Optoelectronic speed sensor, elevator operating speed control device and method

Abstract

The application relates to an optical-electric speed measuring sensor, an elevator running speed control device and a method, and belongs to the field of elevator running speed control. First, a pulse signal of a speed measuring sensor is acquired, the pulse signal is input into a signal maintaining and shaping circuit for processing, a signal processed by the signal maintaining and shaping circuit is input into a single-chip microcomputer for processing, a logic pulse width corresponding time and a standard high-frequency clock pulse number are obtained, the speed of a steel wire rope is calculated based on the logic pulse width corresponding time and the standard high-frequency clock pulse number, the running speed of an elevator car is calculated based on the speed of the steel wire rope, the running speed of the elevator car is compared with a preset speed, a control instruction is sent to a motor frequency converter according to a comparison result, and the running speed of the elevator car is adjusted. The method can realize higher displacement and speed measurement precision with low resolution coding values.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of elevator running speed control, in particular to an optical speed sensor, an elevator running speed control device and method. BACKGROUND

[0002] With the development of high-rise buildings, elevator operation state monitoring is becoming more and more important. In the aspect of elevator operation, people pay more attention to the safety and comfort of elevator operation. The up and down running speed of the car is monitored by the speed governor in real time. Once the car is out of control and overspeed, the speed governor will start the safety gear to stop the car on the guide rail immediately. The running speed of the elevator car not only relates to the comfort of passengers, but also involves the personal safety of passengers. Therefore, it is very important to control the running speed of the elevator.

[0003] In the elevator electromechanical system, one end of the traction steel wire rope is fixedly installed in the elevator car, and the other end is fixedly installed in the elevator system counterweight. When the motor in the elevator system operates, the roller is also rotated, and the friction pad on the outer edge of the roller will generate friction with the steel wire rope. The friction force is used to make the steel wire rope traction car movement to realize the lifting and lowering action of the car. Therefore, detecting the running speed of the steel wire rope can obtain the running speed of the elevator car. The traction steel wire rope is one of the important safety components of the elevator equipment, which needs to be able to carry the total sum of the elevator and the internal personnel and the suspended mass. The steel wire rope bears a large tension in the work of the elevator equipment. When the elevator equipment works normally, the tension of the steel wire rope should not exceed its rated load. If the tension of the steel wire rope exceeds its rated load for a long time, the steel wire rope will be damaged or even broken. The safety of the steel wire rope work will directly affect the operation of the elevator and the safety of the passengers. Therefore, it is very important to detect the tension change of the steel wire rope in real time.

[0004] In the field of elevator car speed monitoring, common methods for elevator car speed detection include: ① using incremental encoders to measure elevator car speed; ② using absolute encoders to obtain car speed. The first method, using incremental encoders to measure elevator car speed, indirectly obtains the elevator car's speed signal by measuring the relative distance traveled by the incremental encoder installed on the traction sheave. The elevator car's position is then calculated, and the controller adjusts the traction motor speed after determining the car's position. However, this method is prone to losing accurate car position due to slippage between the traction sheave and the wire rope. Furthermore, interference causing pulse loss in the incremental encoder also leads to a loss of accurate car position. Therefore, the accuracy of car position measurement is not high. It cannot solve the interference factors present in practical applications, resulting in a low-speed crawling section during the car's braking phase, leading to poor passenger comfort. The second method uses an absolute encoder to control the car's speed. This method employs an absolute encoder, which is fixedly installed on the top of the car and moves synchronously with it. The encoder's reading head directly obtains the car's absolute position signal by reading the encoded value from the coded steel strip installed in the elevator shaft. After determining the car's position, the controller adjusts the traction motor speed according to the ideal elevator speed curve. This method offers high accuracy in car position measurement, but it also has high equipment costs. The encoder device needs to be installed in the elevator shaft, making the installation complex and increasing maintenance costs.

