CN110697530A - A method for detecting the absolute position of an elevator car - Google Patents

Abstract

The invention relates to a method for detecting the absolute position of an elevator car. The method is based on a millimeter wave sensor based on the continuous wave frequency modulation (FMCW) theory to detect the absolute position of the elevator. Therefore, the problems in the current elevator position detection scheme, such as detection deviation caused by slippage of rotating parts, and loss of elevator position information caused by system power failure, are solved. In addition, the detection method of the present invention will not cause the location information to be unable to be detected or the detection to be inaccurate due to environmental factors such as light and smoke. The method includes the following steps: installing the millimeter wave detection device at the proper position of the hoistway, and adjusting the angle; configuring the parameters of the millimeter wave measuring chip, starting to measure the current position information of the elevator car in real time after power-on, and sending it to the elevator host controller through the communication interface , used for elevator main controller control and drive.

Description

A method for detecting the absolute position of an elevator car

technical field

The invention relates to the technical field of elevators, in particular to a method for detecting the absolute position of an elevator car.

Background technique

As an indispensable vertical vehicle in modern society, the elevator control system needs to accurately detect the current position of the car in order to realize the relevant logic and safety control functions.

At present, the commonly used elevator car position detection methods are as follows:

1. Rotary encoder measurement method.

This method obtains the position data of the car through the rotation of the traction sheave or the anti-sheave. In this method, due to the large inertia of the traction sheave or the anti-sheave, the wire rope on the sheave is prone to large elastic slip, and the error is relatively small. And when the elevator encounters a fault during the express running process and needs to stop in an emergency, due to the large inertia of the car, the traction wire rope will have obvious mechanical slippage with the traction sheave. At this time, the traction sheave stops due to the brake action and rotates. The encoder cannot detect the slipping distance of the wire rope.

2. Photoelectric sensor or position switch detection method.

The method detects the area where the elevator car is located through the photoelectric sensor or the position switch installed on the hoistway or the car. The detection accuracy of this method is low, and the detection can only be realized within the area.

3. The method of detecting the position of special markers of scales.

In the method, the sensor installed on the elevator car detects the information of the pre-set code band in the hoistway to determine the position of the elevator car. The coding tape needs to be coded by related technologies, which is expensive, and the coding tape is easily broken when installed in the hoistway, and the coding information is easily affected by electromagnetic, temperature, oil pollution, etc.

In view of the problems of the above detection methods, the patent "Elevator Car Jedi Position Detection System and Detection Method, Patent No.: CN 105151940" proposes an image recognition method based on CCD sensor to detect the absolute position of the car, but this method It is easy to be affected by light and occluders, which leads to measurement failure, and the measurement system and algorithm of this method are relatively complex.

SUMMARY OF THE INVENTION

Based on the current problems in the detection of the absolute position of the elevator car, the present invention provides a method for detecting the absolute position of the elevator car. Moreover, the algorithm of the measurement system is simple, the real-time performance is good, and the application is convenient.

For realizing the purpose of the present invention, the technical scheme adopted is:

A method for detecting the absolute position of an elevator car, comprising an electromagnetic wave detection device, an elevator car, and an elevator main controller, wherein the electromagnetic wave detection device is communicated and connected with the elevator main controller through a communication interface and a communication line; The current car position can be calculated by the time difference between the electromagnetic wave transmitted by the electromagnetic wave detection device to the car through the electromagnetic wave transmitting antenna and the electromagnetic wave reflected from the car received by the electromagnetic wave receiving antenna.

The car position measured by this method can accurately detect the current position of the car in real time. or inaccurate detection.

In a preferred embodiment of the present invention, the electromagnetic wave detection device is a millimeter wave detection device, the electromagnetic wave transmitting antenna is a millimeter wave transmitting antenna, and the electromagnetic wave receiving antenna is a millimeter wave receiving antenna.

In a preferred embodiment of the present invention, the millimeter-wave detection device is installed on the top of the hoistway, the electromagnetic waves emitted by the millimeter-wave transmitting antenna are focused on the top of the car, and the electromagnetic waves received by the millimeter-wave receiving antenna are focused on the top of the car. The electromagnetic wave reflected from the car is the electromagnetic wave reflected from the top of the car; it is used to measure the distance between the millimeter wave detection device and the top of the car to calculate the real-time position of the car.

In a preferred embodiment of the present invention, the millimeter-wave detection device is installed at the bottom of the hoistway, the electromagnetic waves emitted by the millimeter-wave transmitting antenna are focused on the bottom of the car, and the electromagnetic waves received by the millimeter-wave receiving antenna are focused on the bottom of the car. The electromagnetic wave reflected from the car is the electromagnetic wave reflected from the bottom of the car; it is used to measure the distance between the millimeter wave detection device and the bottom of the car to calculate the real-time position of the car.

