another objective of the invention is that the elevator monitoring system, the method and the elevator system for monitoring an elevator system improve monitoring of an elevator system.

The objectives of the invention are reached by an elevator monitoring system, a method and an elevator system as defined by the respective independent claims.

According to a first aspect, an elevator monitoring system for monitoring an elevator system is provided, wherein the elevator monitoring system comprises a wireless mesh network comprising: a first group of node devices comprising a plurality of node devices configured to be constantly on and to be able to participate relaying elevator related monitoring data; a second group of node devices comprising a plurality of node devices, at least one of the plurality of node devices belonging to the second group of node devices is configured to relay elevator related monitoring data from at least one other node device belonging to the second group of node devices, when the second group of node devices are on; and a control node device configured to control the second group of node devices to turn on and to enter a sleep state on demand.

One of the plurality of node devices belonging to the first group of node devices may be the control node device.

Alternatively or in addition, the control node device may be a gateway device of the wireless mesh network.

One or more of the plurality of node devices belonging to the first group of node devices and/or one or more of the plurality of node devices belonging to the second group of node devices may be associated with at least one sensor device configured to obtain elevator related monitoring data.

Each node device being associated with the at least one sensor device may be able to provide the obtained elevator related monitoring data to be relayed via the wireless mesh network at any time, when said node device is on.

The control node device may be configured to control the on demand turning on and entering the sleep state of the second group of the node devices according to one or more elevator system related parameters and/or one or more monitoring data related parameters.

The one or more elevator system related parameters may comprise one or more movement parameters representing movement of the elevator car.

The one or more monitoring data related parameters may comprise need of a specific type of elevator related monitoring data, amount of data to be relayed, and/or need of battery status data of the plurality of node devices belonging to the second group of node devices.

The plurality of node devices belonging to the first group of node devices may be powered by mains.

The plurality of node devices belonging to the second group of node devices may be powered by one or more batteries.

According to a second aspect, a method for monitoring an elevator system with an elevator monitoring system is provided, wherein the elevator monitoring system comprises a wireless mesh network comprising: a first group of node devices comprising a plurality of node devices being constantly on and being able to participate relaying elevator related monitoring data; a second group of node devices comprising a plurality of node devices, at least one of the plurality of node devices belonging to the second group of node devices relays elevator related monitoring data from at least one other node device belonging to the second group of node devices, when the second group of node devices are on; and a control node device, wherein the method comprises: controlling, by the control node device, the second group of node devices to turn on and to enter a sleep state on demand.

One or more of the plurality of node devices belonging to the first group of node devices and/or one or more of the plurality of node devices belonging to the second group of node devices may be associated with at least one sensor device for obtaining the elevator related monitoring data.

The control node device may control the on demand turning on and entering the sleep state of the second group of the node devices according to one or more elevator system related parameters and/or one or more monitoring data related parameters.

According to a third aspect, an elevator system is provided, wherein the elevator system comprises: an elevator car configured to travel along an elevator shaft, and an elevator monitoring system as described above.

The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated and this within the scope of the appended claims.

<FIG> illustrates schematically an example of an elevator system <NUM>. The elevator system <NUM> comprises an elevator shaft <NUM>, an elevator car <NUM>, and an elevator monitoring system <NUM>. The elevator shaft <NUM> may comprise one or more parts 102a, 102b. In the example of <FIG> the elevator shaft <NUM> comprises a vertical part 102a along which the elevator car <NUM> is configured to travel between a plurality of landings. The elevator shaft <NUM> may further comprise a horizontal part 102b. The horizontal part 102b of the elevator shaft <NUM> is optional and thus illustrated with dashed line in the example of <FIG>. The elevator system <NUM> may further comprise one or more elevator entities, e.g. a control unit <NUM>, an elevator hoisting machine, etc.. The control unit <NUM> may be configured to control at least the operation of the elevator system <NUM>, e.g. control the elevator hoisting machine to drive the elevator car <NUM> along at least part of the elevator shaft 102a between landings. For sake of clarity the elevator hoisting machine the one or other elevator entities are not shown in <FIG>. The elevator control unit <NUM> may e.g. be arranged to a machine room <NUM> of the elevator system <NUM>. In the example of <FIG> a non-limiting example location of the machine room <NUM> is illustrated. In the example of <FIG> the machine room <NUM> locates above the vertical part of the elevator shaft 102a, i.e. top of a building. Alternatively, the machine room <NUM> may locate for example next to the vertical part of the elevator shaft 102a, i.e. inside the elevator shaft wall. Alternatively, the elevator system <NUM> may be a machine room-less elevator system, wherein the elevator control unit <NUM> may be arranged inside the elevator shaft <NUM>.

