HK1168578B - Apparatus and method for automatically adjusting safety control parameters of a conveyor - Google Patents

Description

Apparatus and method for automatically adjusting safety control parameters of a conveyor

Technical Field

The present disclosure relates generally to safety control systems and, more particularly, to an apparatus and method for automatically adjusting and calibrating parameters within a safety control system for a conveyor.

Background

Conveyors such as escalators, moving walks, moving walkways, and the like provide a path of motion to quickly and conveniently transport people from one location to another. More specifically, the moving pallets or steps of the conveyor move passengers along the length of the path between two landings at a predetermined rate. A step chain hidden from view and disposed below the conveyor serves to interconnect the steps in a closed loop manner. Driven by a primary drive source, a drive shaft, and associated sprockets, the step chain moves the steps along the exposed upper surface of the conveyor to transport passengers between landings. Sprockets provided in each of the two landings guide the step chain through an arc to reverse the direction of step movement and create a cyclical return path.

Because of their continuous motion, conveyors are prone to various internal failures, which can further result in injury to passengers on or near the conveyor. One such fault is associated with the speed of the conveyor or the speed at which the steps of the conveyor travel between landings. The speed of the conveyor may deviate from or fluctuate relative to the predefined nominal speed, resulting in steps of the conveyor moving too fast, moving too slow, stalling, accelerating too fast, etc. Inconsistencies in the speed of the conveyor can be caused by several factors. However, in most cases, inconsistencies in the speed of the conveyor can be caused by fluctuations in the power supplied to the primary drive source of the conveyor. For example, over-voltages, under-voltages, power surges, spikes, or other inconsistencies in the power supplied to the transmitter may cause variations in the transmitter that accumulate over time and eventually shift the predefined nominal speed of the transmitter. Power fluctuations may also hinder the ability of the transmitter to stop within a predefined time or distance as required by safety protocols.

Other faults are associated with misaligned or missing pallets or steps. Over time, one or more steps of the conveyor may become disengaged from the associated step chain, causing the steps to fall or fall below the conveyor system undetected. Missing steps may also result from improper maintenance. Conveyors require regular maintenance wherein one or more steps can be removed, replaced, etc. However, if the steps are not properly fastened or realigned with the step chain, the steps may come loose and fall. In any event, if the control system of the conveyor fails to detect a void caused by a missing step, the conveyor can continue to run, advancing the void to the upper surface of the conveyor, and exposing the void to passengers. An unknowing passenger may fall or step into the void and become injured.

Escalators and moving walkways are therefore provided with various safety measures to minimize the hazards caused by such fault conditions. For example, periodic maintenance may be performed on site by a service technician to ensure proper operation of the conveyor. However, such maintenance is timely, expensive, and introduces a risk of human error. Other security measures may employ security monitoring devices. In particular, the conveyor may be provided with a safety monitoring device which monitors the operational fault condition of the conveyor. When a fault has been detected, the safety monitoring device may be configured to transmit corrective instructions to the control unit of the conveyor, or simply to suspend operation of the conveyor until the fault is manually cleared by a service technician. However, the transmitter may also be required to operate in compliance with safety regulations and regulations associated with the transmitter type, location, application, and the like. Since the type, location and application of each conveyor is different, the safety monitoring devices associated with each conveyor must also be different.

In particular, the safety monitoring devices for each conveyor must be specifically designed, constructed and preprogrammed for that particular conveyor, which amounts to a significant amount of time and money spent building each conveyor system. This also means that existing safety devices are not suitable for any other conveyor type or application and additionally cannot be upgraded to comply with changing conditions, such as new conveyor safety regulations and regulations. To comply with changing safety regulations and regulations, currently existing safety devices or conveyor systems may need to be entirely replaced. Such maintenance requires considerable money and downtime for the end user.

