Patent Description:
Conventional passenger conveyors, such as escalators and moving walkways, generally comprise a transportation band, on which passengers stand, which is propelled by a drive system to convey the passengers from one place to another place, for example between floors of a building or along extended distances.

The transportation band comprises a plurality of conveyance elements, such as steps or pallets, which are drivingly coupled to at least one drive member, such as a drive belt. The drive belt moves along a conveyance path, around a first turnaround portion, returns inside a balustrade (or associated support structure) following a return path and then around a second turnaround portion. A drive pulley, driven by a drive motor, is generally provided at one of the turnaround portions to drive the drive belt.

Escalators transport passengers between a lower landing region and an upper landing region. Escalators typically comprise an endless transportation band formed from a plurality of mutually connected step bodies. The transportation band is mounted on a drive belt or chain belt, which is driven about an upper reversal point at the upper landing region and a lower reversal point at the lower landing region. Moving walkways transport passengers between a first landing region and a second landing region. Moving walkways are typically pallet type moving walkways, which include a continuous series of pallets joined together to form a transportation band. Inclined moving walkways transport passengers over a vertical distance between a first/lower landing region and an upper/second landing region. Moving walkways can transport passengers over extended distances, and inclined sections can be provided within extended moving walkways.

Escalators and moving walkways are often provided with fault detection sensors which are configured to detect issues such as, but not limited to, friction, noise or component faults.

Condition Based Maintenance (CBM) is a form of predictive maintenance, in which sensor(s) are used to measure the operating conditions and/or status. Fault detection sensors produce data which can be collated and analysed to establish trends, predict failure, and calculate remaining operational life. It is known to use CBM techniques on escalators and moving walkways.

However, in all of these situations, it is difficult to accurately identify the location of a detected fault or issue.

<CIT> discloses a step with a diagnosing device. The diagnosing device has an acceleration sensor <NUM>, a microphone <NUM>, an information recording device <NUM> and a processing device <NUM>. The information recording device <NUM> records information from the acceleration sensor <NUM> and the microphone <NUM> as a vibration signal and a sound signal. The processing device <NUM> has a block specifying section <NUM> for specifying an approach block and a return block on the basis of the vibration signal, a statistic character quantity computing section <NUM> for obtaining a mean amplitude, sharpness and step cycle component of the vibration signal and the sound signal as the statistic character quantity on the basis of the information from the information recording device <NUM> and the block specifying section <NUM>, and a determining section <NUM> for determining existence of abnormality in an escalator by comparing the statistic character quantity with the preset character quantity.

<CIT> discloses a conveyor diagnostic device that diagnoses an abnormal state of a cyclically moving conveyor. The conveyor diagnostic device includes a first tilt sensor, a second tilt sensor, a table, and a processing unit. The first and second tilt sensors are attached to a predetermined position of the conveyor and detect tilt angles of the conveyor in a vertical direction and horizontal direction, respectively. The table indicates a relationship between a tilt angle which changes in the vertical direction and sections included in one revolution of the conveyor. The processing unit specifies an abnormality occurrence position of the conveyor based on a tilt angle in the vertical direction, the table, and an elapsed time after ingression for a section corresponding to the tilt angle in the vertical direction, when a tilt angle in the horizontal direction exceeds a predetermined management limit value.

<CIT> discloses an escalator control device that includes an inclination sensor <NUM> which is provided on a tread part of an escalator to output a signal according to the angle of posture within the circulation plane of the escalator, and a data processing unit <NUM> which determines the circulating position of the tread part having the inclination sensor <NUM> from the signal output from the inclination sensor <NUM>, stores the result of determination in a storage unit <NUM>, and counts the number of circulation of the escalator.

According to a first aspect of the present invention there is provided a monitoring system for a passenger conveyor according to claim <NUM>.

The term moveable components refers to the components of passenger conveyors which travel in a closed loop path, for example but not limited to, conveyance elements, such as escalator steps or pallets, drive members, such as drive belts, and moving handrails.

The determined fault may be one or more of the following: wear, bearing failure, dirt, lack of lubrication, misalignment of components. The or each fault detection sensor may be integral with or adjacent to an associated acceleration sensor.

The at least acceleration sensor and the associated fault detection sensor may be provided on any component of the passenger conveyor which follows a closed loop path during normal operation of the passenger conveyor. The passenger conveyor may include a plurality of conveyance elements, at least one moving handrail and a drive member. At least one acceleration sensor and its associated fault detection sensor may be provided on one or more of: a conveyance element, the drive member or the/each moving handrail.

