EP3026001B1

EP3026001B1 - Safety detection device of passenger conveying apparatus and implementation method thereof

Info

Publication number: EP3026001B1
Application number: EP13889832.5A
Authority: EP
Inventors: Cheng He; Jun Chen; Guoliang Wu; Yi Xin
Original assignee: Shanghai Mitsubishi Elevator Co Ltd
Current assignee: Shanghai Mitsubishi Elevator Co Ltd
Priority date: 2013-07-26
Filing date: 2013-11-13
Publication date: 2023-08-30
Anticipated expiration: 2033-11-13
Also published as: WO2015010392A1; EP3026001A1; CN104340835B; KR101923610B1; CN104340835A; EP3026001A4; KR20150114943A

Description

FIELD OF THE INVENTION

This application relates to a safety detection device of passenger conveying equipment as in the preamble of claim 1 and to a corresponding method according to the preamble of claim 6, especially to a safety detection device used for such matters as overspeed and non-manipulation inversion of the passenger conveying equipment. GB2263169A describes a brake stopping distance tester for an escalator or other passenger conveyer.

BACKGROUND OF THE INVENTION

Escalators and moving sidewalks are collectively referred to as passenger conveying equipment. The escalator, typically used for transporting passenger between different floors, is in the form of a step-shaped step or a slope-shaped footrest. The moving sidewalk, typically used for transporting passenger on a horizontal plane, is generally only in the form of a planar footrest. The escalator is basically similar to the moving sidewalk in structure and work principle.
As shown in Fig. 1, a step-shaped escalator is taken as an example to show the main structure of the passenger conveying equipment. A motor 11 and a reduction box 12 mainly compose a drive device 1, and an output sprocket 31 located in the reduction box 12 outputs torque. With a spindle 2 fixedly mounted at one end of the passenger conveying equipment, a drive sprocket 32, the first step sprocket 41, and the first handrail sprocket 51 are all rigidly mounted on the spindle 2 and rotate coaxially with the spindle 2. Fig. 1a is a partial enlarged view of the structure of each of the parts rotating coaxially with the spindle 2. The drive chain 33 surrounds the output sprocket 31 and the drive sprocket 32, transferring the torque of the output sprocket 31 to the drive sprocket 32. The second step sprocket 42 is located at the other end of the passenger conveying equipment. The step chain 43 surrounds the first step sprocket 41 and the second step sprocket 42, transferring the torque of the first step sprocket 41 to the second step sprocket 42. A plurality of steps 44 are closely arranged and fixed one by one on the step chain 43, and move together with the same. A half trip of each of the steps 44 is used for carrying passengers, and the other half trip for inversely turning around. Obviously, the step-shaped steps 44 in Fig. 1 can also be replaced by a slope-shaped footrest, and the escalator can also be replaced by a moving sidewalk. The second handrail sprocket 52 and the spindle 2 are located at the same end of the passenger conveying equipment. A handrail chain 53 surrounds the first handrail sprocket 51 and a friction wheel rotating coaxially with the second handrail sprocket 52, transferring the torque of the first handrail sprocket 51 to the second handrail sprocket 52. The second handrail sprocket 52 also drives a handrail 54 to move together through a friction mechanism, a tension mechanism and the like.
The work principle of the above passenger conveying equipment is as follows: A drive device 1 generates a driving force and the output sprocket 31 outputs torque which torque drives the drive sprocket 32 to rotate through the drive chain 33. The drive sprocket 32 also drives the spindle 2, the first step sprocket 41, and the first handrail sprocket 51 to rotate coaxially. The torque of the first step sprocket 41 drives the second step sprocket 42 to rotate through the step chain 43, and drives each of the steps 44 to move together with the step chain 43, thus transporting passengers on each of the steps 44 from one end to the other. The torque of the first handrail sprocket 51 drives the second handrail sprocket 52 to rotate through the handrail chain 53, and drives the handrail 54 to move.
The operating speed of the passenger conveying equipment should remain substantially constant; if the operating speed is beyond the preset range, particularly in case of overspeed movement, the passengers' personal safety will be in danger. In the movement process of the passenger conveying equipment, if there is an inversion movement on non-manipulation purpose, the passengers' personal safety will be obviously in greater danger. In addition, if the passenger conveying equipment has missing steps or footrests, once a passenger attempts to stand at this position, the passenger will fall or be caught in the movement mechanism of the passenger conveying equipment, resulting in a great safety risk. Therefore, safety risks such as overspeed movement, non-manipulation inversion and missing steps must be detected immediately by a safety detection device, and handled timely thereafter, e.g. by stopping operation of the passenger conveying equipment immediately.
A Chinese invention patent application having Publication No. CN1031686A and Publication date on Mar. 15, 1989 discloses a safety facility of the passenger conveying equipment that, by reserving a free gap on the side of the steps and comparing the periodic brightness change of a beam passing through the free gap when each step moves, detects speeding, inversion and step faults of the passenger transport device. However, it requires a plurality of steps to go through the raster to judge the brightness waveforms of the fault, which makes the response speed quite slow and can thus only be used as a supplementary protection measure.
