CN102344063A - Detection system of elevator sedan absolute position - Google Patents

Abstract

The invention provides a detection system for the absolute position of an elevator car, which includes a car, a speed limiter, a position detection circuit board, an elevator main control board and an incremental encoder. on the roller shaft that is in contact with the wheel edge of the speed limiter. The detection system for the absolute position of the elevator car of the present invention can accurately calculate the moving distance of the elevator car, thereby calculating the absolute position of the elevator car, and detecting the speed of the speed limiter, so as to realize the overspeed protection of the elevator and ensure the safety of the elevator operation. And the cost is low.

Description

Detection System of Absolute Position of Elevator Car

technical field

The invention relates to the field of elevators, in particular to a detection system for the absolute position of an elevator car.

Background technique

At present, in the elevator industry, there are two main methods for detecting the absolute position of the elevator car after the elevator stops suddenly or the elevator is powered off:

1. The measurement method of the incremental encoder of the traction sheave of the main motor. This method is to install an incremental encoder on the rotating shaft of the traction sheave of the main motor, and detect the rotating speed of the motor and the position of the car at the same time. This method has the following disadvantages:

a. The acceleration and deceleration of the elevator operation all occur on the traction sheave of the main motor. The change of speed, the weight deviation of the counterweight side and the two sides of the car is large, so that the slipping of the traction sheave of the main motor and the wire rope cannot be ignored, and frequent corrections are required.

b. When the elevator encounters a fault and stops suddenly during express running, the brake of the main motor is released and the traction sheave stops suddenly. Due to the large mass and inertia of the car, the steel wire rope and the traction sheave slip. At this time, the traction sheave of the main engine has Locked by the brake, the incremental encoder cannot detect the slipping distance of the car, and cannot determine the exact position of the car.

c. The sliding distance of the elevator emergency stop cannot be detected, that is, the position of the car cannot be confirmed after the failure, and it needs to run to the corrected position of the base station by self-rescue before the elevator can return to normal and release the trapped passengers. However, the floors of current buildings are getting higher and higher. If the elevator fails and stops suddenly at the upper floors, it will take a long time to return to the base station for correction at the maintenance speed (15m/min).

d. After the elevator is powered off, the incremental encoder on the traction sheave of the main motor is powered off. At this time, if the cranking moves the position of the car, the exact position of the car cannot be measured.

2. The speed limiter is installed with an absolute encoder system. This method is to use the hard connection between the speed limiter wire rope and the car. The moving distance of the car is equal to the rotation distance of the speed limiter. An absolute encoder is installed on the speed limiter. device, the turning distance of the direct speed limiter. Its advantage is that it can detect the slip distance of the car when it is in an emergency stop, and it can also detect the position of the car after a power failure. However, it also has disadvantages:

a. The tension of the wire rope of the speed governor is only maintained by the weight of about 40KG ~ 80KG hanging from the pit, and the length of the wire rope will gradually elongate, which limits the measurement accuracy.

b. The high cost of the absolute encoder limits the application of the car position confirmation system.

Contents of the invention

The purpose of the present invention is to provide a detection system for the absolute position of the elevator car, which can overcome the defects of the prior art, and can accurately confirm the position of the elevator car when the elevator stops suddenly or loses power.

The present invention is achieved like this:

A detection system for the absolute position of an elevator car, which includes a car, a speed limiter, a position detection circuit board, an elevator main control board and an incremental encoder, the incremental encoder is installed on the speed limiter on the roller shaft that is in contact with the edge of the wheel.

Preferably, it also includes a roller, and the roller is in contact with the wheel edge of the speed governor, so that the rotation distance of the speed governor is equal to the rotation distance of the roller.

Preferably, it also includes a differential signal conversion module, the three phases A, B, and Z of the incremental encoder are respectively connected to the differential signal conversion module, and the differential signal conversion module is arranged at the position detection circuit board;

Wherein, the differential signal conversion module converts the double-pulse signal output by the incremental encoder into a single-pulse signal, so as to obtain the number N of pulse signals output by the incremental encoder.

Preferably, the differential signal conversion module is a differential signal receiving chip.

Preferably, the position detection circuit board is provided with a calculation unit, the differential signal conversion module is connected to the calculation unit, and the calculation unit calculates the rotation distance of the speed limiter according to S=(NC)/R ;

Wherein, C=πD, D is the diameter of the speed limiter, and R is the resolution of the incremental encoder.

Preferably, it also includes a battery device connected to the position detection circuit board.

Compared with the prior art, the present invention has the following beneficial effects:

The detection system for the absolute position of the elevator car of the present invention can accurately calculate the moving distance of the elevator car, thereby calculating the absolute position of the elevator car, and detecting the speed of the speed limiter, so as to realize the overspeed protection of the elevator and ensure the safety of the elevator operation. And the cost is low.

Description of drawings

Fig. 1 is the structural representation of the detection system of the absolute position of elevator car of the present invention;

Fig. 2 is a schematic diagram of the detection system for the absolute position of the elevator car of the present invention during operation.