The controller may be configured to determine the current location of the acceleration sensor in relation to a plurality of predefined regions of the closed loop path.

The controller may be configured to determine the plurality of predefined regions of the closed loop path based on the monitored gravity vector.

At least one acceleration sensor may act as the associated fault detection sensor.

The or each acceleration sensor may be configured to detect vibrations or misalignment of the moveable component on which it is mounted. For example, when abnormal vibrations are detected on the transportation band, this is generally an indication of issues or problems with the operation, such as, but not limited to, wear, bearing failure, dirt, lack of lubrication, or step/pallet misalignment; when abnormal vibrations are detected on the moving handrail, this can be an indication of issues or problems with the operation, such as, but not limited to, sticking, dirt, or loss of pressing force; and when abnormal vibrations are detected on the drive belt, this can be an indication of issues or problems with the operation, such as, but not limited to, wear, bearing failure, dirt, or lack of lubrication.

The fault detection sensor may be provided adjacent to the associated acceleration sensor. At least one fault detection sensor may be a microphone. At least one fault detection sensor may be configured to detect vibration. At least one fault detection sensor may be configured to detect alignment and/or misalignment of the transportation band. At least one fault detection sensor may be a temperature sensor. At least one fault detection sensor may be an electrical current sensor.

The controller is configured to monitor a start-up acceleration of the or each acceleration sensor. The controller is configured to determine the direction of travel of the or each acceleration sensor based on the monitored start-up acceleration and the monitored gravity vector.

The controller may be configured to determine an orientation of the or each acceleration sensor after power up of the acceleration sensor.

The controller may be provided as a discrete unit provided at or near the elevator system. The controller may comprise a controller unit incorporated into the or each acceleration sensor.

The monitoring system may comprise a control station located remotely from the passenger conveyor. The controller may further be configured to transmit data to the control station. The control station may be integrated into a hand held device, such as a smart phone, tablet or laptop. The controller may be configured for wireless communication with the control station. The control station may be configured to transmit data to a hand held device, such as a smart phone, tablet or laptop. The control station may utilise the transmitted data to predict maintenance and/or repair schedules. The control station may be configured to transmit the maintenance and/or repair schedules to a remote user. The control station may use the transmitted data for condition based maintenance. The control station may produce an output related to maintenance and/or repair. The control station output may be transmitted to an operator, located remotely from the control station.

According to a further aspect of the present invention, there is provided a passenger conveyor comprising a monitoring system as described above.

The passenger conveyor may be an escalator and the moveable component may be an escalator step.

The passenger conveyor may be an escalator. The passenger conveyor may be a moving walkway. The passenger conveyor may be an inclined moving walkway. The moveable component may be a conveyance element, such as an escalator step or a pallet. The moveable component may be a drive member, such as a drive belt. Acceleration sensors and associated fault detection sensors may be provided on one or more of: a conveyance element, a plurality of conveyance elements, the moving handrail(s), the drive member (drive belt).

According to a further aspect the present invention, there is provided a method of monitoring a passenger conveyor according to claim <NUM>.

The step of identifying a location of the detected fault may include determining the current location in relation to a plurality of predefined regions of the closed loop path.

The method may comprise a step of determining the plurality of predefined regions of the closed loop path based on the monitored gravity vector.

The step of receiving data indicative of a fault in the moveable component may include receiving data from the acceleration sensor.

The step of receiving data indicative of a fault in the moveable component may include receiving fault data from a fault detection sensor provided adjacent to the acceleration sensor.

The step of determining a direction of travel of the acceleration sensor includes: monitoring a start-up acceleration of the acceleration sensor; and determining the direction of travel based on the determined monitored start-up acceleration and the monitored gravity vector.

The method may comprise determining an orientation of the acceleration sensor after power up of the acceleration sensor.

The method may comprise transmitting data to a control station located remotely from the passenger conveyor.

The method may further comprise wired or wireless transmission of data to a remote location. The control station may use the transmitted data for condition based maintenance. The control station may produce an output related to maintenance and/or repair. The control station output may be transmitted to an operator, located remotely from the control station. The control station may transmit the maintenance and/or repair schedules to a remote device, such as a smart phone, tablet or laptop.