A Japanese invention patent application having Publication No. JP2008143695A and Publication date on Jun. 26, 2006 discloses a speed detection device of the passenger conveying equipment, which obtains the speed and direction of the passenger conveying equipment by detecting the speed and direction of the drive chain. However, this solution is hard to really apply, mainly because it is hard to find a suitable position for mounting a sensor. The drive chain may vibrate in the movement process with considerable amplitude, and suffer from chain slack and other problems, thus it is prone to misjudge its movement speed, and its practicability is poor.
A Chinese invention patent application having Publication No. CN101365644A and Publication date on Feb. 11, 2009 discloses a movement direction detection device of the passenger conveying equipment, which is mounted on an output shaft of the drive device and detects the movement direction of the passenger conveying equipment by triggering a mechanical switch. However, the contact-type detection suffers from severe mechanical wear, and needs to be maintained and checked periodically, which brings inconvenience to a user. More crucially, it is only applicable in the case that the drive chain works normally. Once the drive chain is broken, abnormally displaced (i.e. the drive chain escapes from the output sprocket or the drive sprocket) or has other faults, although the drive device itself runs normally, the drive sprocket, the two step sprockets, the step chain and steps, the two handrail sprockets, the handrail chain, and the handrail have lost the driving force which may cause serious accidents such as stall, inversion, and even accelerated decline under the gravity function of passengers.
A Chinese invention patent application having Publication No. CN102167257A and Publication date on Aug. 31, 2011 discloses a host safety device of the passenger conveying equipment, which detects speeding and inversion of the passenger conveying equipment through detection of the rotary speed and movement direction of the output shaft of the drive device. Likewise, it cannot be used in the case of broken drive chain, abnormal displacement or other faults.
A Chinese invention patent application having Publication No. CN102464259A and Publication date on May 23, 2012 discloses a monitoring device of the passenger conveying equipment, which is provided with a primary speed sensor at the drive device and with a secondary speed sensor at the step sprocket or the step chain. The primary speed sensor has a fast response speed, but cannot make accurate detection when the drive chain is abnormal. The secondary speed sensor has a slow response speed, but can detect a fault when the drive chain is abnormal. It detects speeding and inversion of the passenger conveying equipment through a redundant sensor, having the disadvantage of complex structure and high cost.
A Chinese invention patent application having Publication No. CN102935971A and Publication date on Feb. 20, 2013 discloses a protective device of the passenger conveying equipment, which judges the movement direction through a sensor provided in alignment with the teeth of the drive sprocket, and then makes the inversion detection. However, this method has the following two shortcomings: 1) Because the direction judgment is made based on the phase overlap region and phase difference of the waveforms outputted by the two sensors, the tooth region detected by the two sensors must has a larger overlap region, which requires that the teeth of the drive sprocket must have an outer-edge width great enough, with the width at least close to the size of the end face of the sensor (generally over 15 mm). This makes this method only applicable to a drive sprocket having a particular tooth form, but not applicable to the tooth form of most drive sprockets, resulting in a narrow application scope. 2) With one pulse outputted when each tooth passes, the detection principle is of an incremental type, disenabling this solution to judge the fault that the sensor regularly outputs a pulse of particular frequency.
A Chinese invention patent application having Publication No. CN103010920A and Publication date on Apr. 3, 2013 discloses a protective device of the passenger conveying equipment, which detects the movement speed and movement direction of the output shaft of the drive device through an encoder, thus detecting speeding and inversion of the passenger conveying equipment. First, it cannot be used in the case of broken drive chain, abnormal displacement or other faults. Second, a rotary encoder, although having higher speed measurement precision, has the shortcoming of being more fragile and vulnerable to damage, and thus can be easily damaged by shake, vibration, etc. of the output shaft of the passenger conveying equipment.
In addition, a combined solution easy to be thought of is a rotary encoder mounted on the spindle, which can satisfy the requirement of speed measurement precision, with the detection position also closer to the steps in actual movement. However, damage can be easily caused to the encoder by the normal shake and vibration occurred in the normal operating of the spindle of the passenger conveying equipment, making this combined solution not practical.
Based on the above various existing safety detection devices of the passenger conveying equipment, it can be found that the prior arts and the combination thereof are difficult to realize accurate detection of speed and direction in the case of the faults of broken drive chain or abnormal displacement. It is still a problem for the industry how to provide a safety detection device that has rapid response, easy to be implemented, and stable and reliable to be operated, covering speeding movement, non-manipulation inversion and other safety risks due to a variety of fault reasons (at least including the output fault of the drive device, the broken drive chain, the abnormal displacement of the drive chain, and the like).