The elevator monitoring system <NUM> is configured to monitor the elevator system <NUM>. The monitoring of the elevator system <NUM> by the elevator monitoring system <NUM> may comprise obtaining elevator related monitoring data as will be described. The elevator related monitoring data may be obtained for example for remote maintenance and/or elevator usage monitoring purposes of the elevator system <NUM>. The elevator monitoring system <NUM> enables monitoring of third-party elevator systems <NUM>, where there may not be access to internal buses and/or control units of the elevator system <NUM>. <FIG> illustrates an example of the elevator monitoring system <NUM>. For sake of clarity the entities of the elevator system <NUM> are not shown in <FIG>. The elevator monitoring system <NUM> comprises a wireless mesh network <NUM> comprising a first group 206a of node devices and a second group 206b of node devices, and a control node device <NUM>. One of the plurality of node devices 106a belonging to the first group 206a of node devices may be the control node device <NUM> as illustrated in the example of <FIG>. In other words, one of the plurality of node devices 106a belonging to the first group 206a of node devices may operate as the control node device <NUM>. The first group 206a of node devices comprises a plurality of node devices 106a configured to be constantly, i.e. always, on, i.e. in operation. In other words, the first group 206a of node devices form a constantly on part of the wireless mesh network <NUM>. The plurality of node devices 106a belonging to the first group 206a of node devices are able to participate relaying elevator related monitoring data as will be described later. The plurality of node devices 106a belonging to the first group 206a of node devices may be powered by mains, e.g. by wall plug. The second group 206b of node devices comprises a plurality of node devices 106b. The second group 206b of node devices are configured to be on, i.e. in operation, and in a sleep state on demand as will be discussed later. In other words, turning on and entering the sleep state of the second group 206b of node devices are command-based operations. The on demand turning on and entering the sleep state of the second group 206b of node devices are controlled by the control node device <NUM> as will be described later. The plurality of node devices 106b belonging to the second group 206b of node devices may form one cell of the wireless mesh network <NUM>. The plurality of node devices 106b belonging to the second group 206b of node devices are able to participate relaying the elevator related monitoring data, when the second group 206b of node devices are on, as will be described later. In other words, the plurality of node devices 106b belonging to the second group 206b of node devices are not able to participate relaying elevator related monitoring data during the sleep state. At least one of the plurality of node devices 106b belonging to the second group 206b of node devices is configured to relay elevator related monitoring data from at least one other node device 106b belonging to the second group 206b of node devices, when the second group 206b of node devices are on. When the second group 206b of node devices are entered the sleep state, one or more entities of the plurality of node devices 106b, e.g. processing unit <NUM>, communication unit <NUM>, and/or at least one sensor device <NUM>, may be switched off. Being in the sleep state reduces the power consumption of the plurality of node devices 106b belonging to the second group of node devices 206b. The plurality of node devices 106b belonging to the second group 206b of node devices may be powered by one or more batteries. In other words, the plurality of node devices 106b belonging to the second group 206b of node devices may be battery operated node devices. Therefore, the second group 206b of node devices form a battery-operated part of the wireless mesh network <NUM>.

Each of the plurality of node devices 106a, 106b of the wireless mesh network <NUM>, either belonging to the first group 206a of node devices or to the second group 206b of node devices, may provide information representing its powering technique, i.e. whether the node device is powered by mains or by one or more batteries, to the control node device <NUM>. This enables that the control node device <NUM> is aware, i.e. knows, which node devices of the wireless mesh network <NUM> are powered by mains, i.e. belong to the first group 206a of node devices, and which node devices of the wireless mesh network <NUM> are battery operated, i.e. belong to the second group 206b of node devices. Alternatively or in addition, each of the plurality of node devices 106b belonging to the second group 206b of node devices may provide battery status data representing its battery charge to the control node device <NUM> when being on.

The plurality of node devices 106a belonging to the first group 206a of node devices may be communicatively coupled with each other. The communication between the plurality of node devices 106a belonging to the first group 206a of node devices may be bi-directional. The plurality of node devices 106b belonging to the second group 206b of node devices may be communicatively coupled with each other. The communication between the plurality of node devices 106b belonging to the second group 206b of node devices may be bi-directional. At least one of the plurality of node devices 106b belonging to the second group 206b of node devices is communicatively coupled with at least one of the plurality of node devices 106a belonging to the first group 206a of node devices. The communication between the at least one of the plurality of node devices 106b belonging to the second group 206b of node devices and the at least one of the plurality of node devices 106a belonging to the first group 206a of node devices may be bi-directional.