The system and method described are able to provide improved determination of the location of detected faults, which has clear advantages for operational monitoring and maintenance.

The monitoring system and monitoring method described can be used in Condition based Maintenance (CBM) processes to determine health level parameters of the passenger conveyor and predict maintenance and/or repair schedules. The monitoring system and monitoring method described can be used in conjunction with other known fault detection sensors provided on other components of the passenger conveyor.

Certain examples of the present invention will now be described with reference to the accompanying drawings in which:.

<FIG> shows a passenger conveyor <NUM>, represented in this figure as an escalator, on which passengers are transported between a first landing region <NUM> and a second landing region <NUM>. A truss <NUM> extends between the first landing region <NUM> (also referred to as a lower landing region) and the second landing region <NUM> (also referred to as an upper landing region). A central region <NUM>, which in this case is an inclined region <NUM>, extends between the first and second landing regions <NUM>, <NUM>.

Balustrades <NUM> which each support a moving handrail <NUM> extend along each side of the passenger conveyor <NUM>. The passenger conveyor <NUM> comprises a plurality of conveyance elements <NUM> (escalator steps <NUM>). The plurality of escalator steps <NUM> are mounted on a drive belt <NUM>.

A passenger conveyor monitoring system <NUM> includes an acceleration sensor <NUM> provided on one of the escalator steps <NUM> (conveyance elements <NUM>), a fault detection sensor <NUM> and a controller <NUM>. In this example, the acceleration sensor <NUM> acts as the fault detection sensor <NUM>. However, a separate fault detection sensor <NUM> could be provided adjacent to the acceleration sensor <NUM>. The sensors <NUM>, <NUM> are configured for wireless communication with the controller <NUM>.

The acceleration sensor <NUM> is a three axis accelerometer which is configured to measure the amount of acceleration due to gravity, from which the angle it is tilted with respect to a given reference can be determined. During the initial movement of the acceleration sensor <NUM>, there is an acceleration force due to the start-up motion of the escalator step <NUM> (conveyance element <NUM>). However, this is small in comparison to the measured acceleration due to gravity.

The controller <NUM> is configured for wireless communication with a control station <NUM>, located remotely from the passenger conveyor <NUM>. For example, the controller <NUM> can be configured to electrically communicate with a cloud computing network via a network interface device. The network interface device includes any communication device (e.g., a modem, wireless network adapter, etc.) that operates according to a network protocol (e.g., Wi-Fi, Ethernet, satellite, cable communications, etc.) which establishes a wired and/or wireless communication with a cloud computing network.

In passenger conveyors <NUM>, moveable components, such as conveyance elements <NUM> (escalator steps <NUM>), moving handrails <NUM> and drive belts <NUM>, move along defined closed loop paths P.

<FIG> shows a schematic representation of a closed loop path P of a moveable component of an inclined passenger conveyor <NUM>, in this case an escalator step <NUM> of an escalator <NUM> as shown in <FIG>. An acceleration sensor <NUM> is mounted on the escalator step <NUM>. The closed loop path P includes a conveyance path (upper portion) Pc, and a return path (lower portion) Pr. When the escalator <NUM> is in operation, the escalator step <NUM> and the acceleration sensor <NUM> move around the closed loop path P. <FIG> shows six regions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> defined in the closed loop path P. A first region <NUM> corresponds to the portion of the conveyance path Pc in which the escalator step <NUM> transports a passenger. A second region <NUM> is around an upper turning point TU. A third region <NUM> is in the upper landing area <NUM> of the return path Pr. A fourth region <NUM> is in the inclined region <NUM> of the return path Pr. A fifth region <NUM> is in the lower landing area <NUM> of the return path Pr; and a sixth region <NUM> is around a lower turning point TL.

In region <NUM>, the escalator step <NUM> moves horizontally and upwards, meaning that the acceleration sensor <NUM> is oriented with its "right side" upwards (shown with an arrow).

<FIG> shows the orientation of an escalator step <NUM> of <FIG> as it moves through region <NUM> of <FIG>. The escalator step <NUM> includes a passenger surface 26a on which a passenger stands which is substantially horizontal in this orientation (i.e. in region <NUM>). The acceleration sensor <NUM> is mounted on an underside 26b of the escalator step <NUM>. However, it will be appreciated that the acceleration sensor <NUM> can be mounted in any convenient location on the escalator step <NUM>. In this example, a separate fault detection sensor <NUM> is provided adjacent to the acceleration sensor <NUM>. The fault detection sensor <NUM> could be any sensor used within passenger conveyors for detecting faults, for example but not limited to, for detecting vibration; alignment and/or misalignment of the escalator step <NUM>; temperature, or electrical current. In region <NUM>, the escalator step <NUM> moves horizontally and upwards with the passenger surface 26a facing upwards, meaning that the acceleration sensor <NUM> is oriented with its "right side" upwards (shown with an arrow).

