Patent Description:
Escalators are widely used in a variety of occasions, including shopping centers, office buildings, public facilities, and in other indoor or outdoor environments. Its safe and steady operation requires monitoring operating conditions of relevant parts, and those operating conditions depend heavily on the occasion in which the escalator is running, the temperature, humidity, the amount of dust surrounding it, as well as the passenger traffic thereon and the frequency of use. Thus, every escalator is in different condition and need frequent onsite inspection and maintenance of those relevant parts for proper operation. This involves a great deal of work and makes it difficult for escalator manufactures and users to keep track of its operating condition in an organized fashion. Previously known solutions for monitoring operating conditions of escalators are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, for instance.

To solve this issue, an escalator monitoring system needs to be improved in such a way that it allows remote monitoring and produces raw data in connection with the parts relevant to steady operation of the escalator. In addition, the system can process and analyze the raw data, promptly determine the operating condition of the escalator, warn of and preempt a possible failure independent of human interference, and provide to the manufacturer and the user of the escalator, data generated during its operation for reference.

A purpose of the present invention is to provide an escalator monitoring system as defined in claim <NUM> that meets the needs described above, and an escalator monitoring method as defined in claim <NUM>. Particular embodiments of the escalator monitoring system are disclosed in claims <NUM> to <NUM> and particular embodiments of the escalator monitoring method are disclosed in claims <NUM> to <NUM>.

The escalator monitoring system of the present invention prevents failure of an escalator and provides predictive maintenance thereto, and thus reduces labor and cost associated with the maintenance of the escalator, through a data collection device. Located at or near the parts of the escalator in connection with its safety and normal operating condition, the data collection device collects data while the escalator is running, analyzes, predicts, and determines the operating condition of the escalator, and responses to the determined operating condition.

Passenger traffic impacts the normal operation of the escalator. High passenger traffic beyond the capacity of the escalator can cause a safety issue. And the passenger traffic can be evaluated based on the motor power of the escalator. Thus, the motor power can be used to analyze, predict, and determine the operating condition of the escalator, and thus to provide predictive maintenance.

The present invention is further described in detail in the embodiments below.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the first embodiment.

In the not claimed embodiment, the escalator monitoring device monitors the lubrication condition of an escalator. It uses a data collection device to collect data about the sound generated by the metal parts, to analyze the sound data, and to determine whether the lubrication condition is normal The data collection device is generally a digital microphone module. It is positioned near contact position between a drive and a drive chain, contact position between the drive chain sprocket and the drive chain of an escalator, or contact position between the skirt panel and the step guide pad under the step front cover, or, if need be, at the position on the truss of an escalator near the contact position between the drive chain and the motor, or any position near parts that are in contact and thus require monitoring. The microphone module may use ordinary microphones commonly used in a cellphone, or ultrasonic microphones. It can record sound waves and support playback function. The digital microphone module continuously collects sound data and saves sound documents, which documents can replay as needed.

In <FIG>, sound data collection device <NUM> collects sound data at a contact position between a drive and a drive chain, at a contact position between the drive chain sprocket and the drive chain of the gearbox of an escalator, or at a contact position between the skirt panel and the step guide pad under the step front cover. A sound document containing the sound data is saved at local data processing device <NUM> of local device <NUM>, and processed through band-pass filter <NUM>. The document is then sent via sound data transmittal device <NUM> to cloud processor <NUM>.

At the band-pass filter <NUM>, the sound data is denoised so that sound data within certain frequency range [FL to FH] is obtained. Usually, FL is about <NUM>-<NUM>, and FH is above <NUM>, because sound data within that range is highly likely relevant to noises produced by friction between metals. This process can be done with Spectrogram function spectrograph.

<FIG> is a Spectrogram function spectrograph that exemplarily illustrates the process of denoising low-frequency and high frequency noises with the band-pass filter. <FIG> shows sound signals generated by contact between a normal chain without rust and a chain sprocket, which mainly focus on low-frequency range. <FIG> shows sound signals generated by contact between a rusty chain and a chain sprocket, which mainly are a mix of low-frequency noises and high-frequency peaks. <FIG> shows a sound pattern separated after applying the band-pass filter with frequency range of [<NUM>, <NUM>] and retaining only those relevant to the extent of rust existed on the chain.