In the example of <FIG> the plurality of node devices 106a belonging to the first group 206a of node devices, the plurality of node devices 106b belonging to the second group of node devices, and the control node device <NUM> forming the wireless mesh network <NUM> of the monitoring system <NUM> are illustrated. At least some of the plurality of node devices 106a, 106b may be arranged inside the elevator shaft <NUM>, e.g. inside the vertical part 102a of the elevator shaft <NUM> and/or inside the horizontal part 102b of the elevator shaft <NUM>. Alternatively or in addition, one or more node devices of the plurality of node devices 106a, 106b may be arranged to the elevator car <NUM> travelling along at least part of the elevator shaft 102a. Alternatively or in addition, one or more node devices of the plurality of node devices 106a, 106b may be arranged inside the machine room <NUM>. Alternatively or in addition, one or more node devices of the plurality of node devices 106a, 106b may be arranged to one or more landings (for sake of clarity the landings are not illustrated in <FIG>). In the example of <FIG> non-limiting examples of the locations of the plurality of node device 106a, 106b within the elevator system <NUM> are illustrated. The control node device <NUM> may preferably be arranged to the elevator car <NUM> of the elevator system <NUM>, e.g. to a roof top of the elevator car <NUM>, as illustrated in the example of <FIG>. Alternatively, the control node device <NUM> may be arranged to any other location within the elevator system <NUM> as long as the control node device <NUM> has a constant connection to at least one node device 106a belonging to the first group 206a of node devices arranged to the elevator car <NUM>, e.g. to the roof top of the elevator car <NUM>.

The monitoring system <NUM> may further be associated with at least one external unit <NUM> e.g. a cloud server, any other external server, the control unit <NUM> of the elevator system <NUM>, and/or a group control unit of the elevator system <NUM>. The monitoring system further comprises a gateway device <NUM>, which operates as a gateway between the wireless mesh network <NUM> and the at least one external unit <NUM>. In other words, the gateway device <NUM> may be configured to provide data, e.g. the elevator related monitoring data or any other data, from the wireless mesh network <NUM>, e.g. from one or more node devices 106a, 106b of the wireless mesh network <NUM>, to the at least one external unit <NUM> and/or from the at least one external unit <NUM> to the wireless mesh network <NUM>, e.g. to one or more node devices 106a, 106b of the wireless mesh network <NUM>. The gateway device <NUM> may be arranged to the elevator car <NUM> of the elevator system <NUM>, e.g. to the roof top of the elevator car <NUM>. Alternatively, the gateway device <NUM> may be arranged e.g. inside the machine room <NUM> of the elevator system <NUM> or to any other location within the elevator system <NUM>. According to an example, one of the plurality of node devices 106a belonging to the first group 206a of node devices may be the gateway device <NUM>, i.e. operate as the gateway device <NUM> of the wireless mesh network <NUM>. Alternatively or in addition, the control node device <NUM> may be the gateway device <NUM> of the wireless mesh network <NUM> as illustrated in the example of <FIG> illustrates another example of the elevator monitoring system <NUM>. The example elevator monitoring system <NUM> of <FIG> is otherwise similar to the above described elevator monitoring system <NUM> illustrated in <FIG>, but in the example elevator monitoring system <NUM> of <FIG> one node device 106a belonging to the first group 206a of node devices is the control node device <NUM> and another node device 106a belonging to the first group 206a of node devices is the gateway device <NUM>. In the example elevator monitoring system <NUM> of <FIG> one node device 106a belonging to the first group 206a of node devices is the control node device <NUM> and the gateway device <NUM>.

As discussed above, the control node device <NUM> is configured to control, e.g. command, the second group of node devices 106b to turn on, i.e. wake up, and to enter the sleep state on demand, i.e. according to a need defined by the control node device <NUM>. In other words, the operation (i.e. the turning on and entering the sleep state) of the second group 206b of node devices is command based operation controlled by the control node device <NUM>. The control node device <NUM> may send to the plurality of node devices 106b belonging to the second group 206b of node devices a message, e.g. a broadcast message, comprising a command, i.e. an instruction, to enter the sleep state and to turn on, i.e. wake up, after being in the sleep state. For example, the message may comprise a command for the plurality of node devices 106b belonging to the second group 206b of node devices to enter the sleep state during a certain, i.e. specific, period of time and to turn on after expiration of said certain period of time. The certain period of time may be defined by the control node device <NUM>. This command-based operation enables that all the plurality of node devices 106b belonging to the second group 206b of node devices wake up at the same time and that all the plurality of node devices 106b belonging to the second group 206b of node devices enter the sleep state at the same time. This enables that a synchronization of the is not needed. According to an example, the control node device <NUM> may control the second group 206b node devices to enter the sleep state immediately, i.e. instantly after receiving the command from the control node device <NUM>. Alternatively, the control node device <NUM> may control the second group 206b node devices to enter the sleep state delayed, i.e. at a later instant of time after receiving the command from the control node device <NUM>.