Referring back to <FIG>, as the escalator step <NUM> moves along the closed loop path P, its orientation changes. Since the acceleration sensor <NUM> is mounted to the escalator step <NUM> its orientation also changes. In other words, the acceleration sensor <NUM> tilts with respect to x, y and z axes, where the y axis is a vertical axis, and the x axis and z axis are horizontal axes.

Orientation of the acceleration sensor <NUM> in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, is schematically represented by references <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>. The acceleration due to gravity acting on the acceleration sensor <NUM>, referred to as a gravity vector V, can be monitored in the x, y and z axes.

<FIG> shows the acceleration due to gravity acting upon the acceleration sensor <NUM>, i.e. the gravity vector V, in each region of the closed loop path P of <FIG>. As the passenger conveyor <NUM> travels upwards, the acceleration sensor <NUM> moves in a clockwise direction around the closed loop path P, starting in region <NUM> and moving through regions <NUM>, <NUM>, <NUM>, <NUM>, <NUM> then back to <NUM>. As the acceleration sensor <NUM> moves along the closed loop path P and its orientation changes, the acceleration due to gravity acting on the acceleration sensor <NUM>, i.e. the gravity vector V (shown with dashed lines) varies in the x, y and z axes. The grey arrow shows the gravity vector V at the start of a region, and the variation of the gravity vector V within each region is represented with a dotted line.

In region <NUM>, the escalator step <NUM> moves horizontally and upwards with the passenger surface 26a facing upwards, meaning that the acceleration sensor <NUM>-<NUM> is oriented with its "right side" upwards, so it detects a negative gravitational acceleration in the y direction. In region <NUM>, the escalator step <NUM> moves around the upper turning point TU and the gravity vector V varies as the orientation of the acceleration sensor <NUM>-<NUM> changes. At a mid-point of region <NUM> (shown in <FIG>) the acceleration sensor <NUM>-<NUM> has rotated approximately ninety degrees. In region <NUM>, the escalator step <NUM> moves horizontally with the passenger surface 26a facing down, meaning that the acceleration sensor <NUM>-<NUM> is oriented upside down, so it detects a positive gravitational acceleration in the y axis. In region <NUM>, the escalator step <NUM> moves along the inclined portion of the return path Pr, and the acceleration sensor <NUM>-<NUM> remains upside down. In region <NUM>, the escalator step <NUM> moves horizontally again with the passenger surface 26a facing down and the acceleration sensor <NUM>-<NUM> upside down. In region <NUM>, the escalator step <NUM> moves around the lower turning point TL and the gravity vector V varies as the orientation of the acceleration sensor <NUM>-<NUM> changes.

<FIG> shows the acceleration due to gravity acting upon the acceleration sensor <NUM>, i.e. the gravity vector V, in each region of the closed loop path P of <FIG> as the passenger conveyor <NUM> moves downwards, The acceleration sensor <NUM> moves in an anti-clockwise direction around the closed loop path P, starting in region <NUM> and moving through regions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and then back to region <NUM>.

There is no differentiation in the gravity vector V in regions <NUM>, <NUM>, <NUM> & <NUM> between the upwards and downwards travel of the passenger conveyor (in motion) as well as stationary (no motion). Variation or progression of the gravity vector V as the acceleration sensor <NUM> moves through regions <NUM> and <NUM> is the only difference i.e. increasing or decreasing angle in XY plane.

When the passenger conveyor <NUM> is in normal operation, the moveable components including the escalator step <NUM> move at a constant speed in regions <NUM> and <NUM>. The acceleration sensor <NUM> can detect this from analysis of sensed vibrations. When the passenger conveyor <NUM> is not in motion, the acceleration due to gravity acting on the acceleration sensor <NUM>, i.e. the gravity vector V, in regions <NUM> and <NUM> is clearly identifiable and no vibrations are sensed by the acceleration sensor <NUM>.