The next step is to calculate Key Performance Index (KPI) of the filtered sound data. The KPI relevant to the noise generated by contact between metal components may be root-mean-square (RMS) value of the sound data. In this embodiment, a RMS value is used to calculate the peak value of the filtered sound data.

The RMS value is sent to the cloud processor <NUM> via the sound data transmittal device <NUM>. At the cloud processor <NUM>, a comparison is made between the RMS value a predetermined threshold value. If the RMS is higher, the cloud processor responses by sending alarm signals to customer service center, or by direct communicating with maintenance personnel to conduct lubrication maintenance. The comparison is exemplarily illustrated in <FIG>.

The predetermined threshold value may be obtained by testing under various lubrication conditions, or by other kinds of experiments.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the second embodiment.

In the second not claimed embodiment, data collection device <NUM> collects sound data at the contact position between the drive and the drive chain, at the contact position between the drive chain sprocket and the drive chain of the gearbox of an escalator, or at the contact position between the skirt panel and the step guide pad under the step front cover. A sound document containing the sound data is saved at local data processing device <NUM> of local device <NUM>. The local data processing device <NUM> calculates the special feature value of the sound data, which is then sent via sound data transmittal device <NUM> to cloud processor <NUM>.

<FIG> shows comparisons between sound data of different failure types. <FIG> shows a sound data pattern produced when step misalignment occurs, <FIG> shows that produced by rusty drive chains, and <FIG> shows a sound data pattern when an escalator is in normal operating condition. Apparently, different types of failure sound data have different patterns and, thus, different special feature values.

In this not claimed embodiment, the local data processing device <NUM> calculates the special feature value of sound data. The special feature value may be zero crossing rate, energy, entropy of energy, spectral centroid, spectral spread, spectral entropy, spectral flux, spectral rolloff, MFCC, chroma vector or chroma deviation.

The calculated special feature value then is sent to the cloud processor <NUM> via the data transmittal device <NUM>. At the cloud processor <NUM>, classifier <NUM> is trained with history or saved sound data of different failure types. The classifier <NUM> employs neural network algorithm and adjusts special feature vectors to better represent special feature values of different failure types.

<FIG> is an illustration of the analysis flow of the classifier <NUM>. The classifier <NUM> sends the calculated special feature values it received to three neurons. Each neuron analyzes and calculates for each type of failure and outputs predicted confidence interval for each type of failure and result based on the confidence interval, the result indicating whether the type of failure is going to happen.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the not claimed third embodiment.

In the not claimed third embodiment, data collection device <NUM> collects sound data at the contact position between the drive and the drive chain of an escalator, at the contact position between the drive chain sprocket and the drive chain of an escalator, or at the contact position between the skirt panel and the step guide pad under the step front cover. A sound document containing the sound data is sent via sound data transmittal device <NUM> to cloud processor <NUM>. At the cloud processor <NUM>, the sound data is denoised by bass-pass filter <NUM> so that sound data within certain frequency range [FL to FH] is obtained. Usually, FL is about <NUM>-<NUM>, and FH is above <NUM>. Then the cloud processor <NUM> calculates Key Performance Index (KPI) of the filtered sound data. The KPI relevant to the noise generated by contact between metal components may be root-mean-square (RMS) value of the sound data. In this embodiment, a RMS value is used to calculate the peak value of the filtered sound data. The cloud processor <NUM> then compares the RMS value against a predetermined threshold value. If the RMS is higher, the cloud processor responses by sending alarm signals to customer service center, or by direct communicating with maintenance personnel to conduct lubrication maintenance. The comparison is exemplarily illustrated in <FIG>. The predetermined threshold value may be obtained by testing under various lubrication conditions, or by other kinds of experiments.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the not claimed fourth embodiment.

In the not claimed fourth embodiment, data collection device <NUM> is a sound date collection device, which collects sound data at the contact position between the drive and the drive chain, at the contact position between the drive chain sprocket and the drive chain of the gearbox of an escalator, or at the contact position between the skirt panel and the step guide pad under the step front cover. A sound document containing the sound data is sent via sound data transmittal device <NUM> to cloud processor <NUM>. At the cloud processor <NUM>, special features value of the sound data is calculated. Classifier <NUM> is trained with history or saved sound data of different failure types. The classifier <NUM> employs neural network algorithm and adjusts special feature vectors to better represent special feature values of different failure types.