[0005] In summary, existing low-frequency traction speed monitoring devices all have the following problems in practical use: ① Incremental encoders for measuring elevator car speed are prone to pulse loss, resulting in low accuracy in car position and speed measurement. Therefore, speed control during car braking is not ideal, leading to poor ride comfort; ② Absolute encoders for obtaining car speed control are costly, requiring installation of the encoder in the elevator shaft, making installation complex and maintenance costs high. Summary of the Invention

[0006] The purpose of this invention is to provide a photoelectric speed sensor, an elevator running speed control device and method, which achieves high displacement and speed measurement accuracy with low-resolution encoded values.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A photoelectric speed sensor, comprising: an outer steel ring, a ball bearing, an inner steel ring, a photoelectric switch assembly, and a mounting hole;

[0009] The balls are disposed between the outer steel ring and the inner steel ring to form a ball bearing structure;

[0010] The photoelectric switch assembly is located on the inner side of the inner steel ring;

[0011] The mounting hole is formed on the inner steel ring for mounting and fixing the speed sensor; the mounting hole is coaxial with the inner steel ring.

[0012] The outer surface of the outer steel ring is provided with a groove; the steel wire rope is wound inside the groove.

[0013] The inner rim of the outer steel ring is machined with concave and convex teeth of varying lengths; when the outer steel ring rotates, the infrared light emitted by the photoelectric switch group irradiates the concave or convex teeth to form light pulses of different intensities.

[0014] Optionally, the groove is V-shaped.

[0015] Optionally, the speed sensor further includes a seal for encapsulating the speed sensor.

[0016] Optionally, the photoelectric switch group includes: a first photoelectric switch, a second photoelectric switch, and a third photoelectric switch, wherein the first photoelectric switch, the second photoelectric switch, and the third photoelectric switch are evenly arranged on the inner side of the inner steel ring;

[0017] The first photoelectric switch, the second photoelectric switch, and the third photoelectric switch are all reflective infrared proximity tube photoelectric switches.

[0018] Based on the sensor described above in this invention, this invention further provides an elevator running speed control device, the control device comprising the aforementioned photoelectric speed sensor, the control device including:

[0019] Wire rope, first hoisting container, first hoisting wheel, rollers, photoelectric speed sensor, second hoisting wheel, second hoisting container, speed monitoring and control system;

[0020] One end of the wire rope is connected to the first lifting container and passes sequentially around the first top sheave, roller, speed sensor and second top sheave; the other end of the wire rope is connected to the second lifting container.

[0021] The photoelectric speed sensor is connected to the speed monitoring and control system.

[0022] Optionally, the control device further includes an elevator control room, wherein the speed sensor and the speed monitoring and control system are located in the elevator control room.

[0023] Optionally, the speed measurement and monitoring control system includes:

[0024] Signal holding and shaping circuit, microcontroller, and display;

[0025] The input terminal of the signal holding and shaping circuit is connected to the speed sensor, and the signal holding and shaping circuit is used to transform the output level of the speed sensor into a processing level suitable for the microcontroller system.

[0026] The input terminal of the microcontroller is connected to the output terminal of the signal holding and shaping circuit, and the output terminal of the microcontroller is connected to the display. The microcontroller is used to acquire the output encoded value of the signal holding and shaping circuit.

[0027] The microcontroller is also used to process the encoded value to obtain the logic pulse width corresponding time and the number of standard high-frequency clock pulses.

[0028] Based on the above-described apparatus of the present invention, the present invention further provides an elevator running speed control method, wherein the control method is applied to the above-described control apparatus, and the control method includes:

[0029] Acquire the pulse signal from the photoelectric speed sensor;

[0030] The pulse signal is input to a signal holding and shaping circuit for processing.

[0031] The signal processed by the signal holding and shaping circuit is input to the microcontroller for processing to obtain the logic pulse width corresponding time and the number of standard high-frequency clock pulses.