With defined gravity vector V information for each region, the controller <NUM> can use the monitored gravity vector V of the acceleration sensor <NUM> to identify in which region(s) the acceleration sensor <NUM> located. For the example described above, this is outlined below:.

<FIG> shows an inclined passenger conveyor <NUM>, represented in this figure as an escalator, which moves passengers along an inclined region <NUM> between a first landing region <NUM> and a second landing region <NUM>. Balustrades <NUM> which each support a moving handrail <NUM> extend along each side of the passenger conveyor <NUM>. A passenger conveyor monitoring system <NUM> includes an acceleration sensor <NUM> provided on the moving handrail <NUM>, and a controller <NUM>. The acceleration sensor <NUM> is mounted to an underside of the moving handrail in a suitable location.

Only one moving hand rail <NUM> is shown in <FIG>. However, it will be appreciated that generally escalators <NUM> have two moving handrails <NUM> and an acceleration sensor <NUM> can be provided on each moving handrail <NUM>.

It will also be appreciated that the moving handrail <NUM> with a monitoring system <NUM> as shown on an escalator in <FIG>, could be also provided on an inclined moving walkway.

<FIG> shows a schematic representation of a closed loop path P of a moving handrail <NUM> of an inclined passenger conveyor <NUM>, such as the escalator <NUM> of <FIG>. In the closed loop path P of <FIG>, eight regions are defined <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Orientation of the acceleration sensor <NUM> in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is schematically represented by references <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>.

<FIG> shows the acceleration due to gravity acting upon the acceleration sensor <NUM>, i.e. gravity vector V (shown with a dashed line) in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the closed loop path P of <FIG>. As the passenger conveyor <NUM> travels upwards, and the acceleration sensor <NUM> mounted to the moving handrail <NUM> moves in a clockwise direction around the closed loop path P. As the orientation of the acceleration sensor <NUM> varies, the acceleration due to gravity acting on the acceleration sensor <NUM>, i.e. the gravity vector V (dashed lines) varies in the x, y and z axes. Variation of the gravity vector V within each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is represented with a dotted line.

In regions <NUM>, <NUM> and <NUM>, the moving handrail <NUM> is following a conveyance path Pc and its upper surface is facing upwards providing support for passengers, and the acceleration sensor <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> has its right side upwards so it detects a negative gravitational acceleration in the y direction. In regions <NUM> and <NUM>, the moving handrail <NUM> moves around the upper turning point TU and the lower turning point TL and the gravity vector V changes with the changing orientation of the acceleration sensor <NUM>-<NUM>, <NUM>-<NUM>. In regions <NUM>, <NUM> and <NUM> the moving handrail <NUM> is moving along its return path Pr. In region <NUM>, the acceleration sensor <NUM>-<NUM> initially moves upside down and is then tilted as it moves up an inclined section to a turning point TM. In region <NUM>, the acceleration sensor <NUM>-<NUM> is tilted as it moves down the inclined portion of the return path Pr. In region <NUM>, the acceleration sensor <NUM>-<NUM> is upside down.

<FIG> shows a passenger conveyor <NUM>, represented in this figure as moving walkway on which passengers are transported along a horizontal central region <NUM> between a first landing region <NUM> and a second landing region <NUM>. The passenger conveyor <NUM> comprises a continuous series of escalator steps <NUM> in the form of pallets <NUM>. Balustrades <NUM> which each support a moving handrail <NUM> extend along each side of the passenger conveyor <NUM>. A passenger conveyor monitoring system <NUM> includes an acceleration sensor <NUM> provided on one of the escalator step <NUM>, and a controller <NUM>. The acceleration sensor <NUM> acts as a fault detection sensor <NUM>.

<FIG> shows a schematic representation of a closed loop path P of <FIG>. In the closed loop path P of <FIG>, eight regions are defined <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Orientation of the acceleration sensor <NUM> in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is schematically represented by references <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>.

<FIG> shows acceleration due to gravity acting upon the acceleration sensor <NUM>, i.e. the gravity vector V, in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the closed loop path P of <FIG>. As the passenger conveyor <NUM> travels from left to right, the acceleration sensor <NUM>, mounted to a escalator step <NUM>, moves in a clockwise direction around the closed loop path P, starting in region <NUM> and moving through regions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and then back to region <NUM>. As the acceleration sensor <NUM> moves along the closed loop path P, its orientation varies, the acceleration due to gravity acting on the acceleration sensor <NUM>, i.e. the gravity vector V (dashed lines) varies in the x, y and z axes. Variation of the gravity vector V within each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is represented with a dotted line.