Therefore, there is a need for a robust and versatile control system that monitors safety parameters of a conveyor system in a more timely and cost-effective manner. More specifically, there is a need for a safety control system that: it is adaptable to a wide variety of different conveyor types and local safety regulations, and additionally monitors the presence of conveyor steps, step speed, stopping distance, and other safety control parameters. Furthermore, there is a need for such a control system: it automatically determines the operating and mechanical characteristics of the associated conveyor, self-calibrates the necessary safety parameters, and monitors the parameters according to conveyor-specific safety regulations.

Disclosure of Invention

According to an aspect of the present disclosure, there is provided an apparatus for automatically adjusting a safety control parameter of a conveyor having a plurality of steps extending between a first platform and a second platform, the steps interconnected by a step chain and driven by a primary drive member. The apparatus comprises: a plurality of sensors configured to output at least a step speed signal and a step detection signal; and a safety control module in communication with the sensor and in communication with the conveyor control unit, the safety control module configured to automatically determine an operational characteristic and a mechanical characteristic of the conveyor based on an output of the sensor, verify the operational characteristic of the conveyor based on a predefined nominal specification, and determine a safety control parameter corresponding to the verified operational characteristic of the conveyor, thereby monitoring the conveyor operation.

According to another aspect of the present disclosure, a method is provided for automatically adjusting a safety control parameter of a conveyor having a plurality of steps extending between a first platform and a second platform, the steps interconnected by a step chain and driven by a primary drive member. The method comprises the following steps: determining an operating characteristic and a mechanical characteristic of the conveyor based on outputs of the step speed sensor and the step detection sensor; verifying an operational characteristic of the transmitter based on a predefined nominal specification; and determining a safety control parameter corresponding to the verified operating characteristic of the transmitter, thereby monitoring transmitter operation.

According to yet another aspect of the present disclosure, a method is provided for automatically adjusting a safety control parameter of a conveyor having a plurality of steps extending between a first platform and a second platform, the steps interconnected by a step chain and driven by a primary drive member. The method comprises the following steps: sampling output signals of a step speed sensor and a step detection sensor for a predefined period of time; determining an actual measured step speed based on the step speed output signal; determining a step speed sensor type based on a frequency of the step speed output signal; determining a conveyor step size based on a correlation between the step speed and the step detection output signal; comparing the measured step speed with a predefined step speed; comparing the cross-correlation between the sensor output signals to a predefined tolerance; and determining the safety control parameter only if both the measured step speed and the cross-correlation between the sensor output signals are within a predefined tolerance.

These and other aspects of the disclosure will become more readily apparent upon reading the following detailed description in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a perspective view of a conveyor incorporating an exemplary safety device for automatically adjusting safety control parameters constructed in accordance with the teachings of the present disclosure;

FIG. 2 is a schematic diagram of an exemplary conveyor system incorporating an automated safety control device; and

fig. 3 is a flow chart of an exemplary learn-run method for automatically adjusting safety control parameters of a conveyor.

While the disclosure is capable of various modifications and alternative constructions, certain illustrative embodiments thereof are shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the disclosure to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure.

Detailed Description

Referring to the drawings and in particular to fig. 1, an exemplary safety device for a conveyor is provided and indicated by reference numeral 100. It is understood that the teachings of the present disclosure may be used to construct devices for automatically adjusting safety control parameters as described above in addition to those specifically disclosed below. Those of ordinary skill in the art will readily appreciate that the following are only exemplary embodiments.

As shown in fig. 1, an exemplary conveyor 10 in the form of an escalator is provided having a first platform 12, a second platform 14, a plurality of moving pallets or steps 16 extending between the first and second platforms 12, 14, and a handrail 18 disposed alongside the plurality of steps 16. Steps 16 of conveyor 10 are driven by a primary drive source 17 (e.g., an electric motor, etc.) and are caused to move between platforms 12, 14. The primary drive source 17 rotates the drive shaft and associated gears to rotate a closed loop step belt or chain that mechanically interconnects the inner surfaces of the steps 16 within the slave conveyor 10. Within each of the two landings 12, 14, a sprocket 19 guides the step chain and attached steps 16 through an arc to reverse the direction of step movement and create a return path in a cyclical manner. The handrail 18 is rotatably moved alongside the steps 16 by a similar mechanism at a speed comparable to the speed of the steps 16.