The millimeter-wave detection device installed on the top of the hoistway is one of the detection solutions. At this time, the distance between the millimeter-wave detection device and the top of the car can be measured to calculate the real-time position of the car. The millimeter wave detection device can also be installed at the bottom of the hoistway. At this time, the measured value is the distance between the bottom of the hoistway and the bottom of the car, and the current position of the car can also be calculated. The installation location can be flexibly selected according to the site conditions, which is convenient for construction and reduces construction time.

In a preferred embodiment of the present invention, the millimeter-wave transmitting antenna and/or the millimeter-wave receiving antenna are both millimeter-wave microstrip array antennas. In this way, the millimeter-wave field of view (FOV) is within a suitable scanning range, eliminating the interference of irrelevant objects in the hoistway, allowing the millimeter-wave detection signal to focus only on the top or bottom of the car, and improving the detection accuracy.

In a preferred embodiment of the present invention, the data refresh rate of each frame of the millimeter wave detection device is millisecond level. In this way, the position information of the car is fed back to the main elevator controller in a more timely manner, and the real-time performance is better.

In a preferred embodiment of the present invention, the millimeter wave detection device communicates with the elevator main controller, the millimeter wave detection device transmits the real-time distance data of the car to the elevator main controller, and the elevator main controller receives the The distance value to get the current car position.

In a preferred embodiment of the present invention, the millimeter wave detection device communicates with the elevator main controller, and the millimeter wave detection device directly sends the detected distance to the elevator main controller, which is controlled by the elevator main controller. The computer calculates the current position of the car. In this way, the elevator main controller does not need to perform excessive data processing work, thereby reducing the burden on the elevator main controller and improving the real-time performance.

In a preferred embodiment of the present invention, the time difference between the electromagnetic wave transmitted by the electromagnetic wave detection device to the car through the electromagnetic wave transmitting antenna and the electromagnetic wave reflected from the car received by the electromagnetic wave receiving antenna is measured by millimeter waves. The millimeter wave chip inside the detection device calculates the distance between the detection device and the target, and then the current car position can be calculated.

In a preferred embodiment of the present invention, the distance between the millimeter wave detection device and the non-elevator car can be eliminated through parameter configuration of the millimeter wave chip, post-processing of data, etc., and only the distance between the elevator car and the elevator car can be retained. distance information.

Compared with the prior art, the present invention has the following advantages:

The millimeter wave detection device of the invention can accurately detect the actual position of the car in real time, and is not affected by factors such as the slip of rotating parts, sudden power failure, etc., and will not be detected or detected due to environmental factors such as light and smoke. precise. In addition, the detection device of the present invention is a non-contact detection, the detection device is small in size, easy to install, does not increase construction time and cost, and has a wide application range.

Description of drawings

FIG. 1 is a schematic structural diagram of a car absolute position detection system according to an embodiment of the present invention.

Fig. 2 is a working schematic diagram of an elevator car absolute position detection system according to an embodiment of the present invention.

Fig. 3 is a schematic block diagram of a millimeter wave detection device in an elevator car absolute position detection system.

Description of reference numerals: hoistway 10, hoistway top 110, hoistway bottom 120, hoistway inner wall 130, elevator car 20 located in the hoistway, car top 210, car bottom 220, millimeter wave detection device 30 for distance measurement, A communication cable 310 , a millimeter wave receiving antenna 320 , a millimeter wave transmitting antenna 330 , and an elevator main controller 40 are used for the communication between the millimeter wave detection device 30 and the elevator main controller 40 .

Detailed ways

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, and the present invention includes, but is not limited to, the situations described in the embodiments.

As shown in FIG. 1, an elevator car absolute position detection system includes a hoistway 10, a hoistway top 110, a hoistway bottom 120, an inner wall 130 of the hoistway, an elevator car 20 located in the hoistway, a car top 210, a car bottom 220, A millimeter wave detection device 30 for distance measurement, a communication cable 310 for communication between the millimeter wave detection device 30 and the elevator main controller, and the elevator main controller 40 .

The millimeter wave detection device 30 is installed on the top of the hoistway 110, and the current absolute position of the elevator car 20 is calculated by measuring the distance between the millimeter wave detection device 30 and the top of the car 210, and the detected distance value is sent to the elevator through the communication cable 310. The main controller 40 is used when the elevator main controller 40 is in control. Of course, the millimeter-wave detection device 30 can also be installed at the bottom of the hoistway 120, and the current absolute position of the elevator car 20 is calculated by measuring the distance between the millimeter-wave detection device 30 and the car bottom 220, and the detected distance value is passed through the communication cable. 310 is sent to the elevator main controller 40 for use by the elevator main controller 40 during control.

