Escalator step chain dynamic tension distribution type measuring system and method

Abstract

This invention provides a distributed dynamic tension measurement system and method for escalator step chains. The system includes a step chain composed of multiple sequentially connected links, a computing platform, and a data aggregation base station. Several links are designated as intelligent links, each comprising a link body, a force sensor, an inertial measurement unit, a self-powered unit, a positioning module, and a wireless communication unit. The force sensor, inertial measurement unit, and positioning module are wirelessly connected to the data aggregation base station via the wireless communication unit. The computing platform is electrically connected to the data aggregation base station. Based on the positioning signal, axial tension, acceleration, angular velocity, and attitude angle of each intelligent link, the computing platform determines the actual tension value and position information of each intelligent link. This invention overcomes the shortcomings of traditional step chain tension detection methods.

Description

Technical Field

[0001] This invention belongs to the field of escalator technology, and particularly relates to a distributed measurement system and method for dynamic tension of escalator step chains. Background Technology

[0002] The escalator step chain is its core transmission and load-bearing component, and it withstands complex dynamic loads during operation. Uneven distribution of step chain tension or instantaneous overload is one of the main causes of safety accidents such as chain fatigue fracture, tooth skipping, and even escalator reverse rotation.

[0003] Traditional escalator chain tension detection mainly relies on manual inspection after shutdown, using tension gauges or strain gauges to perform single-point measurements at local locations. This method has the following drawbacks: (1) Non-real-time: It cannot reflect the dynamic tension changes during escalator operation; (2) Single-point limitation: It cannot obtain the tension distribution at each link and roller on the entire escalator chain; (3) Ignoring dynamic effects: It cannot capture transient impact loads under conditions such as start-up, shutdown, off-center loading, and obstruction by foreign objects; (4) Difficult installation: Traditional strain gauges or tension sensors are difficult to transmit signals and supply power on continuously moving chains. Summary of the Invention

[0004] The purpose of this invention is to provide a distributed dynamic tension measurement system for escalator step chains, which can solve the shortcomings of traditional step chain tension detection.

[0005] This invention is achieved through the following technical solution: A distributed dynamic tension measurement system for an escalator step chain includes a step chain composed of multiple links connected sequentially, a computing platform, and a data aggregation base station. Several of the links are intelligent links, each comprising a link body, a force sensor, an inertial measurement unit, a self-powered unit, a positioning module, and a wireless communication unit. The force sensor is installed within a pin in the link body to measure the axial tension of the intelligent link. The inertial measurement unit and the self-powered unit are installed on the link body links. The inertial measurement unit measures the acceleration, angular velocity, and attitude angle of the intelligent link. The positioning module collects the positioning signal of the intelligent link. The self-powered unit is electrically connected to the force sensor, the inertial measurement unit, the positioning module, and the wireless communication unit to convert the vibration of the link body into electrical energy. The force sensor, the inertial measurement unit, and the positioning module are wirelessly connected to the data aggregation base station via the wireless communication unit. The computing platform is electrically connected to the data aggregation base station. Based on the positioning signal, axial tension, acceleration, angular velocity, and attitude angle of each intelligent link, the computing platform determines the actual tension value and position information of each intelligent link.

[0006] Furthermore, the computing platform includes: The dynamic compensation module is used to calculate the actual axial tensile force borne by the smart link based on the axial tension, acceleration, and angular velocity of the smart link. The position calibration module is used to determine the position information of the smart link based on the positioning signal; The continuous medium reconstruction module is used to reconstruct the actual tension value of each link of the ladder chain after the ladder chain has rotated at least one revolution, based on the actual axial tension and position information of each smart link.

[0007] Furthermore, the computing platform also includes: The anomaly diagnosis module is used to determine the maximum tension value, tension unevenness, and dynamic impact coefficient based on the actual tension value of each link of the ladder chain. If any of the maximum tension, tension unevenness, or dynamic impact coefficient exceeds a preset threshold, a warning or shutdown signal will be issued.