[0032] The speed of the wire rope is calculated based on the corresponding time of the logic pulse width and the number of standard high-frequency clock pulses.

[0033] The elevator car speed is calculated based on the speed of the steel wire rope.

[0034] The elevator car's operating speed is compared with a preset speed;

[0035] Based on the comparison results, control commands are sent to the motor inverter to adjust the elevator car's running speed.

[0036] Optionally, the control method further includes, after "sending control commands to the motor inverter based on the comparison results to adjust the elevator car speed":

[0037] The current position of the elevator car is determined based on the elevator car's operating speed.

[0038] Optionally, the speed of the wire rope is calculated based on the time corresponding to the logic pulse width and the number of standard high-frequency clock pulses using the following formula:

[0039]

[0040] Where L is the circumference of the outer steel ring, F is the standard high-frequency clock frequency, and M... kThis represents the standard high-frequency clock pulse count.

[0041] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0042] This invention proposes a photoelectric speed sensor, an elevator running speed control device and method. The control device includes a speed sensor and a speed monitoring and control device. Compared with incremental encoders, which are prone to pulse loss when measuring the speed of the elevator car and lose current position information after system power failure, resulting in low accuracy of car position and speed measurement, the speed monitoring and control device of this invention can locate the current position of the elevator car by software by observing the encoded value of the speed sensor at four consecutive time points after power failure and restart.

[0043] Compared to absolute encoders, which are expensive, complex to install, and have high maintenance costs, the speed sensor of this invention has no special requirements for its installation position relative to the elevator traction motor. It only requires the speed sensor to contact the wire rope and ensure that the outer steel ring of the speed sensor moves synchronously with the wire rope. Therefore, it is easy to install and use, and has low maintenance costs.

[0044] The measurement accuracy of the speed sensor of this invention depends on the minimum resolvable unit arc length. The standard clock frequency F MHz is generated internally by the microcontroller. Increasing the value of the standard clock frequency F can further improve the speed measurement accuracy. The standard clock frequency F generated internally by the microcontroller can also be increased by modifying the monitoring system software. Therefore, this invention proposes an elevator speed control device and method based on a photoelectric speed sensor, which can achieve higher speed measurement accuracy at a lower cost. A special rotational encoding method can obtain higher displacement and speed measurement accuracy (equivalent to 6-bit absolute encoding value) with low-resolution (3-bit encoding value) absolute value encoding. The special structural design effectively reduces the processing technology and accuracy requirements, thereby reducing the cost of the sensor. Therefore, the speed sensor of this invention can effectively reduce equipment costs, has high speed measurement accuracy, and low use and maintenance costs.

[0045] This invention designs a low-frequency traction system speed sensor and a speed measurement method and device based on the sensor. The sensor's special rotational encoding method can obtain high displacement and velocity measurement accuracy (equivalent to 6-bit absolute encoding value) with low-resolution (3-bit encoding value) absolute value encoding. The special structural design effectively reduces the processing technology and accuracy requirements, thereby reducing the cost of the sensor.

[0046] In summary, the photoelectric speed sensor, elevator speed control device, and method proposed in this invention offer high accuracy in speed and position measurement, and are easy to use, install, and maintain. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the speed sensor structure according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of the internal structure of the speed sensor according to an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the elevator speed control device based on a photoelectric speed sensor according to an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the inner rim tooth structure of the outer steel ring according to an embodiment of the present invention;

[0052] Figure 5 This is a timing diagram of the clockwise rotation pulse of the speed sensor according to an embodiment of the present invention;

[0053] Figure 6 This is a block diagram of the processing circuit of the speed monitoring device according to an embodiment of the present invention.