CONTENTS OF THE INVENTION

Technical problems

The technical problem to be solved by the present invention is to provide a safety detection device of passenger conveying equipment, which can detect overspeed and inversion of the passenger conveying equipment and cover fault causes within more extensive scope. For this, this application further has to provide a method of implementing the safety detection device.

Technical solution

In solving the above technical problem, a device according to independent claim 1 and a method according to independent claim 6 are proposed. Advantageous modifications are proposed in the dependent claims.

Beneficial results

With the safety detection device of passenger conveying equipment of this application and the implementation method thereof, marks distributed across 360 degrees are provided on at least one of the low-speed rotary parts, thus covering the output faults of the drive device, the broken drive chain, the abnormal displacement of the drive chain, and other faults. In order to deal with the normal shake and vibration of each part of the passenger conveying equipment in operation, this application adopts non-contact optical detection means, thus improving its reliability and operation stability significantly.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a structural schematic view of the passenger conveying equipment in principle;
Fig. 1a is a partial enlarged schematic view of each part in Fig. 1 rotating coaxially with the spindle;
Fig. 2 is a schematic view of Example 1 of the safety detection device of passenger conveying equipment of this application;
Figs. 2a-2d are a deformed schematic view of Fig. 2, representing different kinds of marks and the combination thereof, respectively; and
Fig. 3 is a flowchart of Example 1 of the method of implementing the safety detection device of passenger conveying equipment of this application.