[0008] Furthermore, in the dynamic compensation module, the formula for calculating the actual axial tensile force borne by the smart link is as follows: Freal(i,t)=Fraw(i,t) m at(i,t) Ffric(i,t) (1) In the formula, Freal(i,t) is the actual axial tension, Fraw(i,t) is the axial tension measured by the force sensor, m is the equivalent mass of the chain link, at(i,t) is the tangential acceleration along the chain direction, and Ffric is the dynamic friction force model between the pin and the chain link.

[0009] Furthermore, the smart link also includes a processing module. The force sensor and the inertial measurement unit are both connected to the wireless communication unit through the processing module. The processing module is used to preprocess the data collected by the force sensor and the inertial measurement unit.

[0010] Furthermore, the self-powered unit is a piezoelectric-electromagnetic composite energy harvester.

[0011] Furthermore, the positioning module is either a UWB module or a Bluetooth module.

[0012] This invention also provides a distributed method for dynamic tension of escalator step chains, applied to the aforementioned distributed measurement system for dynamic tension of escalator step chains. The method includes the following steps: Monitoring data is collected at a set frequency through each of the smart links, and the monitoring data includes the axial tension, acceleration, angular velocity, attitude angle and positioning signal of the smart links; For each monitoring data point, the actual axial tensile force borne by the smart link is calculated based on acceleration and angular velocity, and the position information of the smart link is determined based on the positioning signal. After the ladder chain has rotated at least one revolution, the actual tension value of each link of the ladder chain is reconstructed based on the actual axial tension and position information of each smart link acquired at a set frequency.

[0013] Compared with existing technologies, the advantages of this invention are as follows: by setting several intelligent links in multiple links of the ladder chain, and combining wireless power supply and data transmission, real-time, continuous and high-precision measurement of the tension at each key point of the ladder chain during operation is achieved, breaking through the limitations of traditional single-point measurement and realizing synchronous monitoring of tension at all key positions during the operation of the ladder chain; by adopting self-powered and wireless communication technology, there is no need to carry out large-scale modifications to the existing escalator structure, making installation and maintenance convenient. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the distributed dynamic tension measurement system for escalator step chains according to the present invention; Figure 2 This is a block diagram of the distributed dynamic tension measurement system for the escalator step chain of the present invention.

[0015] In the diagram, 1-link, 2-computing platform, 3-data aggregation base station, 4-force sensor, 5-inertial measurement unit, 6-self-powered unit, 7-positioning module, 8-wireless communication unit. Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0016] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0017] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0018] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the distributed dynamic tension measurement system for escalator step chains according to the present invention. Figure 2This is a block diagram of the distributed dynamic tension measurement system for escalator step chains according to the present invention. The present invention provides a distributed dynamic tension measurement system for escalator step chains, comprising a step chain composed of multiple link 1 connected sequentially. The system also includes a computing platform 2 and a data aggregation base station 3. Several of the link 1 are intelligent link 1s, each including a link body, a force sensor 4, an inertial measurement unit 5, a self-powered unit 6, a positioning module 7, and a wireless communication unit 8. The force sensor 4 is disposed within a pin in the link body and is used to measure the axial tension on the intelligent link. The inertial measurement unit 5 and the self-powered unit 6 are disposed on the link body link segments. Unit 5 is used to measure the acceleration, angular velocity, and attitude angle of the intelligent link. Positioning module 7 is used to collect the positioning signal of the intelligent link. Self-powered unit 6 is electrically connected to force sensor 4, inertial measurement unit 5, positioning module 7, and wireless communication unit 8 respectively, and is used to convert the vibration of the link body into electrical energy. Force sensor 4, inertial measurement unit 5, and positioning module 7 are wirelessly connected to data aggregation base station 3 through wireless communication unit 8. Computing platform 2 is electrically connected to data aggregation base station 3. Based on the positioning signal, axial tension, acceleration, angular velocity, and attitude angle of each intelligent link, computing platform 2 determines the actual tension value and position information of each intelligent link.