The control node device <NUM> may control the on demand turning on and entering the sleep state of the second group 206b of the node devices according to one or more elevator system related parameters and/or one or more monitoring data related parameters. The one or more elevator system related parameters may comprise one or more movement parameters representing movement of the elevator car <NUM>. The one or more movement parameters representing the movement of the elevator car <NUM> may comprise e.g. speed data of the elevator car <NUM>, acceleration data of the elevator car <NUM>, and/or location data of the elevator car <NUM>. The control node device <NUM> may be configured to obtain the one or more movement parameters from at least one sensor device <NUM> with which the control node device <NUM> is associated with or from at least one node device 106a belonging to the first group of node devices being associated with at least one sensor device <NUM>. At least the node device <NUM>, 106a (either the control node device <NUM> itself or the at least one node device 106a belonging to the first group 206a of node devices) which is associated with the at least one sensor device <NUM> is arranged to the elevator car <NUM>. For example, if the control node device <NUM> itself is associated with the at least one sensor device <NUM>, the node device <NUM> is arranged to the elevator car <NUM>. Alternatively, if the at least one node device 106a belonging to the first group 206a of node devices is associated with the at least one sensor device <NUM>, at least the at least one node device 106a belonging to the first group 206a of node devices is arranged to the elevator car <NUM>. In this case the control node device <NUM> itself may also be arranged to the elevator car or to any other location within the elevator system <NUM> as long as the control node device <NUM> has a constant connection to the at least one node device 106a belonging to the first group 206a. The at least one sensor device <NUM> may comprise e.g. at least one accelerometer, at least one magnetometer, at least one gyroscope, etc. The control node device <NUM> may further control the turning on demand turning on and entering the sleep state of the second group 206b of the node devices according to one or more learned movement parameters of the elevator car <NUM>. This enables that the control node device <NUM> may schedule the turning on demand turning on and entering the sleep state of the second group 206b of node devices according to the one or more learned movement parameters of the elevator car <NUM>. According to an example, when the elevator car <NUM> is moving, substantially a lot of elevator related monitoring data representing for example movement of the elevator car <NUM> may be needed to be monitored and thus relayed by the wireless mesh network <NUM> causing e.g. that more node devices operating e.g. in a sensor role, may be needed. Alternatively or in addition, the movement of the elevator car <NUM> may change the topology of the wireless mesh network <NUM>, causing that more node devices, e.g. operating in a router role, may be needed to improve the reliability of the wireless mesh network <NUM>. Thus, the control node device <NUM> may control the second group 206b node devices to turn on, when the elevator car <NUM> is moving and/or to enter the sleep state, when the elevator car <NUM> is not moving. For example, after the movement of the elevator car <NUM>, the control node device <NUM> may control the second group 206b node devices to enter the sleep state during a specific period of time, e.g. during opening and closing of elevator doors, and to turn on after said specific period of time, e.g. after opening and closing of the elevator doors. The one or more monitoring data related parameters may comprise need of a specific type of elevator related monitoring data, amount of data to be relayed, and/or need of battery status data of the plurality of node devices belonging to the second group 206b of node devices.

For example, the control node device <NUM> may control the second group 206b node devices to be on until all relevant data is received by the control node device <NUM>. According to another example, the control node device <NUM> may control the second group 206b node devices to be on at certain time intervals, e.g. every x seconds, to provide the battery status data to the control node device <NUM> and to be in the sleep state between said certain time intervals. According to another example, the control node device <NUM> may control the second group 206b node devices to be on at certain time intervals, e.g. every x seconds, to obtain specific type elevator related monitoring data, e.g. temperature data, oil level data, etc., and to be in the sleep state between said certain time intervals.