In this not claimed embodiment, the cloud processor <NUM> calculates the special feature values of sound data of different types. The special feature value may be zero crossing rate, energy, entropy of energy, spectral centroid, spectral spread, spectral entropy, spectral flux, spectral rolloff, MFCC, chroma vector or chroma deviation.

<FIG> is an illustration of the analysis flow of the classifier <NUM>. The classifier <NUM> sends the calculated special feature values it received to three neurons. Each neuron analyzes and calculates for each type of failure and outputs predicted confidence interval for each type of failure and result based on the confidence interval.

The not claimed third and fourth embodiments differ mainly from the not-claimed first and second embodiments in that data processing at the local device <NUM> in the not claimed first and second embodiments takes place at the cloud processor <NUM> in the third and fourth embodiments. Nonetheless, this may increase cost associated with data transmittal from the local device <NUM> to the cloud processor <NUM>.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the not claimed fifth embodiment.

In the not claimed fifth embodiment, sound data collection device <NUM> collects sound data at the contact position between the drive and the drive chain, at the contact position between the drive chain sprocket and the drive chain of the gearbox of an escalator, or at the contact position between the skirt panel and the step guide pad under the step front cover. A sound document containing the sound data is denoised by band-pass filter <NUM>, so that sound data within certain frequency range [FL to FH] is obtained. Usually, FL is about <NUM>-<NUM>, and FH is above <NUM>. Then local data processing device <NUM> calculates Key Performance Index (KPI) of the filtered sound data. The KPI relevant to the noise generated by contact between metal components may be root-mean-square (RMS) value of the sound data. In this embodiment, a RMS value is used to calculate the peak value of the filtered sound data. In this embodiment, the local data processing device <NUM> further compares the RMS value against a predetermined threshold value. The comparison process is exemplarily illustrated in <FIG>. If the RMS is higher, the local data processing device <NUM> sends response <NUM>, the response <NUM> may be alarm signals. The alarm signals are sent to customer service center, or directly communicated with maintenance personnel to conduct lubrication maintenance. The local data processing device <NUM> may also send the RMS value to a cloud processor only. The predetermined threshold value may be obtained by testing under various lubrication conditions, or by other kinds of experiments.

<FIG> is a flow chart with respect to the escalator monitoring system in accordance with the not claimed sixth embodiment.

In the not claimed sixth embodiment, sound data collection device <NUM> collects sound data at the contact position between the drive and the drive chain, at the contact position between the drive chain sprocket and the drive chain of the gearbox of an escalator, or at the contact position between the skirt panel and the step guide pad under the step front cover. Local data processing device <NUM> at local <NUM> directly calculates special feature value of the sound data. Classifier <NUM> is then trained with history or saved sound data of different failure types. The classifier <NUM> employs neural network algorithm and adjusts special feature vectors to better represent special feature values of different failure types. In this embodiment, the special feature value may be zero crossing rate, energy, entropy of energy, spectral centroid, spectral spread, spectral entropy, spectral flux, spectral rolloff, MFCC, chroma vector or chroma deviation.

<FIG> shows comparisons between sound data of different failure types. <FIG> shows a sound data pattern produced when step misalignment occurs, <FIG> shows a sound data pattern produced by rusty drive chains, and <FIG> shows a sound data pattern when an escalator is in normal operating condition. Apparently, different types of failure sound data have different patterns and, thus, different special feature values.

<FIG> is an illustration of the analysis flow of the classifier <NUM>. The classifier <NUM> sends the calculated special feature values it received to three neurons. Each neuron analyzes and calculates for each type of failure and outputs predicted confidence interval for each type of failure and result based on the confidence interval. The local data processing device may respond to the result. The response may be alarm signals. The alarm signals may be sent to customer service center, or be directly communicated with maintenance personnel to conduct lubrication maintenance. It is also possible to send the result directly to a cloud processor.

An escalator monitoring system can collect data of an escalator and analyze it in any environment, either indoor or outdoor or quiet or noisy, independent of subjective human judgment. It also predicts possible failure without the need to stop the operation of the escalator, saves maintenance time and reduces associated cost, improving its safety and ride comfort.