[0054] Symbol explanation:

[0055] First lifting container - 1; Wire rope - 2; First sheave - 3; Roller - 4; Second sheave - 5; Second lifting container - 6; Elevator control room - 7; Speed ​​sensor - 8; Speed ​​monitoring and control system - 9; Connecting wire - 10; Outer steel ring - 801; Ball bearing - 802; Inner steel ring - 803; Photoelectric switch assembly - 804; Assembly hole - 805; Seal - 806. Detailed Implementation

[0056] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] The purpose of this invention is to provide a photoelectric speed sensor, an elevator running speed control device and method, which achieves high displacement and speed measurement accuracy with low-resolution encoded values.

[0058] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Figure 1 This is a schematic diagram of the speed sensor structure according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the internal structure of the speed sensor according to an embodiment of the present invention, as shown below. Figure 1 and Figure 2 As shown, the sensor in this invention includes:

[0060] Outer steel ring 801, ball bearing 802, inner steel ring 803, photoelectric switch assembly 804, mounting hole 805, and seal 806;

[0061] The ball 802 is a cylindrical ball, which is disposed between the outer steel ring 801 and the inner steel ring 803 to form a ball bearing structure.

[0062] The photoelectric switch group 804 specifically includes: a first reflective infrared proximity photoelectric switch, a second reflective infrared proximity photoelectric switch, and a third reflective infrared proximity photoelectric switch. The three reflective infrared proximity photoelectric switches 804 are named LR1, LR2, and LR3 respectively. The included angle between each pair of LR1, LR2, and LR3 is θ3, where θ3 = 120° (that is, LR1, LR2, and LR3 are evenly distributed on the circumference of the inner steel ring 803).

[0063] The main function of seal 806 is to protect the inside of the speed sensor from corrosion and contamination, ensuring the speed sensor operates under good conditions. To accurately explain the internal structure of the speed sensor, seal 806 will be removed, and the internal structure of the speed sensor 8 will be described below, as follows: Figure 2 As shown, the inner steel ring 803 has an inner steel ring mounting hole 805 machined on it. The mounting hole 805 is used to install and fix the speed sensor 8. For example, when there are multiple speed sensors, the multiple speed sensors are coaxially assembled together through the mounting hole 805. After assembly, the inner steel ring 803 is fixed and does not rotate.

[0064] The outer surface of the outer steel ring 801 is provided with a groove; the steel wire rope 2 is wound in the groove. Preferably, the groove in the present invention can be V-shaped or other shapes. The linear movement of the steel wire rope 2 drives the outer steel ring 801 to rotate (the outer steel ring 801 rotates relative to the inner steel ring 803).

[0065] The inner rim of the outer steel ring 801 is machined with concave and convex teeth of varying lengths; when the outer steel ring rotates, the infrared light emitted by the photoelectric switch assembly illuminates the concave or convex teeth, forming light pulses of varying intensities, as shown in the structure. Figure 4As shown, the diameter of the outer steel ring 801 is D, and the circumference of the outer steel ring 801 is L (L=πD). In the diagram, the radian angles of the concave tooth CC1 and the convex tooth CG1 are both θ2, and the radian angle of the concave tooth CC2 is 2θ2. The design is 4θ2=90°, therefore θ2=22.5°. Thus, the arc length of the concave tooth CC1 is... The arc length of the convex tooth CG1 is The arc length of the concave tooth CC2 is Similarly, the arc length of CC3 is The arc length of the convex tooth CG3 is The arc length of the concave tooth CC4 is In the diagram, the radian angle of the protruding tooth CG4 is θ1, where θ1 = 90°. Therefore, the arc length of the protruding tooth CG4 is... Similarly, the arc length of the convex tooth CG2 is

[0066] The working principle of the speed sensor is as follows:

[0067] The traction wire rope 2 is wound inside the V-groove of the speed sensor 8, and each wire rope is equipped with one speed sensor 8. Figure 3 Four steel wire ropes are used, so four speed sensors 8 are coaxially mounted. The speed sensors 8 are installed between the roller 4 and the second roller 5. There are no special requirements for the installation position. The speed sensors 8 are in close contact with the steel wire rope 2. Figure 3 The speed sensor 8 uses a bypass contact steel wire rope, which is convenient for installation. Four speed sensors 8 are coaxially mounted and operate in the same way. We will now analyze the working process of one of them. When the steel wire rope 2 is wound in the V-groove of the speed sensor 8, the traction steel wire rope is inserted into and contacts the outer steel ring 801 through the V-groove. The linear movement of the steel wire rope drives the outer steel ring 801 to rotate (the outer steel ring 801 rotates relative to the inner steel ring 803). The inner steel ring 803 is fixedly equipped with three reflective infrared proximity photoelectric switches 804. The inner rim of the outer steel ring 801 is machined with concave and convex teeth of varying lengths. During the rotation of the outer steel ring 801, the infrared light emitted by the reflective infrared proximity photoelectric switches 804 illuminates the concave or convex teeth on the inner rim of the outer steel ring 801, forming light pulses of different intensities. These light pulses are processed and shaped into a standard 5V TTL logic level for use by the subsequent speed monitoring and control device 9. We will now analyze the working process of one of them. Figure 2 A schematic diagram of the internal structure of the speed sensor, using the clockwise rotation of the outer steel ring 801 as an example, is shown below. Figure 2 As shown at this moment T kAt any given moment, the reflective infrared proximity photoelectric switch 804LR1 is positioned at the concave tooth CC1 on the inner rim of the outer steel ring 801. At this time, the infrared light emitted by LR1 illuminates the concave tooth CC1 and is reflected back to LR1. Due to the larger distance between LR1 and the concave tooth CC1 (compared to the convex tooth), the light received by LR1 is weak and is processed and shaped into a logic low level (hereafter represented by "0"). The outer steel ring 801 rotates clockwise. At the next moment T... k+1 The reflective infrared proximity photoelectric switch 804LR1 is positioned relative to the inner rim protrusion CG4 of the outer steel ring 801. At this time, the infrared light emitted by LR1 illuminates the protrusion CG4 and is reflected back to LR1. Due to the small distance between LR1 and the protrusion CG4, the received light intensity is high. After processing, it is shaped into a logic high level (hereafter represented by "1"). Similarly, T can be obtained. k The logic signals received by LR2 and LR3 at time T are "1" and "0" respectively. k+1 At time LR2 and LR3, the received logic signals are "1" and "0" respectively. Based on the above analysis, T... k The logic signals received by LR1, LR2, and LR3 at time T are represented as (010). k+1 The logic signals received at times LR1, LR2, and LR3 are represented as (110). Since the minimum arc length of the concave and convex teeth on the inner rim of the 801 outer steel ring is... The 803 inner steel ring is fixedly equipped with three 804 reflective infrared proximity photoelectric switches, therefore the minimum logic pulse width unit With T k At the start of each step (LR1, LR2, LR3), the outer steel ring 801 rotates clockwise, recording the timing diagram of the received level pulses for LR1, LR2, and LR3. The timing diagram for one full clockwise rotation of the outer steel ring 801 is shown below. Figure 5 As shown in the figure. A minimum logic pulse width unit. The corresponding time is T (T = T) k+1 -T k That is, the next time T k+1 With the current time T k (Time difference), the diagram uses 1, 2, 3...48 to represent the time sequence of one clockwise rotation of the outer steel ring 801, according to... Figure 5 The timing diagram shows that the output codes of LR1, LR2, and LR3 from time 1 to time 48 are (111), (111), (101), (101), (100)...(011). Following this method, the output codes of LR1, LR2, and LR3 from time 1 to time 48 when the outer steel ring 801 rotates counterclockwise are (011), (001), (001), (001), (011)...(111).