One or more of the plurality of node devices 106a belonging to the first group 206a of node devices and/or one or more of the plurality of node devices 106b belonging to the second group 206b of node devices may be associated with at least one sensor device <NUM> configured to obtain the elevator related monitoring data to be relayed by the wireless mesh network <NUM>. With the expression "associated with at least one sensor device <NUM>, <NUM>" is meant in this context that the node device 106a, 106b may comprise the at least one sensor device <NUM>, <NUM> and/or may be communicatively coupled to the at least one sensor device <NUM>, <NUM>, wherein the communicative coupling, i.e. connection, may be based on any know communication technology, either wired or wireless. The one ore more node devices 106a, 106b belonging to the first group 206a of node devices and/or to the second group 206b of node devices associated with the at least one sensor device <NUM> are operating in a sensor role. Some examples of different type sensor devices <NUM> are discussed later in this application. According to an example, the at least one sensor device <NUM> may be configured to obtain the elevator related monitoring data constantly. Alternatively, the at least one sensor device <NUM> may be configured to obtain the elevator related monitoring data during at least one monitoring period. Duration of the at least one monitoring period may be node device specific and/or sensor device specific. Alternatively, the duration of the at least one monitoring period of two or more sensor devices <NUM> of one node device 106a, 106b may be the same. Alternatively, the duration of the at least one monitoring period of at least one sensor device <NUM> of two or more node devices 106a, 106b may be the same. <FIG> illustrates schematically an example of an elevator system <NUM>, wherein two node devices 106a, 106b (one node device 106a belonging to the first group 206a of node devices and one node device 106b belonging to the second group 206b of node device) each is associated with at least one sensor device <NUM>. The example of <FIG> illustrates only one non-limiting example and there may be any other number or node devices 106a, 106b that may be associated with at least one sensor device <NUM>. Moreover, there may be any other number of node devices 106a belonging to the first group 206a of node devices that may be associated with at least one sensor device <NUM> and/or any other number of node devices 106b belonging to the second group 206b of node devices that may be associated with at least one sensor device <NUM>. Alternatively or in addition, the elevator system <NUM> may comprise any other elevator entities than illustrated in the example of <FIG>, e.g. one or more entities discussed above referring to <FIG>.

Alternatively or in addition, one or more of the plurality of node devices 106a belonging to the first group 206a of node devices and/or one or more of the plurality of node devices 106b belonging to the second group 206b of node devices may be configured to operate in a router role, in which the node device 106a, 106b participate relaying elevator related monitoring data sent by another node device 106a, 106b. In other words, the wireless mesh network <NUM> may comprise one or more node devices 106a, 106b (belonging to the first group 206a of node devices and/or to the second group 206b of node devices) operating only in the router role, one or more node devices 106a, 106b (belonging to the first group 206a of node devices and/or to the second group 206b of node devices) operating only in the sensor role, and/or one or more node devices 106a, 106b (belonging to the first group 206a of node devices and/or to the second group 206b of node devices) operating in the router role and in the sensor role.

The wireless mesh network <NUM> is configured to relay, i.e. deliver or provide, the elevator related monitoring data from the one or more node devices 106a, 106b (belonging to the first group 206a of node devices and/or to the second group 206b of node devices) being associated with the at least one sensor device <NUM>, i.e. operating in the sensor role, to the gateway device <NUM>. As discussed above, the gateway device <NUM> may then be configured to provide the elevator related monitoring data relayed via the wireless mesh network <NUM> to the at least one external unit <NUM>. The relaying the data, e.g. the elevator related monitoring data, via or by the wireless mesh network <NUM> means that the data transmitted, i.e. send, by one node device 106a, 106b is relayed by a node device 106a, 106b to a node device 106a, 106b until the data reaches the node device <NUM>, 106b or the gateway device <NUM> to which the data is intended. In other words, the data may be relayed via the wireless mesh network <NUM> by a node device 106a, 106b to a node device 106a, 106b until the data reaches the node device 106a, 106b or the gateway device <NUM> to which the data is intended. As discussed above, the first group 206a of node devices are constantly on and able to participate to the relaying of the elevator related monitoring data. In other words, the first group 206a of node devices operate in an asynchronous mode, in which data may be send and/or delivered at any given time. The second group of 206b node devices are able to participate to the relaying of the elevator related monitoring data when the second group 206b of node devices are on. When the control node device <NUM> controls the second group of 206b node devices to turn on, the full wireless mesh network <NUM> operates in the asynchronous mode. In other words, each node device 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, is able to participate to the relaying of the elevator related monitoring data, when said node device 106a, 106b is on.

The elevator related monitoring data may be included for example in a data packet, which is relayed via the wireless mesh network <NUM> from the one or more node device 106a, 106b of to the gateway device <NUM>. The wireless mesh network <NUM> may also be configured to relay data from the gateway device <NUM> to at least one node device 106a, 106b. The data relayed by the wireless mesh network <NUM> may preferably be the elevator related monitoring data, but also any other data may be relayed via the wireless mesh network <NUM>. The plurality of node devices 106a belonging to the first group 206a of node devices and the plurality of node devices 106b belonging to the second group 206b of node devices may use the same radio protocol. Non-limiting example radio protocols for the communication between the plurality of node devices 106a, 106b and the gateway device <NUM> may be any known asynchronous protocol, for example, but not limited to, Bluetooth Mesh, Wi-fi Mesh, or Thread Mesh. Each node device 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, being associated with the at least one sensor device <NUM> may be able to provide, e.g. send, the obtained elevator related monitoring data to be relayed to the gateway device <NUM> via the wireless mesh network <NUM> at any time, when said node device 106a, 106b is on. Thus, there is no co-operation between the node devices 106a, 106b on when they are meant to send the obtained elevator related monitoring data, as for example in traditional synchronous wireless mesh networks, in which each node device has its own prescheduled timeslot when it is allowed to send data and/or each node device is informed exactly how long and when the node device needs to be on. Because all node devices 106b belonging to the second group 206b of node devices are configured to turn on at the same time and enter the sleep state at the same time, it makes the protocol substantially simple since the node devices 106b associated with the at least one sensor device <NUM> do not need to inform beforehand how much data they might want to send in future. Instead, the control node device <NUM> may decide, if all relevant data is received or not, and finally control the second group 206b of node devices to enter back to sleep state again. This means that from asynchronous wireless mesh network perspective, the node devices 106b belonging to the second group 206b of node devices drop from the wireless mesh network <NUM> completely during the sleep states, and rejoin and form the full asynchronous wireless mesh network <NUM> again after turning on.