In region <NUM>, the escalator steps <NUM> are following a conveyance path Pc, its upper surface is facing upwards providing support for passengers, and the acceleration sensor <NUM>-<NUM> has its right side upwards so it detects a negative gravitational acceleration in the y direction. In regions <NUM> and <NUM>, the moving handrail <NUM> moves around a first turning point TU and a second turning point TL and the gravity vector V changes with the changing orientation of the acceleration sensor <NUM>. At a mid-point in regions <NUM> and <NUM> (represented in <FIG>), the acceleration sensor <NUM>-<NUM>, <NUM>-<NUM> is rotated approximately ninety degrees.

In regions <NUM>, <NUM> and <NUM> the moving handrail <NUM> is moving along its return path Pr and the acceleration sensor <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> is upside down. The previously determined region can be used to distinguish between regions <NUM>, <NUM> and <NUM>. Regions <NUM> and <NUM> can be identified due to the inclined travel of the acceleration sensor <NUM>-<NUM>, <NUM>-<NUM>.

<FIG> shows a schematic representation of an exemplary method of monitoring a passenger conveyor <NUM> with the monitoring system <NUM>. The acceleration sensor <NUM> is mounted to a moveable component <NUM>, <NUM>, <NUM> of a passenger conveyor <NUM> as outlined above.

In step <NUM>, the controller <NUM> determines the orientation of the acceleration sensor <NUM>. The initial orientation of the acceleration sensor <NUM> is defined in order to interpret the data collected.

In step <NUM>, the controller <NUM> determines a direction of travel of the acceleration sensor <NUM>.

In step <NUM> the controller <NUM> determines a location region of the acceleration sensor <NUM>.

The controller <NUM> monitors the location of the acceleration sensor <NUM> and when data is received which indicates a fault (step <NUM>), the controller <NUM> determines in which region the indicated fault is located (step <NUM>).

The fault data could be generated by the acceleration sensor <NUM> or by another fault detection sensor <NUM> located adjacent to the acceleration sensor <NUM>.

The controller <NUM> can be configured to define the regions of the closed loop path P when an acceleration sensor <NUM> has been installed on a movable component <NUM>, <NUM>, <NUM> in a passenger conveyor <NUM>. During the set-up process, the controller <NUM> monitors data relating to the gravity vector V and a start-up acceleration A. The controller <NUM> analyses the monitored data to establish patterns in order to define the different regions in the closed loop path P. Once the set-up is complete, the controller <NUM> monitors the current location in order to determine in which region the acceleration sensor <NUM> is located. The set-up process could be carried out in step <NUM> of the process described in <FIG>.

The method steps of <FIG> are explained in more detail below.

The determination of the orientation of the acceleration sensor <NUM> can be achieved manually when the acceleration sensor <NUM> is installed in the passenger conveyor <NUM>. For example, the acceleration sensor <NUM> could include markings to indicate the correct orientation to the maintenance engineer.

Alternatively, or additionally (i.e. as a system check), the monitoring system <NUM> can follow a self-orientation determination process.

<FIG> is a schematic representation of an exemplary orientation determination process <NUM> of the method of <FIG>. The process <NUM> of <FIG> describes how the orientation of an acceleration sensor <NUM> moving in the closed loop path P shown in <FIG> can be determined. However, it will be appreciated that a self-orientation process can be defined for any closed loop path P.

First a check is made as to whether the acceleration sensor <NUM> is powered up. If the acceleration sensor is not powered up, then no action is required by the controller <NUM>.

In step <NUM>, the controller <NUM> determines whether the acceleration sensor <NUM> is mounted on the escalator step <NUM>. This could be a manual operation carried out by the maintenance engineer. Alternatively or additionally (for example as a system check), data from the acceleration sensor <NUM> can be used to determine whether it is mounted. After power-up, the acceleration sensor <NUM> is determined not to be mounted if the detected motion is not consistent with recognised passenger conveyor <NUM> movement, meaning that the acceleration sensor <NUM> is probably being manually handled, for example if there is a significant gravity vector V in the z axis for longer than <NUM> msec, or it is in storage. It can be determined that the acceleration sensor <NUM> is mounted if the detected motion is consistent with recognised passenger conveyor <NUM> movement, for example if the gravity vector V is stationary for more than <NUM> seconds, then rotates in the same direction of the XY plane through a complete <NUM> degrees over a time period of greater than <NUM> seconds.