List of reference numbers: 1. Drive device; 11. motor; 12. reduction box; 2. spindle; 21. cylinder or spiral cylinder; 22, 22a, 22b, 22c. mark; 31. output sprocket; 32. drive sprocket; 33. drive chain; 41. first step sprocket; 42. second step sprocket; 43. step chain; 44. step; 51. first handrail sprocket; 52. second handrail sprocket; 53. handrail chain; 54. handrail; and 9, 9a, 9b, 9c. optical sensor.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 2 shows Example 1 of the safety detection device of passenger conveying equipment of this application. The passenger conveying equipment is as shown in Fig. 1. In the safety detection device, the spindle 2 is provided with a cylinder 21, which rotates coaxially with the spindle 2. Mark 22 is provided on the tubular outside of cylinder 21, and mark 22 is distributed annularly across 360 degrees on the tubular outside of the cylinder 21 to represent the different rotation angle of this cylinder 21. The optical sensor 9 is separated from both the spindle 2 and the cylinder 21 by a certain distance, at least over 5 mm, preferably over 10 mm, so as to avoid damage caused by the normal shake and vibration of the spindle 2, the cylinder 21 and the like while in movement. The optical sensor 9 is disposed in such a position that the optical sensor 9 can both detect at least a part of the tubular outside of the cylinder 21 in real time, and clearly recognize at least one kind of the marks 22 thereon.
Alternatively, the mark 22 is distributed annularly across 360 degrees on the annular bottom of the cylinder 21, as shown in Fig. 2a. Alternatively, the mark 22 can also be distributed annularly across 360 degrees on the tubular outside or annular bottom of the spindle 2, the drive sprocket 32, the first step sprocket 41, the second step sprocket 42, the first handrail sprocket 51, the second handrail sprocket 52, or a part rotating coaxially with any of them, and can also be distributed annularly across 360 degrees on the tubular outside, tubular inside or annular bottom of the drive chain 33, the step chain 43, and the handrail chain 53.
The mark 22 is for example a two-dimensional code pattern, as shown in Figs. 2 and 2a. Here the optical sensor 9 is photography equipment. Taking a cylinder 21 having a diameter of 200 mm as an example, the perimeter of its annular side is about 628 mm. In consideration of the detection precision of the optical sensor 9, setting a single width of the mark 22 to be 0.5 mm, the number of the mark 22 will be 1256 in total. This is equivalent to that, across the range of 360 degrees, there is a different mark 22 every 0.2866 degree to represent the rotation angle of the cylinder 21. Each of the marks 22 of the two-dimensional code pattern, for example, corresponds to a 20-bit binary code, wherein 12 bits are used to mark the actual rotation angle, and 8 bits are used for the CRC verification and correction. When the pattern is partially not clear, the probability of successful reading of the optical sensor 9 can be improved through the CRC correction function.

In addition to the two-dimensional code patterns shown in Figs. 2 and 2a, the mark 22 can also be in the form of color, so long as the low-speed rotary parts where the mark 22 is located rotate across the range of 360 degrees, with each mark represented by a different color. For example, a cylinder is evenly divided into 360 sectors by 1 degree, each of the sectors being provided on the surface and bottom thereof with colors different from one another. Such a tubular surface and annular bottom is formed on any of the low-speed rotary parts, and thus colors, as a mark 22, allow identification of the rotation angle by the photography equipment 9 at a resolution of 1 degree.
The mark 22 can also form a spiral surface on the outside of any of the low-speed rotary parts. As shown in Fig. 2b, the spindle 2, for example, is provided with a spiral cylinder 21 that has a spiral outside and rotates coaxially therewith. All the spiral surfaces are characterized by a gradual distance from the axis of the structure where they are located across the annular range of 360 degrees, and are then used as a mark 22. Here the optical sensor 9, e.g. a laser or an infrared-light distance-measuring device, is a distance-measuring device spaced at a distance away from the low-speed rotary parts where the mark 22 is located. Because the distance between this mark 22 and the fixedly disposed optical sensor 9 is also different from one another across the range of 360 degrees of rotation of the low-speed rotary parts where the mark 22 is located, the optical distance-measuring device 9 obtains the current rotation angle of the low-speed rotary parts where the mark 22 is located by measuring the distance to the mark 22.
In addition to the spiral surface shown in Fig. 2b, the mark 22 can also have other stereoscopic structure, so long as the distance between the stereoscopic structure and the optical sensor is different from one another across the range of 360 degrees of rotation of the low-speed rotary parts where the stereoscopic structure is located. For example, a cylinder is evenly divided into 3600 sectors by 0.1 degree, making the distance between each surface of the sector and the axis different from one another by blocking up or chamfering. With such a tubular surface formed on the outer surface of any of the low-speed rotary parts, this stereoscopic structure is used as a mark 22 and allows identification of the rotation angle by the optical distance-measuring device 9 at a resolution of 0.1 degree.
The mark 22 in the form of a two-dimensional code pattern, color and stereoscopic structure can be use separately or in combination.
As shown in Fig. 2c, two different marks 22 and two different optical sensors 9 are used. The first mark 22a is a stereoscopic structure -- the outside of the spiral surface of the spiral cylinder 21, and the corresponding first optical sensor 9a is an optical distance-measuring device. The second mark 22b is the color on the annular bottom of the spiral cylinder 21, and the corresponding second optical sensor 9b is photography equipment. Each of the optical sensors 9 is disposed in such a position that the optical sensor 9 can detect and clearly recognize in real-time at least one kind of the marks 22 of the corresponding kind.
As shown in Fig. 2d, three different marks 22 and two different optical sensors 9 are used. The first mark 22a is a two-dimensional code pattern on the outer surface of the spiral cylinder 21, and one of the corresponding first optical sensors 9a is photography equipment. The second mark 22b is a stereoscopic structure -- the outside of a spiral surface of the spiral cylinder 21, and the corresponding second optical sensor 9b is an optical distance-measuring device. The third mark 22c is the color on the annular bottom of the spiral cylinder 21, and a second of the corresponding first optical sensors 9c is photography equipment. Each of the optical sensors 9 is disposed in such a position that the optical sensor 9 can real-time detect and clearly recognize at least one kind of the marks 22 of the corresponding kind.
As shown in Fig. 3, Example 1 of the method of implementing the safety detection device of passenger conveying equipment of this application is as follows:

First, the optical sensor detects the low-speed rotary parts with marks distributed across 360 degrees, with the detection including photography and distance measurement. Therefore, the current rotation angle of the low-speed rotary parts can be known. Preferably, this detection is carried out at a regular interval such as 5 ms. Taking Fig. 2 as an example, for facilitating description, a certain position is defined as 0°, and then the value range of the current rotation angle θ of this low-speed rotary part is 0° ≤ θ <360°.
Second, with the two rotation angles θ1 and θ2 of the low-speed rotary parts with marks distributed across 360 degrees being detected by the optical sensor at at least two different times t1 and t2, the controller connected with the optical sensor can calculate the rotary angular speed ω of the low-speed rotary parts between these two times.

Preferably, these two different times t1 and t2 are adjacent times, i.e. the interval between the two times is the detection period of the optical sensor, e.g. 5 ms. The rotation angle of this low-speed rotary part in such a short interval is far less than 360°. Therefore, when the mark representing the 0° position is not detected by the optical sensor between these two times t1 and t2, ω = |θ 2 - θ 11/(t2 -11); when the mark representing the 0° position is detected by the optical sensor between these two times t1 and t2, ω = [360° -| θ 2 - θ 1|]/(t2 -t1).
Third, the controller converts the angular speed and movement direction of the low-speed rotary parts with marks distributed across 360 degrees into the step movement speed and step movement direction of the passenger conveying equipment, respectively.
Assuming that the low-speed rotary part with marks distributed across 360 degrees is the spindle 2 or a part rotating coaxially with the spindle 2, the movement speed of the step chain 43 between these two times t1 and t2 is V= ωd, wherein d is the diameter of the first step sprocket 41, and V is then the step movement speed of the steps 44 between these two times. If the marked low-speed rotary part distributed across 360 degrees is another part, its angular speed can also be converted into the angular speed of the spindle 2.
There is a fixed correspondence relation between the movement direction of the low-speed rotary parts with marks distributed across 360 degrees and the step movement direction, and thus the conversion is very easy to be done. Taking Fig. 2 as an example, the rotary direction of the cylinder 21 from 0° to 360°, for example, is the upstream direction of the steps 44, and the rotary direction of the cylinder 21 from 360° to 0° is the downstream direction of the steps 44, with the step direction instruction obtained by the controller from the main controller of the escalator being the upstream direction. Therefore, when the two rotation angles of the cylinder 21 detected by the controller at the two different times t1 and t2 are 25° and 30°, respectively, the steps 44 are judged to move in the upstream direction. Once the two rotation angles of the cylinder 21 detected by the controller at the two different times t1 and t2 are 15° and 355°, respectively, the steps 44 are judged to move in the downstream direction.
Finally, the controller judges whether the movement direction of the steps 44 keeps consistent with the direction instruction, and whether the movement speed of the steps 44 falls into the normal range of the movement speed. If the movement direction of the steps 44 undergoes non-manipulation inversion or the movement speed of the steps 44 goes beyond the upper limit of the normal movement speed, the controller will judge that the passenger conveying equipment undergoes inversion or speeding movement, and thus stop operation of the passenger conveying equipment.
According to the invention, the controller of the safety detection device is additionally configured to execute the steps laid out in the following three points:

First, the controller determines whether the absolute value of the difference between the two rotation angles θ1 and θ2 of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times t1 and t2 is greater than the first preset value. If the first preset value is less, it is indicated that the rotation angle θ2 detected at the recent time t2 has an error, and thus this rotation angle θ2 is abandoned and meanwhile this error is recorded. The first preset value should be greater than the rotation angle of this low-speed rotary part into which the product of the detection period of the optical sensor 9 and the upper limit of the normal movement speed of the steps 44 is converted, which is set to be 30° for example.
Second, the controller determines whether the absolute value of the difference between the two rotation angles θ1 and θ2 of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times t1 and t2 is less than the second preset value. If the second preset value is greater, it is indicated that the rotation angle θ2 detected at the recent time t2 has an error, and thus this rotation angle θ2 is abandoned and meanwhile this error is recorded. The second preset value should be less than the rotation angle of this low-speed rotary part into which the product of the detection period of the optical sensor 9 and the lower limit of the normal movement speed of the steps 44 is converted.
Third, the controller analyses the mistakes detected by the optical sensor 9 in statistics and, once the number of mistakes is greater than the threshold, judges that the optical sensor 9 is abnormal or the mark 22 needs to be cleaned. The controller will stop operation of the passenger conveying equipment, and sends the fault code to remind maintenance personnel for maintenance.

A handrail speed sensor is added in Example 2 of the safety detection device of passenger conveying equipment of this application based on the invention. The handrail speed sensor is used for detecting the handrail speed of the passenger conveying equipment. For example, the rotary speed of a friction wheel of the handrail is detected by a magnetic proximity or photoelectric sensor. Whenever the friction wheel of the handrail rotates by a regular angle, the handrail speed sensor detects and outputs one handrail pulse signal. The controller, according to the handrail pulse signal received every time, can calculate the movement speed of the handrail.

Example 2 of the method of implementing the corresponding safety detection device of passenger conveying equipment is as follows: When the safety detection device includes the handrail speed sensor, the controller calculates the handrail movement speed of the passenger conveying equipment according to the handrail speed sensor. When the deviation of the step movement speed from the handrail movement speed is less than a certain threshold, the controller will judge that the handrail movement speed is normal. When the step movement speed is greater than the handrail movement speed with the difference greater than this threshold, the controller will judge that the speed of the handrail is under the required speed. When the step movement speed is less than the handrail movement speed with the difference greater than this threshold, the controller will judge that the speed of the handrail is over the required speed.
Once the speed of the handrail is under or over the required speed and this keeps for a period of time (e.g. 15 s), the controller will stop operation of the passenger conveying equipment for protection.
A step sensor is added in Example 3 of the safety detection device of passenger conveying equipment of this application based on the invention. With the step sensor being for example a magnetic proximity or photoelectric sensor, when any step enters the detection range of the step sensor, the sensor will send out a step pulse signal. If a step or footrest is missing, the step pulse signal appearing with a regular period will be missing.
Example 3 of the method of implementing the corresponding safety detection device of passenger conveying equipment is as follows: When the safety detection device includes the step sensor, the controller can calculate the time interval of the adjacent step pulse signals according to the step movement speed. After the controller receives one step pulse signal, if the step pulse signal of the step sensor is not detected at the time node (allowing to set a certain time range) when the next step pulse signal is predicted to be received, the controller will judge that the passenger conveying equipment has a missing step, and thus stop operation of the passenger conveying equipment.
When the optical sensor 9 is photography equipment, it can also detect the shake condition of the low-speed rotary parts distributed across 360 degrees in addition to detection of the mark 22 in the form of the two-dimensional code and color. For example, if the optical sensor 9 is mounted in alignment with the center of the respective marks 22, the controller, through identification of the edge of the respective marks 22, can immediately obtain the axial and radial shake amplitude of the low-speed rotary parts where these marks 22 are located at the current time. When the controller finds that the shake amplitude of the low-speed rotary parts where these marks 22 are located is greater than the preset threshold, it will stop operation of the passenger conveying equipment.
For the marks 22 of the same kind, two or more optical sensors 9 can also be provided at a certain distance away from each other. By comparing the order and time difference at which the same marks 22 are detected by these two optical sensors 9, the controller can obtain the rotary direction and rotary angular speed of the low-speed rotary parts where the marks 22 are located, and converts the results into the step movement direction and step movement speed of the passenger conveying equipment.
The controller will stop operation of the passenger conveying equipment, and can cut off the safety relay in the controller to cut off the safety loop; by braking the main controller of the escalator through the safety communication bus, the operation of the passenger conveying equipment can also be stopped.
The scope of protection of this application is defined by the appended claims.