<FIG> is the not claimed first embodiment of sound data collection device <NUM> of an escalator monitoring system used in the various embodiments. In thi not claimed embodiment, the sound data collecting device <NUM> comprises a sensor circuit box <NUM>. The sensor circuit box <NUM> comprises a top wall <NUM>, a bottom wall <NUM>, and side walls <NUM>. A sound picking hole <NUM> is disposed in the top wall <NUM>, the hole <NUM> being a through hole. The sound data collection device <NUM> further comprises a sound sensor <NUM> disposed within the cavity. The sound sensor <NUM> rests over the bottom wall <NUM> of the sensor circuit box by means of support <NUM>. A water-resistant membrane <NUM> is arranged at the opening of the sound picking hole facing the cavity and above the sound sensor <NUM>. The water-resistant membrane prevents water or humidity from entering into the sound data collection device <NUM>, and possesses good sound transmission capability.

<FIG> is a not claimed second embodiment of sound data collection device <NUM> of an escalator monitoring system used in the various embodiments. It differs from the first embodiment in that the sound sensor <NUM> directly attaches to the top wall <NUM> of the sensor circuit box <NUM> at a position below the sound picking hole <NUM> and the water-resistant membrane <NUM><NUM>.

<FIG> is a not claimed third embodiment of sound data collection device <NUM> of an escalator monitoring system used in the various embodiments. It differs from the first embodiment in that the sound data collection device <NUM> is configured as a double-side-used sound data collection device. Its sensor circuit box <NUM> has two through-hole type sound picking holes <NUM> and <NUM> in the top <NUM> and the bottom <NUM>, respectively, and two sound sensors <NUM> and <NUM>. The sound sensors rest over the top wall <NUM> and the bottom wall <NUM> by means of supports <NUM> and <NUM>, respectively. Each sound picking hole <NUM>, <NUM> has a water-resistant membrane <NUM>, <NUM> attached thereto at the opening facing the cavity.

<FIG> is the not claimed fourth embodiment of sound data collection device <NUM> of an escalator monitoring system used in the various embodiments. It differs from the second embodiment in that the sound data collection device <NUM> is configured as a double-side-used sound data collection device. Its sensor circuit box <NUM> has two through-hole type sound picking holes <NUM> and <NUM> in the top wall <NUM> and the bottom wall <NUM>, respectively, and two sound sensors <NUM> and <NUM>. Each sound sensor directly attaches to the top wall <NUM> and the bottom wall <NUM>. Each sound picking hole <NUM>, <NUM> has a water-resistant membrane <NUM>, <NUM> attached thereto at the opening facing the cavity. Each water-resistant membrane <NUM>, <NUM> is located between the opening of the sound picking hole <NUM>, <NUM> facing the cavity and the sound sensor that is attached to the corresponding opening.

With reference to <FIG>, a flow chart of the not claimed sixth embodiment with respect to an escalator monitoring system is explained in detail. This embodiment relates to monitoring of temperature of a handrail of an escalator.

<FIG> illustrates the block diagram of the escalator monitoring system. The monitoring system <NUM> comprises temperature sensor assembly <NUM>, data transmittal unit <NUM>, and a server <NUM>. The temperature sensor assembly <NUM> is used to detect ambient temperature and the temperature of the handrail of an escalator when it is turned off, in idling condition, or in full operating condition. A back surface of the handrail is the surface which directly contact in friction with metal of a friction wheel, a bearing and a guide wheel or guide block of the handrail and a curve section. For example, the temperature sensor assembly <NUM> includes a handrail temperature sensor used to detect the temperature of the back surface of the handrail and an ambient temperature sensor used to detect the ambient temperature. In general, when the escalator is turned off, the ambient temperature is the same as the temperature of the handrail. Thus, the technical personnel who need to know the operating condition of an escalator concern more about the temperature of the back surface of the handrail and the ambient temperature when the escalator runs in idling and full operating conditions. In this embodiment, the temperature sensor assembly <NUM> detects the ambient temperature and the temperature of the back surface of the handrail when the escalator is in full operating condition. The processor <NUM> collects the ambient temperature and the temperature of the back surface of the handrail detected by the temperature sensor assembly, either in wireless manner (e.g., radio frequency, Bluetooth, zigbee) or in wired manner, and transmits the ambient temperature and the temperature of the back surface of the handrail to the server <NUM> at a predetermined frequency (for example, once per one minute).