Still referring to fig. 1, the conveyor 10 may be provided with a conveyor control unit 90 and a safety device 100 as shown. In general, the conveyor control unit 90 may be used to manage the overall operation and control of the conveyor system. The safety device 100 may be used to ensure that the conveyor 10 operates in accordance with associated safety regulations and regulations. The security device 100 may also be used according to other criteria, such as those set forth by the facility in which the transmitter is installed, contract agreements, user-defined specifications, and the like. The safety device 100 may include a plurality of sensors 102, 104, 106, 108 for observing various parameters of the conveyor 10 and a safety control module 200. Specifically, the safety device 100 may observe the transmission speed or step speed of the conveyor 10, the speed of the handrail 18, the presence or absence of steps 16 associated with each of the landings 12, 14, and the like. To determine the step speed, the safety device 100 can provide a step speed sensor 102, such as a photosensor, positioned proximate to the teeth 20 of the sprocket 19 of the step chain driving the interconnected steps 16. Alternatively, the step speed sensor 102 may include an encoder positioned on the axis of the sprocket 19 configured to detect the rotational speed of the sprocket 19. To detect the presence or absence of steps 16, safety device 100 may include step detection sensors 104, 106 in landings 12, 14 of conveyor 10. Specifically, the step detection sensors 104, 106 may include proximity sensors configured to detect metal in step rollers or step roller shafts of the pallet or step 16. The safety device 100 may also include a handrail sensor 108 to observe the relative speed of the handrail 18 with respect to the speed of the steps 16. The safety control module 200 may sample the sensor output to first learn the operational and mechanical characteristics of the conveyor 10, verify the measured data, automatically adjust safety control parameters based on the learned characteristics and safety regulations, and otherwise monitor the conveyor operation for any significant signs of failure or deviation. Once such a fault has been detected, the safety control module 200 may accordingly provide the transmitter control unit 90 with the necessary instructions for adjusting the transmitter operation.

Referring now to fig. 2, an overall schematic of an exemplary conveyor system incorporating an automatically adjusting safety device 100a is provided. More specifically, the main components of the overall system may include at least a conveyor 10a, a conveyor control unit 90a, and a safety device 100 a. As in the embodiment of fig. 1, various sensors 102a may be disposed on the conveyor 10a and within the conveyor 10a to measure or sample data specific to the conveyor 10a for a predefined period of time during normal operation of the conveyor 10 a. When activated, the safety control module 200a may use the sampled data provided by the sensor 102a to learn the operating characteristics and mechanical characteristics of the conveyor 10 a. Depending on the type of sensor 102a provided, the safety control module 200a may use the sampled data to determine characteristics such as conveyor step speed, step size, step pitch, handrail speed, associated gear ratios, and the type of sensor being used.

Once all the required data of the transmitter 10a is obtained, the safety control module 200a may verify the sampled data or compare the sampled data with predefined nominal values and thresholds. The predefined values may include nominal conveyor step speeds, step sizes, etc., as set forth by local safety regulations and regulations. The predefined values may also incorporate constraints or limitations introduced by other criteria (e.g., contract-specific requirements, user-defined preferences, etc.). If the sampled data is within an acceptable threshold of the predefined nominal value, the safety control module 200a may proceed to determine the appropriate safety function and corresponding safety control parameters specific to the transmitter 10 a. However, if the sampled data is not within an acceptable threshold of the predefined nominal value, the security control module 200a may reject the sampled data and proceed to obtain subsequent transmitter data samples until verification is successful. If the sampled data is valid and complies with the corresponding safety regulations and regulations, the safety control module 200a may automatically generate a new safety function specific to the transmitter, or automatically adjust an existing safety function previously stored within the safety device 100 a. More specifically, the safety control module 200a may calibrate the safety control parameters according to predefined values and store the safety control parameters within the safety device 100a for reference.