Claims

A passenger conveying equipment, comprising:
low-speed rotary parts selected from the group comprising: a spindle, a drive sprocket, a drive chain, a first step sprocket, a second step sprocket, a step chain, a first handrail sprocket, a second handrail sprocket, a handrail chain, or a part rotating coaxially with any of the above parts;

the passenger conveying equipment further comprising, a safety detection device comprising:
- one or more kinds of marks provided on any of the low-speed rotary parts, and wherein at least one kind of the marks or a combination/combinations of various marks are distributed across 360 degrees on a tubular side or an annular bottom of at least one of the low-speed rotary parts, representing different rotation angles of the low-speed rotary parts with marks distributed across 360 degrees;

- at least one sensor isolated from the low-speed rotary parts and used for identifying the marks; and

- a controller connected with the sensor for calculating step movement direction and step movement speed of the passenger conveying equipment according to rotation angles and change direction of rotation angle of the low-speed rotary parts with the mark or marks identified by the sensor at different times, comparing the above results with step direction instruction and step speed instruction from a main controller of the escalator, and stopping movement of the passenger conveying equipment when step inversion or speeding movement is detected,

the controller determines whether the absolute value of the difference between the two rotation angles of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times is greater than the first preset value; if the first preset value is less, it is indicated that the rotation angle detected at the recent time has a mistake, and thus this rotation angle is abandoned and meanwhile this mistake is recorded; the first preset value is greater than the rotation angle of this low-speed rotary part with marks distributed across 360 degrees into which the product of the detection period of the sensor and the upper limit of the normal movement speed of the step is converted;

characterised in that

the sensor is an optical sensor and in that

the controller also determines whether the absolute value of the difference between the two rotation angles of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times is less than the second preset value; if the second preset value is greater, it is indicated that the rotation angle detected at the recent time has a mistake, and thus this rotation angle is abandoned and meanwhile this mistake is recorded; the second preset value is less than the rotation angle of this low-speed rotary part with marks distributed across 360 degrees into which the product of the detection period of the sensor and the lower limit of the normal movement speed of the step is converted; and

the controller analyses the mistakes detected by the optical sensor in statistic and, once the number of mistakes is greater than the threshold, judges that the sensor is abnormal or the mark needs to be cleaned; the controller will stop operation of the passenger conveying equipment, and reports the fault code to remind maintenance personnel for maintenance.
The passenger conveying equipment according to claim 1, characterized in that:
the mark is a two-dimensional code pattern, a color, a stereoscopic structure or any combination thereof, and the optical sensor is photography equipment, an optical distance-measuring device or any combination thereof;