[0021] The escalator chain is composed of multiple links 1 connected sequentially. Each link 1 includes a chain piece, a pin, a bushing, and a roller. The pin passes through the chain piece, the bushing is fitted onto the pin, and the roller is mounted on the bushing. Several links 1 are selected, and a force sensor 4 is added to the pin of each selected link. An inertial measurement unit 5, a self-powered unit 6, a positioning module 7, and a wireless communication unit 8 are also added to the link, making this link 1 a smart link. Several smart links are spaced apart. The self-powered unit 6 powers the force sensor 4, inertial measurement unit 5, positioning module 7, and wireless communication unit 8, and the wireless communication unit 8 wirelessly connects to the data aggregation base station 3 and the reference node. This eliminates the need for large-scale modifications to the existing escalator structure, making installation and maintenance convenient. In one embodiment, the self-powered unit 6 is a piezoelectric-electromagnetic composite energy harvester.

[0022] The axial tensile force measured by force sensor 4 and the acceleration, angular velocity, and attitude angle measured by inertial measurement unit 5 are transmitted to data aggregation base station 3 via wireless communication unit 8. Data aggregation base station 3 can be installed inside the escalator truss to aggregate the data collected by force sensor 4, inertial measurement unit 5, and positioning module 7 and upload it to computing platform 2. Computing platform 2 is used to determine the actual tensile force value and position information of each smart link.

[0023] Furthermore, the smart link also includes a processing module. Both the force sensor 4 and the inertial measurement unit 5 are connected to the wireless communication unit 8 through the processing module. The processing module is used to preprocess the data collected by the force sensor 4 and the inertial measurement unit 5.

[0024] Specifically, the preprocessing process of the processing module includes noise removal and digital filtering. The noise removal process is as follows: first, the original analog signals of the force sensor 4 and the IMU inertial measurement unit 5 are amplified and hardware filtered, usually using a low-pass filter to remove high-frequency electrical noise above 1kHz. The digital filtering process is as follows: after the analog signal is converted into digital, a lightweight filtering algorithm (such as mean filtering, first-order low-pass IIR filter) is used to further smooth the data and eliminate short-term noise such as chain meshing impact.

[0025] Furthermore, computing platform 2 includes: The dynamic compensation module is used to calculate the actual axial tensile force borne by the smart link based on its axial tension, acceleration, and angular velocity. The formula for calculating the actual axial tensile force borne by the smart link is as follows: Freal(i,t)=Fraw(i,t) m at(i,t) Ffric(i,t) (1) In the formula, Freal(i,t) is the actual axial tension, Fraw(i,t) is the axial tension measured by force sensor 4, m is the equivalent mass of the smart link, at(i,t) is the tangential acceleration along the chain direction, Ffric is the dynamic friction force model between the pin and the chain link, which can be calculated by pre-calibrated friction coefficient and angular velocity. This is existing technology and will not be elaborated here. t is time.

[0026] The position calibration module is used to determine the position information of the smart link based on the positioning signal; Specifically, positioning module 7 is either a UWB module or a Bluetooth module. More specifically, the UWB module includes a UWB tag and multiple reference nodes. The UWB tag is mounted on the smart link, and the multiple reference nodes are fixedly mounted on the escalator truss, such as at the head, tail, and curved sections of the escalator truss. The UWB tag measures the distance between itself and each reference node in real time, and a positioning algorithm based on UWB and IMU fusion is used to calculate the absolute position of each smart link in real time, thus obtaining the position information of the smart link. This position information is then combined with attitude angles to determine whether it is on a straight segment, a horizontal segment, or a curved segment. Similarly, the Bluetooth module has an antenna array, and at least three AoA Bluetooth base stations are located indoors. A positioning algorithm based on Bluetooth AoA and IMU fusion is used to calculate the absolute position of each smart link in real time, thus obtaining the position information of the smart link. This position information is then combined with attitude angles to determine whether it is on a straight segment, a horizontal segment, or a curved segment.