[0068] Figure 3 This is a schematic diagram of an elevator speed control device based on a photoelectric speed sensor according to an embodiment of the present invention. Figure 3 As shown, the control device includes:

[0069] 2. Wire rope, 1. First lifting container, 3. First sheave, 4. Roller, 8. Speed ​​sensor, 5. Second sheave, 6. Second lifting container, 9. Speed ​​monitoring and control system, and 7. Elevator control room;

[0070] One end of the wire rope 2 is connected to the first lifting container 1 and passes around the first top sheave 3, roller 4, speed sensor 8 and second top sheave in sequence; the other end of the wire rope 2 is connected to the second lifting container 6.

[0071] The speed sensor 8 is connected to the speed monitoring and control system 9 via the connecting line 10. The speed sensor 8 and the speed monitoring and control system 9 can be fixedly installed in the elevator control room 7.

[0072] When the motor runs, the roller 4 also rotates. At the same time, the friction pad installed on the outer edge of the roller 4 generates friction with the wire rope 2. This friction force is used to make the wire rope 2 rotate, so as to realize the lifting and lowering transportation tasks of the first lifting container 1 and the second lifting container 6.

[0073] Speed ​​sensor 8 contacts wire rope 2 and presses against the wire rope 2 by adjusting the tension wheel of speed sensor 8. During the lifting and lowering transportation task, the friction between wire rope 2 and speed sensor 8 drives speed sensor 8. One end of wire rope 2 is connected to the first lifting container 1 and is wound on roller 4. Therefore, the linear speed of the wire rope can be detected to obtain the running speed of the elevator car.

[0074] Based on the above-described device of the present invention, the present invention further provides an elevator car speed control method based on low-frequency control, comprising the following steps:

[0075] Step 1: Acquire the pulse signal from the speed sensor.

[0076] Step 2: Input the pulse signal to the signal holding and shaping circuit for processing.

[0077] Step 3: Input the signal after being processed by the signal holding and shaping circuit to the microcontroller for processing to obtain the logic pulse width corresponding time and the number of standard high-frequency clock pulses.

[0078] Step 4: Calculate the speed of the wire rope based on the corresponding time of the logic pulse width and the number of standard high-frequency clock pulses.

[0079] Step 5: Calculate the elevator car speed based on the speed of the steel wire rope.

[0080] Step 6: Compare the elevator car's operating speed with the preset speed.

[0081] Step 7: Based on the comparison results, send control commands to the motor inverter to adjust the elevator car speed.