In step <NUM>, the controller <NUM> determines whether the acceleration sensor <NUM> is in region <NUM>. The acceleration sensor <NUM> is located in region <NUM> if the gravity vector V is in the positive y direction (upside down) with an x offset of more than <NUM> degrees (either positive or negative).

In step <NUM>, the controller <NUM> analyses the gravity vector V component in the x-axis and sets the orientation accordingly in steps <NUM> and <NUM>. In step <NUM>, this is stored in the controller <NUM> until the acceleration sensor <NUM> is next powered up.

The determination of the direction of travel of the acceleration sensor <NUM> is achieved by the controller <NUM> monitoring both the gravity vector V and a start-up acceleration A of the acceleration sensor <NUM>. This can be determined for any closed loop path P.

An example related to <FIG> is explained below.

Figure 14a shows the variation of acceleration due to gravity acting upon the acceleration sensor <NUM>, i.e. the gravity vector V (dashed line) as the passenger conveyor <NUM> of <FIG> moves upwards, and the acceleration sensor <NUM> moves in an clockwise direction around the closed loop path P. The start-up acceleration A in each region <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is represented with an arrow depicted on the gravity vector V.

Figure 14b shows the variation of the gravity vector V and the start-up acceleration A as the passenger conveyor <NUM> of <FIG> moves downwards, and the acceleration sensor <NUM> moves in an anti-clockwise direction around the closed loop path P.

<FIG> is a schematic representation of an exemplary process <NUM> for determining the direction of travel of the acceleration sensor <NUM> in the method of <FIG>. The process <NUM> of <FIG> describes how the direction of travel of the acceleration sensor <NUM> moving in the closed loop path P shown in <FIG> can be determined. However, it will be appreciated that a process can be defined for any closed loop path P.

In step <NUM>, the controller <NUM> determines whether the passenger conveyor <NUM> is in motion. This can be done by detecting recognised passenger conveyor <NUM> movement, for example it can be determined that the acceleration sensor <NUM> is in motion if there are vibrations greater than <NUM> milli-Gs in at least <NUM> axes.

If the acceleration sensor <NUM> is not in motion the controller <NUM> determines whether the acceleration sensor <NUM> is in regions <NUM>, <NUM>, or <NUM> (step <NUM>). This determination is made by comparing the current gravity vector V to the known gravity vectors for each region. The acceleration sensor <NUM> is located in region <NUM> if the gravity vector V is in the negative Y direction (right-side up) with an X offset of less than <NUM> degrees (either positive or negative). The acceleration sensor <NUM> is located in either region <NUM> or region <NUM> if the gravity vector V is in the positive Y direction (upside down) with an X offset of less than <NUM> degrees (either positive or negative).

In step <NUM>, if the acceleration sensor is not in region <NUM>, <NUM> or <NUM>, the controller continues to monitor for motion (step <NUM>).

If the acceleration sensor is in region <NUM>, <NUM> or <NUM>, the controller <NUM> continues to monitor for motion (step <NUM>) and once the acceleration sensor <NUM> starts to move, a determination of direction of travel can be made based on the orientation of the acceleration sensor <NUM> and whether the change in start-up acceleration A in the x direction is positive or negative (step <NUM>).

In step <NUM>, if the acceleration sensor <NUM> is in motion the controller <NUM> checks whether the direction is already known (step <NUM>). If not, the controller <NUM> determines whether the acceleration sensor <NUM> is in regions <NUM>, <NUM>, or <NUM> (step <NUM>) as outlined above. If the acceleration sensor <NUM> is in region <NUM>, <NUM> or <NUM>, the controller <NUM> determines a direction of travel based on the orientation of the acceleration sensor <NUM>, the current direction of the gravity vector V and the previous direction of the gravity vector V (step <NUM>).

If the acceleration sensor <NUM> is not in regions <NUM>, <NUM> or <NUM> the controller <NUM> determines whether the acceleration sensor <NUM> is in region <NUM> or <NUM> (step <NUM>). The mid-point of regions <NUM> and <NUM> can be identified as the gravity vector is in the positive or negative X direction. If yes, the controller <NUM> determines a direction of travel based on the orientation of the acceleration sensor <NUM> and whether the start-up acceleration A in the x direction is positive or negative (step <NUM>).