[0027] The continuous medium reconstruction module is used to reconstruct the actual tension value of each link 1 of the ladder chain after the ladder chain has rotated at least one revolution, based on the actual axial tension and position information of each smart link.

[0028] Specifically, after the ladder chain rotates once, the smart link also rotates once, that is, the smart link passes through the position of each link 1. Thus, based on the actual axial tension obtained from the smart link, the actual tension value of each link 1 of the ladder chain can be reconstructed.

[0029] Furthermore, computing platform 2 also includes: The anomaly diagnosis module is used to determine the maximum tension value, tension unevenness, and dynamic impact coefficient based on the actual tension value of each link 1 of the ladder chain. If any of the maximum tension, tension unevenness, or dynamic impact coefficient exceeds a preset threshold, a warning or shutdown signal will be issued.

[0030] Specifically, after the ladder chain has rotated at least one revolution, the actual tension values ​​of the smart links during the rotation are compared. The maximum tension Tmax is obtained from the actual tension values ​​of the smart links, and the minimum tension Tmin is obtained. Then, based on the formula δ=(Tmax) The tension non-uniformity δ is calculated using the formula Tmax / Tavg, where Tmax is the maximum tension, Tmin is the minimum tension, and Tavg is the average tension. The dynamic impact coefficient kd is calculated based on the formula kd=Tpeak / Tstatic, where Tpeak is the dynamic load at a given moment, and Tstatic is the static load at a given moment. If any of the maximum tension Tmax, tension non-uniformity δ, or dynamic impact coefficient kd exceeds a preset threshold, it indicates a problem with the operation of the ladder chain, thus issuing a warning or shutdown signal to prompt maintenance personnel to perform repairs.

[0031] This invention also provides a distributed method for dynamic tension of escalator step chains, applied to the aforementioned distributed measurement system for dynamic tension of escalator step chains. The method includes the following steps: S1. Collect monitoring data at a set frequency through each of the intelligent links, the monitoring data including the axial tension, acceleration, angular velocity, attitude angle and positioning signal of the intelligent links; S2. For each monitoring data point, calculate the actual axial tensile force borne by the smart link based on acceleration and angular velocity, and determine the position information of the smart link based on the positioning signal; S3. After the ladder chain has rotated at least one revolution, the actual tension value of each link 1 of the ladder chain is reconstructed based on the actual axial tension and position information of each of the smart links obtained at a set frequency.

[0032] Furthermore, step S2 includes: Calculate the actual axial tensile force borne by the smart link based on its axial tension, acceleration, and angular velocity. The location information of the smart link is determined based on the positioning signal.

[0033] Furthermore, the method also includes: Based on the actual tension value of each link in the ladder chain, the maximum tension value, tension unevenness, and dynamic impact coefficient are determined. If any of the maximum tension, tension unevenness, or dynamic impact coefficient exceeds the preset threshold, an early warning or shutdown signal is issued.

[0034] Furthermore, the formula for calculating the actual axial tensile force borne by the smart link is as follows: Freal(i,t)=Fraw(i,t) m at(i,t) Ffric(i,t) (1) In the formula, Freal(i,t) is the actual axial tension, Fraw(i,t) is the axial tension measured by force sensor 4, m is the equivalent mass of the chain link, at(i,t) is the tangential acceleration along the chain direction, and Ffric is the dynamic friction force model between the pin and the chain link.

[0035] Furthermore, after step S1, the method also includes: The data collected by force sensor 4 and inertial measurement unit 5 are preprocessed.