Using the safety function as a reference, the safety control module 200a may further monitor the operation of the conveyor 10a for any significant deviation from nominal specifications. If such a deviation is detected, the safety control module 200a may transmit the necessary signals to the transmitter control unit 90a to correct the error. For example, if the safety device 100a detects a significant increase in conveyor step speed, the safety control module 200a may instruct the control unit 90a to slow down. In response, the control unit 90a can reduce the power to the motor driving the conveyor 10a, etc., in order to reduce the conveyor step speed. Once the conveyor step speed returns to a speed within acceptable limits, the safety control module 200a may instruct the control unit 90a to stop decelerating and maintain the current step speed, as set forth by the stored safety function. Thus, the conveyor control unit 90a may then maintain the power delivered to the motor.

Referring back to the embodiment of FIG. 1, the safety control module 200 may be implemented using a microcontroller, microprocessor, or the like provided within the control panel of the transmitter 10 so as to be easily accessible by a service technician. The safety device 100 may further include a display or user interface through which a service technician may view or modify the transmitter data. Using such an interface, a service technician may also update the safety control module 200 according to changing safety procedures and regulations. To adjust or calibrate the safety control parameters of the conveyor 10 according to the new safety requirements, the service technician need only instruct the safety control module 200 to initiate the learn-run 300.

As disclosed herein, the learn-run 300 may be an algorithm preprogrammed within a microprocessor, microcontroller, or the like to run in accordance with the steps schematically illustrated by the flow chart of fig. 3. Before performing the learn-run 300, the learn-run 300 may require one or more prerequisites. For example, the learn-run 300 may require the conveyor 10 to run at a constant speed for a predetermined duration. If the conveyor 10 is an escalator, the learn-run 300 may require the escalator to run at a constant speed in a particular direction (up or down) before advancing. The learn-run 300 may also require predefined inputs that may be provided at the time of manufacture or by a service technician in the field. The predefined inputs may be discrete values that specify one or more constraints that the transmitter 10 should desirably comply with. For example, the learn-run 300 may require one or more discrete nominal conveyor step speeds, step or pallet sizes, etc., that are acceptable to safety standards.

Once all prerequisites are met and the necessary predefined inputs are received by the safety control module 200, the learn-run 300 may wait for manual input or instructions from the user to initiate the learn-run 300. Upon receiving a start command, the learn-run 300 may first execute a learn sequence 302. During the learn sequence 302, the learn-run 300 may use the various sensors 102, 104, 106, 108 to observe normal operating conditions of the conveyor 10 for a predefined period of time. For example, the learning sequence 302 may sample the data measured by the step speed sensor 102, the step detection sensors 104, 106, the handrail sensor 108, etc. for a period of about 40 seconds. Based on the sampled data, the learning sequence 302 may then perform an averaging operation and an addition operation to derive key characteristics of the transmitter 10. Specifically, the learning sequence 302 may be configured to calculate the measured step speed of the conveyor 10, the average period of each step detection signal, the average period of the step speed signals, the average number of step speed signal pulses per period of the step detection signals, the average frequency of the step speed signals, the average period of the handrail signals, and the like. Using such a derivation, the learn-run 300 may be able to determine various mechanical characteristics of a particular conveyor 10. In particular, the learning sequence 302 may be capable of determining the type of step speed sensor 102, proximity sensor, or encoder being used based on the frequency of the step speed signal provided by the step speed sensor 102. The learning sequence 302 can also determine conveyor step size, depth, and/or step pitch based on the number of step speed signal pulses per cycle of the step detection signal.