The server <NUM> compares the ambient temperature with the handrail back surface and obtains a temperature difference between the ambient temperature and the handrail back surface, and a predetermined temperature difference threshold is stored in the server, and if the temperature difference between the ambient temperature and the handrail back surface temperature exceeds the predetermined temperature difference threshold, the server will send an alarm signal.

Specifically, the server collects the ambient temperatures and the temperatures of the back surface of the handrail detected by the temperature sensor assembly <NUM> during a pre-determined period of time t1, and compares the ambient temperatures and the temperatures of the handrail, to obtain a first average value M<NUM> and a first variance σ<NUM> of the temperature differences of the ambient temperatures and the temperatures of the back surface of the handrail in the pre-determined period. In addition, the server captures the temperature of the back surface of the handrail and the ambient temperature detected by the temperature sensor assembly in another predetermined period t<NUM> and compare the ambient temperature and the handrail back surface temperature, obtains a second mean value M<NUM> and a second variance σ<NUM> of the temperature difference between the ambient temperature and the temperature of the back surface of the handrail in this another predetermined period.

In the next, the server compares the first mean value and the second mean value, and sends a first alarm signal when a difference between the second mean value and the first mean value is k times greater than the first variance (M<NUM>>M<NUM>+kσ<NUM>), wherein k, set in the server, is an integer greater than <NUM>.

Furthermore, the server determines relation between the first variance σ<NUM> and a predetermined first threshold T<NUM> and the relation between the second variance σ<NUM> and a predetermined second threshold T<NUM> and if the first variance is smaller than the first threshold and the second variance is smaller than the second threshold, that is, σ<NUM>< T<NUM><IMG> σ<NUM><T<NUM>, the local data processing device or the cloud processor will send a second alarm signal. Comparing with the first alarm signal, the second alarm signal is more accurate.

<FIG> illustrate an escalator in frictional-wheel handrail drive mode and newel-wheel handrail drive mode, respectively. In <FIG>, a friction wheel <NUM> and the handrail <NUM> are shown. In <FIG>, a newel wheel <NUM> is shown. In these two different handrail drive modes, handrails move along different directions. Because a position to which a fixture for the temperature sensor assembly installs turns on a moving direction of the handrail, installation of the fixture presents different situations in the two handrail drive modes, which are introduced in detail below.

<FIG>, not claimed, demonstrate that the fixture <NUM> is installed on a C-profile component of the skirt panel in the frictional-wheel handrail drive mode. As shown in <FIG>, the fixture <NUM> is installed near the friction wheel and on the C-profile component of the skirt panel. The fixture comprises a bracket <NUM> and an adjustable plate <NUM>. The adjustable plate <NUM> is installed on the bracket through connection means such as bolts and nuts. The bracket <NUM> is installed on the C-profile component of the skirt panel through bolts and nuts. The temperature sensor assembly <NUM> is installed on the end of the adjustable plate <NUM> far away from the C-profile component.

One of the adjustable plate <NUM> and the bracket <NUM> has a first elongated hole extending along the length direction, and the other has an opening. Bolts may pass through the first elongated hole and the opening, thereby connect the adjustable plate and the bracket, and adjust distance A between the temperature sensor assembly and the C-profile component along the length direction based on the alignment positions of the opening relative to the first elongated hole along the length direction. Thus a handrail center distance L can be changed so as to adapt to different types of escalators.

<FIG>, not claimed, demonstrate that the fixture <NUM> is installed on a pillar in the newel-wheel handrail drive mode. As shown in <FIG>, the fixture is installed on the pillar. The fixture <NUM> comprises a bracket <NUM> and an adjustable plate <NUM>. The adjustable plate <NUM> is installed on the bracket through connection means such as bolts and nuts. The bracket <NUM> is installed on the pillar through bolts and nuts. The temperature sensor assembly <NUM> is installed on the end of the adjustable plate far away from the pillar.