[0036] For the method embodiments, since they are basically corresponding to the system embodiments, the relevant parts can be referred to in the description of the system embodiments.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A distributed dynamic tension measurement system for escalator step chains, comprising a step chain composed of multiple links connected sequentially, characterized in that, It also includes a computing platform and a data aggregation base station. Several of the multiple chain links are intelligent chain links. Each intelligent chain link includes a chain link body, a force sensor, an inertial measurement unit, a self-powered unit, a positioning module, and a wireless communication unit. The force sensor is installed inside the chain link body pin and is used to measure the axial tension of the intelligent chain link. The inertial measurement unit and the self-powered unit are installed on the chain links of the chain link body. The inertial measurement unit is used to measure the acceleration, angular velocity, and attitude angle of the intelligent chain link. The positioning module is used to collect the positioning signal of the intelligent chain link. The self-powered unit is electrically connected to the force sensor, the inertial measurement unit, the positioning module, and the wireless communication unit, respectively, and is used to convert the vibration of the chain link body into electrical energy. The force sensor, the inertial measurement unit, and the positioning module are wirelessly connected to the data aggregation base station through the wireless communication unit. The computing platform is electrically connected to the data aggregation base station. The computing platform determines the actual tension value and position information of each intelligent chain link based on the positioning signal, axial tension, acceleration, angular velocity, and attitude angle of each intelligent chain link.

2. The distributed dynamic tension measurement system for escalator step chains according to claim 1, characterized in that, The computing platform includes: The dynamic compensation module is used to calculate the actual axial tensile force borne by the smart link based on the axial tension, acceleration, and angular velocity of the smart link. The position calibration module is used to determine the position information of the smart link based on the positioning signal; A continuous medium reconstruction module is used to reconstruct the actual tension value of each link of the ladder chain after the ladder chain has rotated at least one revolution, based on the actual axial tension and position information of each of the smart links.

3. The distributed dynamic tension measurement system for escalator step chains according to claim 2, characterized in that, The computing platform also includes: The anomaly diagnosis module is used to determine the maximum tension value, tension unevenness, and dynamic impact coefficient based on the actual tension value of each link of the ladder chain. If any of the maximum tension, tension unevenness, or dynamic impact coefficient exceeds a preset threshold, a warning or shutdown signal will be issued.

4. The distributed dynamic tension measurement system for escalator step chains according to claim 2, characterized in that, In the dynamic compensation module, the formula for calculating the actual axial tensile force borne by the smart link is as follows: Freal(i,t)=Fraw(i,t) m at(i,t) Ffric(i,t) (1); In the formula, Freal(i,t) is the actual axial tension, Fraw(i,t) is the axial tension measured by the force sensor, m is the equivalent mass of the chain link, at(i,t) is the tangential acceleration along the chain direction, and Ffric is the dynamic friction force model between the pin and the chain link.

5. The distributed dynamic tension measurement system for escalator step chains according to claim 1, characterized in that, The smart link also includes a processing module. The force sensor and the inertial measurement unit are both connected to the wireless communication unit through the processing module. The processing module is used to preprocess the data collected by the force sensor and the inertial measurement unit.

6. The distributed dynamic tension measurement system for escalator step chains according to claim 1, characterized in that, The self-powered unit is a piezoelectric-electromagnetic composite energy harvester.

7. The distributed dynamic tension measurement system for escalator step chains according to claim 1, characterized in that, The positioning module is a UWB module or a Bluetooth module.

8. A distributed method for dynamic tension of escalator step chains, applied to the distributed measurement system for dynamic tension of escalator step chains as described in any one of claims 1-7, characterized in that, The method includes the following steps: Monitoring data is collected at a set frequency through each of the smart links, and the monitoring data includes the axial tension, acceleration, angular velocity, attitude angle and positioning signal of the smart links; For each monitoring data point, the actual axial tensile force borne by the smart link is calculated based on acceleration and angular velocity, and the position information of the smart link is determined based on the positioning signal. After the ladder chain has rotated at least one revolution, the actual tension value of each link of the ladder chain is reconstructed based on the actual axial tension and position information of each smart link acquired at a set frequency.

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