According to an example, the at least one sensor device <NUM> may be configured to obtain the elevator related monitoring data during periodic monitoring periods. In other words, the at least one sensor device <NUM> may be configured to perform periodic monitoring periods during which the elevator related monitoring data may be obtained. The monitoring periods may be performed at regular or irregular periods. If the node device associated with the at least one sensor device <NUM> is a node device 106b belonging to the second group 206b of node devices, the at least one sensor device <NUM> may be configured to obtain the elevator related monitoring data when the second group 206b of node devices are on. Alternatively or in addition, the at least one sensor device <NUM> may be configured to obtain the elevator related monitoring data also when the second group 206b of node devices are in the sleep state.

The one or more node devices 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, being associated with the at least one sensor device <NUM> may be configured to provide the obtained elevator related monitoring data via the wireless mesh network <NUM> after each monitoring period. Alternatively, the one or more node devices 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, being associated with the at least one sensor device <NUM> may be configured to buffer, i.e. store, the elevator related monitoring data obtained during one or more of the at least one monitoring period and to provide the buffered elevator related monitoring data to the gateway device <NUM> via the wireless mesh network <NUM> after several monitoring periods. The buffered elevator related monitoring data may comprise elevator related monitoring data obtained during several monitoring periods. In other words, the one or more node devices 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, being associated with the at least one sensor device <NUM> may be configured to obtain elevator related monitoring data during several monitoring periods and provide the elevator related monitoring data obtained during the several monitoring periods to the gateway device <NUM> at once, for example in one data packet. The buffered elevator related monitoring data may be stored e.g. to a memory unit <NUM> of said node device 106a, 106b.

According to an example, the at least one sensor device <NUM> may be communicatively coupled via at least one communication interface to the elevator system <NUM>, e.g. the elevator control unit <NUM> and/or at least one control bus of the elevator system <NUM>, to obtain the elevator related monitoring data from the elevator system <NUM>. The communicatively coupling the at least one sensor device <NUM> to the elevator control unit <NUM> may be based on a wired communication technology. Alternatively or in addition, the communicatively coupling the at least one sensor device <NUM> to the at least one control bus of the elevator system <NUM> may be based on a non-invasive data obtaining with e.g. a control bus reading device. The at least one sensor device <NUM> communicatively coupled to the elevator system <NUM> enables delivery of data obtained from the elevator system <NUM> via the wireless mesh network <NUM> to the gateway device <NUM>. Alternatively or in addition, data may be delivered via the wireless mesh network <NUM> from the gateway device <NUM> to the elevator system <NUM>, e.g. to the elevator control unit <NUM>. For example, the at least one sensor device <NUM> communicatively coupled to the elevator system <NUM> may comprise an interface for initiating a remote elevator call.

According to another example, the at least one sensor device <NUM> may comprise at least one wireless call button comprising a sensor device configured to obtain data representing generation of an elevator call. The wireless mesh network <NUM> may be used to relay the data representing generation of the elevator call from the wireless call button via the gateway device <NUM> to the external entity <NUM>, e.g. the elevator control unit <NUM>, the cloud server or the elevator group control unit. According to another example, the at least one sensor device <NUM> may alternatively or in addition comprise at least one oil level sensor device configured to obtain data representing oil level in a hydraulic oil elevator system. In the hydraulic oil elevator systems, the oil tank may typically be far away from the elevator car <NUM> and thus also far away from the gateway device <NUM> arranged e.g. to the elevator car <NUM> or inside the machine room <NUM>. The wireless mesh network <NUM> may be used to relay the data representing oil level from the oil level sensor device to the gateway device <NUM>. According to yet another example, the at least one sensor device <NUM> may alternatively or in addition comprise at least one movement sensor device arranged inside the elevator shaft 102a, 102b configured to data representing detection of someone entering the elevator shaft 102a, 102b. According to yet another example, the at least one sensor device <NUM> may alternatively or in addition comprise at least one water sensor device configured to obtain data representing detection of water in the bottom of the elevator shaft 102a, 102b, i.e. a pit of the elevator shaft 102a, 102b. According to yet another example, the at least one sensor device <NUM> may alternatively or in addition comprise at least one temperature sensor device configured to obtain data representing temperature e.g. inside the elevator shaft 102a, 102b, inside the elevator car <NUM>, and/or inside the machine room <NUM>. According to yet another example, the at least one sensor device <NUM> may alternatively or in addition, comprise at least one accelerometer, at least one magnetometer, and/or at least one gyroscope configured to obtain data representing the movement of the elevator car <NUM>.