One of the adjustable plate and the bracket has a second elongated hole <NUM> extending along the width direction perpendicular to the length direction, and the other has a third elongated hole <NUM> extending along the length direction. Bolts may pass through the second and third elongated holes, and thus connect the adjustable plate and the bracket. They also adjust the distance between the temperature sensor assembly and the pillar along the length direction (handrail center distance L) and the distance between the temperature sensor assembly and the handrail along the width direction W, based on the alignment positions of the second and third elongated holes.

<FIG> illustrates a flow chart in accordance with the not claimed first embodiment of the monitoring method. At step <NUM>', the temperature sensor assembly is used to detect ambient temperature and the temperature of the handrail of an escalator when it is turned off, in idling condition, or in full operating condition. At step <NUM>', a data transferring unit is used to receive the ambient temperature and the temperature of the back surface of the handrail from the temperature sensor assembly and transfer the ambient temperature and the handrail back surface temperature to a local data processing device or a cloud processor in a predetermined frequency. At step <NUM>', the server compares the ambient temperature with the handrail back surface and obtains the temperature difference between the ambient temperature and the handrail back surface, and a predetermined temperature difference threshold is stored in the local data processing device or the cloud processor. If the temperature difference between the ambient temperature and the temperature of the back surface of the handrail back surface exceeds the predetermined temperature difference threshold, the server will send an alarm signal.

At step <NUM>', the server further captures the temperature of the back surface of the handrail and the ambient temperature detected by the temperature sensor assembly in a predetermined period and compare the ambient temperature and the temperature of the back surface of the handrail, obtains a first mean value and a first variance of the temperature difference between the ambient temperature and the temperature of the back surface of the handrail in the predetermined period.

At the step <NUM>', the server further captures the temperature of the back surface of the handrail and the ambient temperature detected by the temperature sensor assembly in another predetermined period and compares the ambient temperature and the temperature of the back surface of the handrail, and obtains a second mean value and a second variance of the temperature difference between the ambient temperature and the temperature of the back surface of the handrail in this another predetermined period.

At the step <NUM>', the server is configured that the server sends a first alarm signal when the difference between the second mean value and the first mean value is k times greater than the first variance, wherein k, set in the server, is an integer greater than <NUM>.

At the step <NUM>', the server is further configured the server determines relation between the first variance and a predetermined first threshold and relation between the second variance and a predetermined second threshold, and if the first variance is smaller than the first threshold and the second variance is smaller than the second threshold, the server will send a second alarm signal.

The escalator monitoring system allows real-time monitoring of the operating condition of the handrails. Possible issues can be known in advance, and thus a safer escalator is provided. Furthermore, the real-time monitoring device applies to different installation circumstances of an escalator, and the fixture for the temperature sensor assembly is adjustable. The installation position of the fixture can be adjusted in light of different installation dimensions of various types of escalators.

With respect to <FIG>, a flow chart with respect to the eighth embodiment of the escalator monitoring system in accordance with the present invention is described in detail. The embodiment relates to monitoring of passenger traffic of the escalator monitoring in accordance with the present invention.

<FIG> is a block diagram of the escalator monitoring system in accordance with the present invention. The monitoring system <NUM> comprises passenger traffic sensor <NUM>, motor power sensor <NUM>, data transmittal unit <NUM>, and server <NUM>. The passenger traffic sensor <NUM> is means installed at the entrance of an escalator for emitting light beams in opposing directions, and the frequency of the light beams being interrupted reflects the passenger traffic entering onto the escalator. The motor power sensor <NUM> is so configured as to detect motor power consumption per unit time. The data transmittal unit <NUM> collects the passenger traffic and the motor power consumption per unit time, and transmits them to the server <NUM> by ways such as <NUM>, <NUM>, or <NUM>. The server <NUM> calculates the ratio (KPI) of the passenger traffic per unit time to the motor power consumption per unit time, and compares the ratio against a pre-determined ratio stored in the server <NUM>. If the ratio KPI shows abnormal changes as compared with the pre-determined ratio, the server predicts the time when the predicted failure will occur and sends out predictive maintenance signals. For example, the numeral "<NUM>" shown in <FIG> illustrates that the ratio of the passenger traffic per unit time to the motor power per unit time increases suddenly, which indicates that the passenger traffic at that time is not comparable to the motor power consumption and that the escalator is malfunctioning. Persons in the art will appreciate that the passenger traffic per unit time is a ratio of whole passenger traffic in a period of time and the time, and the whole passenger traffic in the time should not be too small.