[0082] The speed sensor 8 outputs a coded value, which is processed by the speed monitoring and control device 9. The processing circuit block diagram of the speed monitoring and control device 9 is shown below. Figure 6 As shown, the speed monitoring and control device processing circuit 9 includes: a signal holding and shaping circuit, a microcontroller system, an RS485 interface, a display unit, and a power supply. The output level of the speed sensor 8 is transformed by the signal holding and shaping circuit into a processing level suitable for the microcontroller system. The microcontroller system then acquires the coded output value of the speed sensor 8. The microcontroller system acquires the levels of speed sensors LR1, LR2, and LR3 respectively, analyzes and processes them to obtain the logic pulse width corresponding to the time Ts (s is the unit of time, seconds), and simultaneously generates a standard high-frequency clock internally, with a clock frequency F MHz (MHz is the unit of frequency, megahertz). k Taking the start of time as an example, at time T k The timing program controls the microcontroller's internal counter to start counting the standard high-frequency clock pulses, until T... k+1 The timing program controls the microcontroller's internal counter to stop counting. The microcontroller's internal counter remembers the standard high-frequency clock pulse count as M. k ,but Furthermore, since the minimum logic pulse width per unit arc length of the 8 speed sensors is Therefore, the rotational speed of the outer steel ring 801 of the speed sensor 8 is If four 8-speed sensors are installed simultaneously, the average rotational speed of the outer steel ring 801 will be P. k =(V 1k +V 2k +V 3k +V 4k ) / 4 (where V 1k V 2k V 3k V 4k Press V respectively k (Calculation), and since the traction wire rope and the outer steel ring 801 rotate at the same speed, the linear velocity of the traction wire rope is also V. k (When there are 4 8-speed sensors, the average rotational speed P) k Considering the traction ratio of the elevator car and the traction steel cable, the speed of the elevator car is: E k =V k / i1 (i1 is the elevator car traction ratio), by real-time monitoring of the elevator car speed, and according to the ideal speed curve of the actual elevator operation, a speed control command is sent to the motor frequency converter via the RS485 interface to adjust the elevator running speed. The principle of determining the rotation position of the outer steel ring 801 of the speed sensor 8 is as follows: after the speed monitoring and control device 9 is first turned on or after a power outage and restart, ... Figure 3 Taking the clockwise rotation of the outer steel ring 801 as an example, at a certain moment LR1, LR2, LR3, the output code value is (111). Observing the subsequent three moments LR1, LR2, LR3, the output code values ​​are (111), (101), and (101) respectively. The microcontroller system can locate the current rotation position of the outer steel ring 801 as position 1 in the timing diagram by comparing and looking up the code value table of the outer steel ring 801 rotating clockwise for one revolution. If the subsequent three moments LR1, LR2, LR3 are observed, the output code values ​​are (111), (110), and (110) respectively. The microcontroller system can locate the current rotation position of the outer steel ring 801 as position 9 in the timing diagram by comparing and looking up the code value table of the outer steel ring 801 rotating clockwise for one revolution. In summary, the microcontroller system can locate the current position by observing the code values ​​of the speed sensor 8 at four consecutive moments.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0084] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A photoelectric speed sensor, characterized in that, The speed sensor includes: an outer steel ring, a ball bearing, an inner steel ring, a photoelectric switch assembly, and mounting holes; The balls are disposed between the outer steel ring and the inner steel ring to form a ball bearing structure; The photoelectric switch group is disposed on the inner side of the inner steel ring; the photoelectric switch group includes: a first photoelectric switch, a second photoelectric switch and a third photoelectric switch, the first photoelectric switch, the second photoelectric switch and the third photoelectric switch are evenly disposed on the inner side of the inner steel ring; the first photoelectric switch, the second photoelectric switch and the third photoelectric switch are all reflective infrared proximity tube photoelectric switches; the three reflective infrared proximity photoelectric switches are named LR1, LR2 and LR3 in sequence, and the included angle between each pair of LR1, LR2 and LR3 is θ3, θ3 = 120°; The mounting hole is formed on the inner steel ring for mounting and fixing the speed sensor; the mounting hole is coaxial with the inner steel ring; after assembly, the inner steel ring is fixed and does not rotate. The outer surface of the outer steel ring is provided with a groove; the steel wire rope is wound inside the groove. The inner rim of the outer steel ring is machined with concave and convex teeth of varying lengths; the arc angles of concave teeth CC1 and convex teeth CG1 are both θ2, and the arc angle of concave tooth CC2 is 2θ2. Designed to be 4θ2 = 90°, therefore θ2 = 22.5°. Thus, the arc length of concave tooth CC1 is... The arc length of the convex tooth CG1 is The arc length of the concave tooth CC2 is Similarly, the arc length of the concave tooth CC3 is The arc length of the convex tooth CG3 is The arc length of the concave tooth CC4 is The radian angle of the convex tooth CG4 is θ1, where θ1 = 90°. Therefore, the arc length of the convex tooth CG4 is... Similarly, the arc length of the convex tooth CG2 is L is the circumference of the outer steel ring, L = πD, and D is the diameter of the outer steel ring; when the outer steel ring rotates, the infrared light emitted by the photoelectric switch assembly illuminates the concave or convex teeth, forming light pulses of varying intensity. These light pulses are then processed and shaped into a standard 5V. TTL logic level; The distance between the reflective infrared proximity photoelectric switch and the concave tooth is large, so the reflective infrared proximity photoelectric switch receives weak light. After processing and shaping, it is converted to a logic low level, represented by 0. The logic signal received by the reflective infrared proximity photoelectric switch is 0. The distance between the reflective infrared proximity photoelectric switch and the convex tooth is small, so the reflective infrared proximity photoelectric switch receives strong light. After processing and shaping, it is converted to a logic high level, represented by 1. The logic signal received by the reflective infrared proximity photoelectric switch is 1. The principle of determining the rotation position of the outer steel ring of the speed sensor: After the speed monitoring and control device is powered on for the first time or restarted after a power failure, the outer steel ring rotates. At a certain moment, LR1, LR2, and LR3 output coded values ​​are the logic signals received by LR1, LR2, and LR3 in sequence. By continuously observing LR1, LR2, and LR3 at the next 3 moments, the output coded values ​​are arranged in sequence. By comparing and searching the system record of the coded values ​​of the outer steel ring for one revolution, the current rotation position of the outer steel ring can be located. By continuously observing the coded values ​​of the speed sensor at 4 moments, the current position of the elevator car can be located by software.