After the operational and mechanical characteristics of the conveyor 10 have been learned during the learning sequence 302, the learn-run 300 may then proceed to the verification sequence 304 of FIG. 3. In the verification sequence 304, the measured step speed of the conveyor 10 may be compared to a predefined step speed. As previously discussed, the safety control module 200 may be preprogrammed and set with a range of acceptable nominal step speeds. The verification sequence 304 may compare the measured step speed to each of the available predefined step speeds, e.g., 0.50 m/sec, 0.65 m/sec, 0.75 m/sec, and 0.90 m/sec, to determine the best match, or the predefined step speed that is closest to the measured step speed. The verification sequence 304 may further determine whether the measured step speed is within a predefined tolerance (e.g., 5% or 10%) of the selected predefined step speed. As an additional measure, verification sequence 304 may further determine whether measurements sampled during learning sequence 302 cross-correlate with one another within a predefined tolerance. Depending on the result, verification sequence 304 may exit (reject) or continue learning-run 300. For example, the verification sequence 304 may be configured to exit the learn-run 300 only when the measured step speeds and the cross-correlations between the individual measurements are not within respective predefined tolerances. Alternatively, the verification sequence 304 may be configured to exit the learn-run 300 when any one of the measured step speeds and the cross-correlation between the individual measurements is not within a respective predefined tolerance. If the learn-run 300 is exited or suspended, the learn-run 300 may be restarted automatically or through manual user input.

If verification sequence 304 is successful, learn-run 300 may proceed to calibration sequence 306, as shown in FIG. 3. Based on the operating characteristics and mechanical characteristics of the conveyor 10, the calibration sequence 306 may automatically generate a new safety function for a particular conveyor 10 and store the safety function for reference. Alternatively, the calibration sequence 306 may automatically adjust the control parameters of the existing safety function. In particular, the safety function may include a series of safety control parameters or thresholds upon which the transmitter 10 is monitored. Safety parameters may include thresholds related to conveyor step speed, forward and reverse movement of steps, detection of missing steps, stopping distance, handrail speed, and the like. More importantly, the resulting safety function and its parameters are automatically calibrated according to predefined nominal step speeds in order to ensure compliance with safety regulations and regulations.

Based on the foregoing, it can be seen that the present disclosure can provide a safety device for a conveyor (e.g., escalator, moving walkway, etc.) that overcomes the deficiencies in the prior art. More specifically, the present disclosure provides a safety control device that can automatically adapt to any of a wide variety of conveyor types while ensuring compliance with conveyor-specific safety regulations and regulations. Being adaptable, the safety control module facilitates manufacturing, installation and maintenance of the conveyor in any environment. Being automated, the safety control module minimizes the downtime and expense required to service the conveyor. In addition, the safety control module additionally minimizes faults introduced by human error due to the reduced need for maintenance by a service technician.

While only certain embodiments have been set forth, alternatives and modifications will be apparent to those skilled in the art in light of the foregoing description. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure.

Claims (20)

1. An apparatus (100, 100a) for automatically adjusting a safety control parameter of a conveyor (10, 10a), the conveyor (10, 10a) having a plurality of steps (16) extending between a first platform (12) and a second platform (14), the steps (16) being interconnected by a step chain and driven by a primary drive member (17), the apparatus (100, 100a) comprising:

a plurality of sensors (102, 102a, 104, 104a, 106, 106a) configured to output at least a step speed signal and a step detection signal; and

a safety control module (200, 200a) in communication with the sensor (102, 102a, 104, 104a, 106, 106a) and in communication with a conveyor control unit (90, 90a), the safety control module (200, 200a) configured to automatically determine an operating characteristic and a mechanical characteristic of the conveyor (10, 10a) based on an output of the sensor (102, 102a, 104, 104a, 106, 106a), verify the operating characteristic of the conveyor (10, 10a) based on a predefined nominal specification, and determine a safety control parameter corresponding to the verified operating characteristic of the conveyor (10, 10a), thereby monitoring conveyor operation.

2. The apparatus (100, 100a) of claim 1, wherein the safety control module (200, 200a) further monitors operational characteristics of the conveyor (10, 10a) and transmits instructions to correct any significant deviation to the conveyor control unit (90, 90 a).

3. The apparatus (100, 100a) of claim 2, wherein the safety control module (200, 200a) monitors step speed, reverse motion, step detection, and stopping distance.

4. The apparatus (100, 100a) of claim 1, wherein the plurality of sensors (102, 102a, 104, 104a, 106, 106a, 108, 108a) are configured to further output a handrail speed signal.