Referring to FIG. 2 , the millimeter wave detection device 30 transmits electromagnetic waves 50 through a millimeter wave transmitting antenna 330 , and the electromagnetic waves 50 form reflected electromagnetic waves 60 after encountering an object, and receive the reflected millimeter waves through a millimeter wave receiving antenna 320 . The millimeter-wave detection device 30 processes the transmitted millimeter-wave and the received millimeter-wave signal, so as to calculate the distance R of the target 210. The basic calculation formula is:

Among them, C is the speed of light, and T is the total time that the electromagnetic wave emitted by the millimeter wave detection device propagates in the air.

Regardless of whether the elevator is in a static state or in a running state, the millimeter wave detection device 30 can measure the current distance of the elevator car 20 , and then can obtain the current floor information of the elevator car 20 through the elevator main controller 40 .

FIG. 3 illustrates a process of distance detection by the millimeter wave detection device 30 in this embodiment. After proper parameter configuration of the millimeter-wave chip 340 in the millimeter-wave detection device 30, the millimeter-wave chip emits a Chirp signal, and the Chirp signal reflects the signal back when it encounters an object. The inside of the millimeter-wave chip 340 will be based on the millimeter-wave communication theory Calculate and process the Chirp signal and the echo signal, eliminate the non-target signal, identify the target signal, and obtain the final distance value through DFFT. Then, the final distance value is transmitted to the elevator main controller 40 via the communication interface.

The millimeter wave chip 340 includes a radio frequency front-end module, a radio frequency front-end control module, a data acquisition and processing module, a data processing control module, a data buffer module, and a communication interface.

Claims (10)

1. The elevator car absolute position detection method is characterized by comprising an electromagnetic wave detection device, an elevator car and an elevator main controller, wherein the electromagnetic wave detection device is in communication connection with the elevator main controller through a communication interface and a communication line; when the elevator is in a static or running state, the electromagnetic wave detection device can calculate the current position of the elevator car through the time difference between the electromagnetic wave transmitted to the elevator car by the electromagnetic wave transmitting antenna and the electromagnetic wave reflected from the elevator car and received by the electromagnetic wave receiving antenna.

2. The elevator car absolute position detecting method according to claim 1, wherein the electromagnetic wave detecting means is a millimeter wave detecting means, the electromagnetic wave transmitting antenna is a millimeter wave transmitting antenna, and the electromagnetic wave receiving antenna is a millimeter wave receiving antenna.

3. The method for detecting the absolute position of the elevator car as claimed in claim 2, wherein the millimeter wave detection device is installed at the top of the hoistway, the electromagnetic wave transmitted by the millimeter wave transmitting antenna is focused on the top of the car, and the electromagnetic wave reflected from the car and received by the millimeter wave receiving antenna is reflected from the top of the car; the distance between the millimeter wave detection device and the top of the car is measured to calculate the real-time position of the car.

4. The method for detecting the absolute position of the elevator car according to claim 2, wherein the millimeter wave detection device is installed at the bottom of the hoistway, the electromagnetic wave transmitted by the millimeter wave transmitting antenna is focused on the bottom of the car, and the electromagnetic wave reflected from the car and received by the millimeter wave receiving antenna is reflected from the bottom of the car; the device is used for measuring the distance between the millimeter wave detection device and the bottom of the car to calculate the real-time position of the car.

5. The elevator car absolute position detection method of claim 2, wherein the millimeter wave transmitting antenna and/or the millimeter wave receiving antenna are millimeter wave microstrip array antennas.

6. The method of claim 2, wherein the millimeter wave detection device refreshes data per frame at a rate of milliseconds.

7. The method as claimed in claim 2, wherein the millimeter wave detection device communicates with the elevator master controller, the millimeter wave detection device transmits real-time distance data of the car to the elevator master controller, and the elevator master controller obtains the current position of the car from the received distance value.

8. The method as claimed in claim 2, wherein the millimeter wave detection device communicates with the elevator main controller, the millimeter wave detection device directly transmits the detected distance to the elevator main controller, and the elevator main controller calculates the current position of the car.

9. The method as claimed in claim 2, wherein the electromagnetic wave detecting device calculates the current car position by calculating the distance between the detecting device and the target object by the millimeter wave chip in the millimeter wave detecting device according to the time difference between the electromagnetic wave transmitted from the electromagnetic wave transmitting antenna to the car and the electromagnetic wave reflected from the car and received by the electromagnetic wave receiving antenna.

10. The method for detecting the absolute position of the elevator car as claimed in claim 9, wherein the distance between the millimeter wave detection device and the non-elevator car can be eliminated by parameter configuration of the millimeter wave chip, data post-processing and the like, and only the distance information of the elevator car is reserved.

Images