If the acceleration sensor <NUM> is not in regions <NUM> or <NUM>, the controller <NUM> checks again whether the acceleration sensor <NUM> is in regions <NUM>, <NUM> or <NUM> (step <NUM>).

Once the direction of travel is established, the determination of a current location region of the acceleration sensor <NUM> is achieved by the controller <NUM> monitoring the gravity vector V taking into account the direction of travel. This can be determined for any closed loop path P.

The controller <NUM> monitors the location of the acceleration sensor <NUM> and when data is received which indicates a fault, the controller <NUM> can determine in which region the indicated fault is located. The fault data could be generated by the acceleration sensor <NUM> or by another fault detection sensor located adjacent to the acceleration sensor <NUM>.

<FIG> is a schematic representation of an exemplary process <NUM> for determining the location of the acceleration sensor <NUM> in the method of <FIG>. The process <NUM> of <FIG> describes how the direction of travel of the acceleration sensor <NUM> moving in the closed loop path P shown in <FIG> can be determined. However, it will be appreciated that a process can be defined for any closed loop path P.

In step <NUM>, the controller <NUM> determines whether the gravity vector V is entirely in the y-axis, and if yes in step <NUM> the controller <NUM> checks the direction of the gravity vector V. When the gravity vector V is negative in the y-axis, the controller <NUM> determines that the acceleration sensor <NUM> is in region <NUM> (step <NUM>).

If the determination from step <NUM> is no, the controller <NUM> checks the determined direction of travel (step <NUM>). If the direction is up, the controller <NUM> checks the previous location region to determine whether the current location region is <NUM> or <NUM> (step <NUM>). If the direction is down, the controller <NUM> checks the previous location region to determine whether the current location region is <NUM> or <NUM> (step <NUM>).

If the determination in step <NUM> is no, then the controller <NUM> determines whether the gravity vector V is entirely in the x-axis (step <NUM>). If yes, in step <NUM> the controller <NUM> checks the direction of the gravity vector V. If the gravity vector is negative in the x-axis, the controller <NUM> checks the orientation to determine whether the current location is in region <NUM> or <NUM> (step <NUM>). If the gravity vector V is positive in the x-axis, the controller <NUM> checks the orientation to determine whether the current location is in region <NUM> or <NUM> (step <NUM>). If the orientation of the acceleration sensor <NUM> is known, then it is be possible to determine whether the current location is <NUM> or <NUM> based on the direction of the gravity vector V, i.e. in region <NUM> it will be in the positive x direction.

If the determination in step <NUM> is no, the controller <NUM> determines if the gravity vector V is mostly in the positive y axis but also in the x direction (step <NUM>). If yes, the controller <NUM> determines that the location is in region <NUM> (step <NUM>). If no, then the controller <NUM> repeats step <NUM>.

Whilst the examples described above relate to specific components of passenger conveyors, it will be appreciated that the monitoring system <NUM> and monitoring method <NUM> described can be used on any component in a passenger conveyor <NUM> which moves in a defined closed loop path P.

Claim 1:
A monitoring system (<NUM>) for a passenger conveyor (<NUM>) comprising at least one acceleration sensor (<NUM>) provided on a movable component (<NUM>, <NUM>, <NUM>) of the passenger conveyor (<NUM>), wherein the moveable component (<NUM>, <NUM>, <NUM>) moves in a closed loop path (P) when the passenger conveyor (<NUM>) is in use; a fault detection sensor (<NUM>) associated with the or each acceleration sensor (<NUM>) and configured to provide data indicative of a fault in the moveable component (<NUM>, <NUM>, <NUM>); and a controller (<NUM>) configured to:
receive data from the or each acceleration sensor (<NUM>);
monitor a gravity vector (V) of the or each acceleration sensor (<NUM>);
determine a direction of travel of the or each acceleration sensor (<NUM>);
determine a current location of the or each acceleration sensor (<NUM>) based
on the monitored gravity vector (V) and the determined direction of travel;
detect a fault from the data received from the or each fault detection sensor (<NUM>);
identify a location of the detected fault based on the determined current location of the associated acceleration sensor (<NUM>);
characterised in that the controller (<NUM>) is further configured to
monitor a start-up acceleration (A) of the or each acceleration sensor (<NUM>)
and determine the direction of travel of the or each acceleration sensor (<NUM>) based on the monitored start-up acceleration (A) and the monitored gravity vector (V).