5. The apparatus (100, 100a) of claim 1, wherein the operating characteristic is determined by at least calculating an average period of the step speed signal and an average period of the step detection signal.

6. The apparatus (100, 100a) of claim 1, wherein the mechanical characteristics include conveyor step size and step speed sensor type.

7. The apparatus (100, 100a) of claim 1, wherein the safety control module (200, 200a) verifies an operational characteristic of the conveyor (10, 10a) by comparing a measured step speed to a predefined step speed.

8. The apparatus (100, 100a) of claim 7, wherein the safety control module (200, 200a) further compares a cross-correlation between the sensor output signals to a predefined tolerance.

9. The apparatus (100, 100a) of claim 1, wherein the apparatus (100, 100a) further comprises a user interface through which the safety control module (200, 200a) displays information relating to operating characteristics of the conveyor (10, 10 a).

10. A method (300) for automatically adjusting a safety control parameter of a conveyor (10, 10a), the conveyor (10, 10a) having a plurality of steps (16) extending between a first platform (12) and a second platform (14), the steps (16) being interconnected by a step chain and driven by a primary drive member (17), the method (300) comprising the steps of:

determining operational and mechanical characteristics of the conveyor (10, 10a) based on outputs of a step speed sensor (102, 102a) and a step detection sensor (104, 104a, 106, 106 a);

verifying operating characteristics of the conveyor (10, 10a) based on a predefined nominal specification; and

-determining a safety control parameter corresponding to a verified operating characteristic of the conveyor (10, 10a), thereby monitoring conveyor operation.

11. The method (300) of claim 10, wherein the method (300) further comprises the steps of: the operating characteristics of the conveyor (10, 10a) are monitored and instructions for correcting any significant deviation are transmitted to a conveyor control unit (90, 90 a).

12. The method (300) of claim 10, wherein the step of determining the operational and mechanical characteristics of the conveyor (10, 10a) is further based on an output of a handrail sensor (108, 108 a).

13. The method (300) of claim 10, wherein the operational characteristics of the conveyor (10, 10a) include at least an average period of a step speed signal and an average period of a step detection signal.

14. The method (300) of claim 10, wherein the mechanical characteristics include conveyor (10, 10a) step size and step speed sensor type.

15. The method (300) of claim 10, wherein the step of verifying the operating characteristics of the conveyor (10, 10a) compares the measured step speed to a predefined step speed.

16. A method (300) for automatically adjusting a safety control parameter of a conveyor (10, 10a), the conveyor (10, 10a) having a plurality of steps (16) extending between a first platform (12) and a second platform (14), the steps (16) being interconnected by a step chain and driven by a primary drive member (17), the method (300) comprising the steps of:

sampling output signals of a step speed sensor (102, 102a) and a step detection sensor (104, 104a, 106, 106a) for a predefined period of time;

determining a measured step speed based on an output signal of the step speed sensor (102, 102 a);

determining a step speed sensor type based on a frequency of an output signal of the step speed sensor (102, 102 a);

determining a conveyor step size based on a correlation between an output signal of the step speed sensor (102, 102a) and an output signal of the step detection sensor (104, 104a, 106, 106 a);

comparing the measured step speed to a predefined step speed;

comparing a cross-correlation between the output signal of the step speed sensor (102, 102a) and the output signal of the step detection sensor (104, 104a, 106, 106a) to a predefined tolerance; and

determining a safety control parameter only if both the measured step speed and the cross-correlation are within a predefined tolerance.

17. The method (300) of claim 16, wherein the step of sampling the output signal further samples the output signal of the handrail sensor (108, 108a) for the predefined period of time.

18. The method (300) of claim 16, wherein the step of sampling the output signal is initiated in response to a user input and only during normal transmitter operation.

19. The method (300) of claim 16, wherein a number of step speed signal pulses per cycle of the output signal of the step detection sensor is used to determine a correlation between the output signal of the step speed sensor and the output signal of the step detection sensor.

20. The method (300) of claim 16, wherein the safety control parameters include thresholds for step speed, reverse motion, step detection, and stopping distance.