<FIG> schematically illustrates an example of components of the node device 106a belonging to the first group 206a of node devices and/or being the control node device <NUM>. The node device 106a, <NUM> may comprise a processing unit <NUM> comprising one or more processors, a memory unit <NUM> comprising one or more memories, and a communication unit <NUM> comprising one or more communication devices. The mentioned elements of may be communicatively coupled to each other with e.g. an internal bus. The one or more processors of the processing unit <NUM> may be any suitable processor for processing information and control the operation of the node device 106a, <NUM> among other tasks. The memory unit <NUM> may store portions of computer program code <NUM>, and any other data, and the processing unit <NUM> may cause the node device 106a, <NUM> to operate as described by executing at least some portions of the computer program code <NUM> stored in the memory unit <NUM>. In other words, the computer program code <NUM> may comprise instructions, which when the program is executed by a computer, e.g. the node device 106a, <NUM>, cause the node device 106a, <NUM> to carry out the operations of the node device 106a, <NUM> as described above. Furthermore, the one or more memories of the memory unit <NUM> may be volatile or non-volatile. Moreover, the one or more memories are not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the invention. The operations of the node device 106a, <NUM> may also be implemented with a microcontroller solution with embedded software. The communication unit <NUM> may be based on at least one known communication technologies, either wired or wireless, in order to exchange pieces of data as described earlier. The communication unit <NUM> provides an interface for communication with any external unit, such as one or more other node devices 106a, 106b, <NUM> of the wireless mesh network <NUM>, the at least one sensor device <NUM>, the gateway device <NUM>, any databases and/or any external systems. The communication unit <NUM> may comprise one or more communication devices, e.g. radio transceiver, antenna, etc. As discussed above, at least one node device of the plurality of node devices 106a, <NUM> may comprise the at least sensor devices <NUM> for obtaining the elevator system related data. As discussed above, the node device 106a, <NUM> may further comprise at least one sensor device <NUM> for obtaining one or more movement parameters representing movement of the elevator car <NUM>. The node device 106a, <NUM> may possibly further comprise a user interface comprising I/O devices, such as buttons, keyboard, touch screen, microphone, loudspeaker, display and so on, for receiving input and outputting information. As described above, the power for the node device 106a, <NUM> belonging to the first group 206a of node devices may be provided from the mains via a plug or similar.

<FIG> schematically illustrates an example of components of the node device 106b belonging to the second group 206b of node devices. The node device 106b may comprise the same components as the node device 106a, <NUM> as described above referring to <FIG>, except the at least one sensor device <NUM>. In other words, the node device 106b may comprise the processing unit <NUM> comprising one or more processors, the memory unit <NUM> comprising one or more memories, and a communication unit <NUM> comprising one or more communication devices, and possibly also the at least sensor device <NUM> for obtaining the elevator system related data as described above referring to <FIG>. The node device 106b may further comprise a power supply unit <NUM> comprising one or more batteries for powering the node device 106b.

Above the invention is defined referring to the monitoring system <NUM>. Next the at least some aspects of the invention are defined referring to <FIG> schematically illustrating an example of a method for monitoring an elevator system <NUM> with the elevator monitoring system <NUM>. <FIG> schematically illustrates the method as a flow chart.

At a step <NUM>, the second group 206b of node devices are in the sleep state and the elevator related monitoring data is relayed by the first group 206a of node devices, which are constantly on.

At a step <NUM>, the control node device <NUM> controls, i.e. commands, the second group of node devices 106b to turn on, i.e. wake up, on demand. At the step <NUM>, after the second group 206b of node devices are turned on, the elevator related monitoring data may be relayed by the first group 206a of node devices and by the second group 206b of node devices, which are able to relay the elevator related monitoring data only when the second group 206b of node devices are on. At least one of the plurality of node devices 106b belonging to the second group 206b of node devices relays elevator related monitoring data from at least one other node device 106b belonging to the second group 206b of node devices, when the second group 206b of node devices are on.