<FIG> and <FIG> show two incomparable relationships between the passenger traffic per unit time and the motor power consumption per unit time, respectively. <FIG> illustrates that if the passenger traffic sensor detects no traffic yet the motor power consumption detected by the power sensor is incomparable to a predetermined power consumption under the situation that there is no passenger traffic, the escalator is considered as malfunctioning and the server sends out an alarm signal. <FIG> illustrates that if the passenger traffic sensor detects at least some traffic yet the motor power consumption is operating under idling condition during a period of time beyond a pre-determined threshold value, the escalator may suddenly speed up, causing passenger falling down and suffering an injury, and the server sends out alarm signals.

In addition, when there is no passenger traffic, the power sensor detects a mean power consumption in a predetermined period of time. A predetermined threshold range is stored in the server. If the mean power consumption falls into the predetermined threshold range stored in the server, the server sends out an alarm signal.

<FIG> illustrates a flow chart of the second embodiment of the monitoring method of an escalator in accordance with the present invention.

At step <NUM>, a passenger traffic sensor is used to detect the passenger traffic entering onto an escalator per unit time. At step <NUM>, a power sensor is used to detect the motor power consumption per unit time. At step <NUM>, a data transferring unit is used to transfer the people traffic detected in a unit time and the power consumption detected in a unit time to a server. At step <NUM>, the server determines the running condition of the escalator according to relation between the people traffic in a unit time and the power consumption in a unit time to determine whether or not an alarm signal needs to be sent.

In addition, at step <NUM>, the server further calculates a ratio between the power consumption in a unit time and the people traffic in a unit time and if the ratio abnormally changes, the server will send an alarm signal and if the ratio does not abnormally changes but has a tendency to increase in a predetermined time and goes beyond a predetermined threshold, the server will send an alarm signal.

In addition, in the case that the escalator is in a standby running condition, at the step <NUM>, the power sensor detects an average power in a predetermined period, and at the step <NUM>, if the average power does not fall in a predetermined threshold range stored in the server, the server will send an alarm signal.

At step <NUM>, the server is further configured that in a period beyond a predetermined threshold period, if the people traffic sensor detects that the people traffic is <NUM> and the power sensor detects that the power consumption is not comparable to a set power consumption when the people traffic is <NUM>, the server will send an alarm signal.

At step <NUM>, the server is further configured that in a period beyond a predetermined threshold period, if the people traffic sensor detects that the people traffic is not <NUM> and the power sensor detects that the power consumption is a standby power output, the server will send an alarm signal.

The real-time monitoring device according to the present invention allows real-time monitoring of the relationship between passenger traffic and power output and is informed of the operating condition of an escalator, thus improving the maintenance of the escalator, ameliorating its energy consumption, and making it safer.

The server mentioned in the specification may be a local server along with the data collection device, or a cloud processor capable of remote monitoring. All data may be processed at the local processor only, or at the cloud processor only, or, as explained in an embodiment above, at the local processor for some of work and then at the cloud processor for the rest. The present invention incorporates herein various embodiments based on these conceptions and is not limited to those embodiments described above.

Claim 1:
An escalator monitoring system, comprising a data collection device (<NUM>) disposed near parts of an escalator that need to be monitored for collecting data of the parts; a data transmittal device (<NUM>) used to transmit data relevant to safe operation of the escalator; a local data processing device (<NUM>) or cloud processors (<NUM>) used to receive the data relevant to the safe operation of the escalator, to compare it against a threshold value stored therein and derived from the parts in normal operating conditions, and to respond to comparison result,
characterized in that the data collection device (<NUM>) is a people traffic sensor for detecting the people traffic entering the escalator in a unit time, and an power sensor for detecting the power consumption in a unit time, a data transferring unit transfers the people traffic detected in a unit time and the power consumption detected in a unit time to the local data processing device (<NUM>) (<NUM>) or the cloud processors (<NUM>), the local data processing device (<NUM>) or the cloud processors (<NUM>) determines the running condition of the escalator according to the relation between the people traffic in a unit time and the power consumption in a unit time to determine whether or not an alarm signal needs to be sent.