2. The photoelectric speed sensor according to claim 1, characterized in that, The groove is V-shaped.

3. The photoelectric speed sensor according to claim 1, characterized in that, The speed sensor further includes a seal, which is used to encapsulate the speed sensor.

4. An elevator running speed control device, characterized in that, The control device includes the photoelectric speed sensor as described in any one of claims 1-3, and the control device includes: Wire rope, first hoisting container, first hoisting wheel, rollers, photoelectric speed sensor, second hoisting wheel, second hoisting container, speed monitoring and control system; One end of the wire rope is connected to the first lifting container and passes sequentially around the first top sheave, roller, speed sensor and second top sheave; the other end of the wire rope is connected to the second lifting container. The photoelectric speed sensor is connected to the speed monitoring and control system.

5. The elevator running speed control device according to claim 4, characterized in that, The control device further includes an elevator control room, in which the speed sensor and the speed monitoring and control system are located.

6. The elevator running speed control device according to claim 4, characterized in that, The speed measurement and monitoring control system includes: Signal holding and shaping circuit, microcontroller, and display; The input terminal of the signal holding and shaping circuit is connected to the speed sensor, and the signal holding and shaping circuit is used to convert the output level of the speed sensor into a processing level suitable for the microcontroller system. The input terminal of the microcontroller is connected to the output terminal of the signal holding and shaping circuit, and the output terminal of the microcontroller is connected to the display. The microcontroller is used to acquire the output encoded value of the signal holding and shaping circuit. The microcontroller is also used to process the encoded value to obtain the logic pulse width corresponding time and the number of standard high-frequency clock pulses.

7. A method for controlling elevator running speed, characterized in that, The control method is applied to the control device as described in any one of claims 4-6, and the control method includes: Acquire the pulse signal from the photoelectric speed sensor; The pulse signal is input to a signal holding and shaping circuit for processing. The signal processed by the signal holding and shaping circuit is input to the microcontroller for processing to obtain the logic pulse width corresponding time and the number of standard high-frequency clock pulses. The speed of the wire rope is calculated based on the corresponding time of the logic pulse width and the number of standard high-frequency clock pulses. The elevator car speed is calculated based on the speed of the steel wire rope. The elevator car's operating speed is compared with a preset speed; Based on the comparison results, control commands are sent to the motor inverter to adjust the elevator car's running speed.

8. The elevator running speed control method according to claim 7, characterized in that, The control method, after "sending control commands to the motor inverter based on the comparison results to adjust the elevator car speed," also includes: The current position of the elevator car is determined based on the elevator car's operating speed.

9. The elevator running speed control method according to claim 7, characterized in that, The speed of the wire rope is calculated based on the corresponding time of the logic pulse width and the number of standard high-frequency clock pulses using the following formula: Where L is the circumference of the outer steel ring, F is the standard high-frequency clock frequency, and M... k This represents the standard high-frequency clock pulse count.

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