At a step <NUM>, the control node device <NUM> controls, i.e. commands, the second group of node devices 106b to enter the sleep state on demand. In other words, the operation (i.e. the turning on and entering the sleep state) of the second group 206b of node devices is command based operation controlled by the control node device <NUM>. The control node device <NUM> may send to the plurality of node devices 106b belonging to the second group 206b of node devices a message, e.g. a broadcast message, comprising a command, i.e. an instruction, to enter the sleep state and/or to turn on, i.e. wake up, after being in the sleep state. For example, the message may comprise a command for the plurality of node devices 106b belonging to the second group 206b of node devices to enter the sleep state during a certain period of time and to turn on after expiration of said certain period of time. The certain period of time may be defined by the control node device <NUM>. This command-based operation enables that all the plurality of node devices 106b belonging to the second group 206b of node devices wake up at the same time and that all the plurality of node devices 106b belonging to the second group 206b of node devices enter the sleep state at the same time. This enables that a synchronization of the is not needed.

The control node device <NUM> may control the on demand turning on and entering the sleep state of the second group 206b of the node devices according to one or more elevator system related parameters and/or one or more monitoring data related parameters as discussed above. The one or more elevator system related parameters may comprise one or more movement parameters representing movement of the elevator car. The one or more monitoring data related parameters may comprise need of a specific type of elevator related monitoring data, amount of data to be relayed, and/or need of battery status data of the plurality of node devices belonging to the second group 206b of node devices.

As discussed above, one or more of the plurality of node devices 106a belonging to the first group 206a of node devices and/or one or more of the plurality of node devices 106b belonging to the second group 206b of node devices may be associated with the at least one sensor device <NUM> obtaining the elevator related monitoring data to be relayed by the wireless mesh network <NUM> to the gateway device <NUM>. Alternatively or in addition, one or more of the plurality of node devices 106a belonging to the first group 206a of node devices and/or one or more of the plurality of node devices 106b belonging to the second group 206b of node devices may operate in the router role, in which the node device 106a, 106b participate relaying elevator related monitoring data send by another node device 106a, 106b, as also discussed above. Each node device 106a, 106b, either belonging to the first group 206a of node devices or to the second group 206b of node devices, being associated with the at least one sensor device <NUM> may be able to provide, e.g. send, the obtained elevator related monitoring data to be relayed via the wireless mesh network <NUM> at any time, when said node device 106a, 106b is on.

As discussed above, the wireless mesh network <NUM> relays, i.e. delivers or provides, the elevator related monitoring data from the one or more node devices 106a, 106b (belonging to the first group 206a of node devices and/or to the second group 206b of node devices) being associated with the at least one sensor device <NUM>, i.e. operating in the sensor role, to the gateway device <NUM>. As discussed above, the gateway device 205may then provide the elevator related monitoring data relayed via the wireless mesh network <NUM> to the at least one external unit <NUM>. The first group 206a of node devices are constantly on and able to participate to the relaying of the elevator related monitoring data. In other words, the first group 206a of node devices operate in an asynchronous mode, in which data may be delivered at any given time. The second group of 206b node devices are able to participate to the relaying of the elevator related monitoring data when the second group 206b of node devices are on. When the control node device <NUM> controls the second group of 206b node devices to turn on, the full wireless mesh network <NUM> operates in the asynchronous mode.

The above-described elevator monitoring system <NUM> and the monitoring method enables that data may be send and relayed via the wireless mesh network <NUM> at any given time, because at least part of the wireless mesh network <NUM>, i.e. the first group 206a of node devices, is constantly on. Alternatively or in addition, the above-described elevator monitoring system <NUM> and the monitoring method enables reducing power consumption of the battery-operated node devices 106b without decreasing reliability of the wireless mesh network <NUM>. This is because the battery-operated node devices 106b belonging to the second group 206b of node devices may be entered into the sleep mode to reduce power consumption, while the first group 206b of node devices are constantly on to enable that the reliability of the wireless mesh network <NUM> is not decreased.

Claim 1:
An elevator monitoring system (<NUM>) for monitoring an elevator system (<NUM>), wherein the elevator monitoring system (<NUM>) comprises a wireless mesh network (<NUM>) comprising:
a first group (206a) of node devices comprising a plurality of node devices (106a) configured to be constantly on and to be able to participate relaying elevator related monitoring data; and
a second group (206b) of node devices comprising a plurality of node devices (106b), at least one of the plurality of node devices (106b) belonging to the second group (206b) of node devices is configured to relay elevator related monitoring data from at least one other node device (106b) belonging to the second group (206b) of node devices, when the second group (206b) of node devices are on;
characterized in that the wireless mesh network further comprises a control node device (<NUM>) configured to control the second group (206b) of node devices to turn on and to enter a sleep state on demand.