when the mark includes the two-dimensional code pattern or color, the optical sensor includes at least the photography equipment; and

when the mark includes the stereoscopic structure, the optical sensor includes at least the optical distance-measuring device.
The passenger conveying equipment according to claim 1, characterized in that: the optical sensor is at a distance over 5 mm away from the low-speed rotary parts with marks distributed across 360 degrees.
The passenger conveying equipment according to claim 1, characterized in that: it further includes a handrail speed sensor used for detecting handrail movement speed of the passenger conveying equipment; and
the controller gets the handrail movement speed of the passenger conveying equipment according to the handrail speed sensor, compares the results with the step movement speed, and stops movement of the passenger conveying equipment when an absolute value of deviation of the handrail movement speed from the step movement speed is greater than a threshold.
The passenger conveying equipment according to claim 1, characterized in that: it further includes a step sensor that sends out a step pulse signal when any step is detected; and
the controller will stop operation of the passenger conveying equipment if the step pulse signal of the step sensor is not detected when the step pulse signal is predicted to be received according to the step movement speed.
A method of implementing a safety detection device for a passenger conveying equipment, characterized in that:
first, a sensor, through detection of marks, obtains the current rotation angle of low-speed rotary parts with the marks distributed across 360 degrees;

second, according to the rotation angle of the low-speed rotary parts detected by the sensor at different times, a controller calculates the angular speed and obtains the movement direction thereof;

third, the controller converts the angular speed and movement direction of the low-speed rotary parts into the step movement speed and step movement direction of the passenger conveying equipment, respectively, and compares the above results with the step speed instruction and step direction instruction from the main controller of the escalator; and

finally, when the step speeding or inversion is detected, the controller stops movement of the passenger conveying equipment, the controller determines whether the absolute value of the difference between the two rotation angles of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times is greater than the first preset value; if the first preset value is less, it is indicated that the rotation angle detected at the recent time has a mistake, and thus this rotation angle is abandoned and meanwhile this mistake is recorded; the first preset value is greater than the rotation angle of this low-speed rotary part with marks distributed across 360 degrees into which the product of the detection period of the sensor and the upper limit of the normal movement speed of the step is converted;

characterised in that

the sensor is an optical sensor and in that

the controller also determines whether the absolute value of the difference between the two rotation angles of the low-speed rotary parts with marks distributed across 360 degrees detected at two adjacent times is less than the second preset value; if the second preset value is greater, it is indicated that the rotation angle detected at the recent time has a mistake, and thus this rotation angle is abandoned and meanwhile this mistake is recorded; the second preset value is less than the rotation angle of this low-speed rotary part with marks distributed across 360 degrees into which the product of the detection period of the sensor and the lower limit of the normal movement speed of the step is converted; and

the controller analyses the mistakes detected by the optical sensor in statistic and, once the number of mistakes is greater than the threshold, judges that the sensor is abnormal or the mark needs to be cleaned; the controller will stop operation of the passenger conveying equipment, and reports the fault code to remind maintenance personnel for maintenance.
The method of implementing the safety detection device for a passenger conveying equipment according to claim 6, characterized in that: when the optical sensor is photography equipment, the shake condition of the low-speed rotary parts distributed across 360 degrees is also detected; when the controller finds that the shake amplitude of the low-speed rotary parts with marks distributed across 360 degrees is greater than the preset threshold, it will stop operation of the passenger conveying equipment.
The method of implementing the safety detection device for a passenger conveying equipment according to claim 6, characterized in that: when the safety detection device includes the handrail speed sensor, the controller gets the handrail movement speed of the passenger conveying equipment according to the handrail speed sensor, compares the results with the step movement speed, and stops movement of the passenger conveying equipment when the absolute value of deviation between them is greater than the threshold.
The method of implementing the safety detection device for a passenger conveying equipment according to claim 6, characterized in that: when the safety detection device includes the step sensor, the controller will stop operation of the passenger conveying equipment if the step pulse signal of the step sensor is not detected when the step pulse signal is predicted to be received according to the step movement speed.