Detailed ways

Embodiments of the present invention are described in detail below in conjunction with accompanying drawings:

As shown in Figure 1, the detection system of the absolute position of the elevator car of the present invention includes a guide wheel 1, a main engine traction sheave 2, a car side anti-rope pulley 8, a car 9 and a counterweight 10, a speed limiter 3, a roller 4. Incremental encoder 12, position detection circuit board 5, elevator main control board 6 and limiter tensioning device 11. Wherein, the rope passes through the counterweight 10, the guide wheel 1, the main machine traction sheave 2 and the car-side anti-rope pulley 8 in sequence, and the rope passes through the car-side anti-rope pulley 8 to lift the car 9 , and the counterweight 10 and the car 9 are movably fixed on both sides of the guide wheel 1 and the main engine traction wheel 2 respectively. Wherein, the connection relationship among the stopper 3 , the stopper tensioning device 11 and the car 9 already belongs to the prior art, and the present invention will not repeat them here.

In the present invention, an incremental encoder (not shown) is installed on the rotating shaft of the traction sheave 2 of the main engine, and an incremental encoder is also installed on the rotating shaft of the roller 4 in contact with the speed governor 3 12.

The roller 4 of the absolute position detection system of the elevator car is in contact with the wheel edge of the speed governor 3, so the rotation distance of the speed governor 3 is equal to the rotation distance of the roller.

The incremental encoder 12 outputs differential signals A+, A-, B+, B-, Z+, Z- in order to enhance the anti-interference ability of the pulse signal it outputs, and the position detection circuit board 5 needs to obtain the The number of pulses output by the incremental encoder 12 is used to obtain the rotation angle of the incremental encoder 12 . The detection system for the absolute position of the elevator car also includes a differential signal conversion module, and the three phases A, B, and Z of the incremental encoder 4 are respectively connected to the differential signal conversion module on the position detection circuit board 5 . Taking the A phase of the incremental encoder 12 as an example, the A phase outputs A+, A-, with A- as the reference voltage output, and the position detection circuit board 5 generally uses ground 0V as the reference voltage, and the position detection In order to detect the output pulse quantity of the A phase of the incremental encoder 12, the circuit board 5 must use a differential signal receiving chip to convert A+, A- into a single pulse signal with ground as the reference voltage. Therefore, the single pulse signal The number is the number N of pulse signals output by the incremental encoder 4 .

In this preferred embodiment, the differential signal conversion module is a differential signal receiving chip.

The position detection circuit board 5 is provided with a calculation unit, the differential signal conversion module is connected to the calculation unit, and the calculation unit calculates the rotation distance of the speed limiter according to S=(NC)/R; wherein, C=πD, D is the diameter of the speed limiter 3, R is the resolution of the incremental encoder, the user can choose different resolutions according to their own needs, the higher the resolution, the final elevator car obtained The higher the accuracy of movement. The car 9 is hard-connected to the speed governor 3 , and the displacement of the car 9 is equal to the rotation distance of the speed governor 3 . Assume that the incremental encoder 12 is mounted on the shaft of the roller 4 with a diameter of D=80mm in contact with the wheel edge of the speed governor 3 , and the rotation distance of the speed governor 3 is equal to the rotation distance of the roller 4 .

Finally, according to the existing method for judging whether the elevator car is rising or falling, it is obtained whether the elevator car is rising or falling, and the method for judging whether the elevator car is rising or falling belongs to the prior art, and the present invention will not repeat them here; In addition, the position detection circuit board 5 transmits the detected position data to the elevator main control board 6, and calculates the rotation distance of the speed governor 3 (that is, the moving distance of the car) according to this data to obtain the specific position of the elevator car 9. Location.

In order to avoid that the incremental encoder 12 and the position detection circuit board 5 are also powered off when the elevator is powered off, the detection system of the absolute position of the elevator car also includes a battery device 7, and the battery device 7 It is connected with the position detecting circuit board 5 . In this preferred embodiment, the battery device 7 is preferably a lithium battery.

In order to ensure the accuracy of the position data detected by the incremental encoder 12, three corrections are used:

The first type: use the Z relative pulse check of the incremental encoder 12 . When the incremental encoder 12 rotates a circle, the Z phase of the incremental encoder 12 will output a pulse, and the resolution R of the incremental encoder 4 and the incremental encoder 12 will output a circle. Compared with the number of pulses, it can be judged whether the encoder pulse is lost and corrected.

The second type: when the elevator car 9 is at the end station, the elevator main control board 6 corrects the position data of the position detection circuit board 5 to eliminate the error accumulation of the slipping of the roller 4 and the speed governor 3; wherein, the The above position data includes: 11-bit single-turn rotation angle pulse data of the incremental encoder; 13-bit incremental encoder rotation number data. Take the incremental encoder 12 with a resolution R of 512 as an example, 512*4 (the 4 here is the 4 times the frequency of the detection of the rising edge and falling edge of the AB phase), in the case of no error, the resolution The rate is: 512*4=2 ¹¹ =2048. When the elevator car is going up, the position data counter is incremented, and when the elevator car is going down, the position data counter is decremented. At the end station, the position data of the position detection circuit board 5 is regarded as 0 and counted.

The third type: when the elevator car is running, the elevator main control board 6 compares the floor height data of the elevator car with the position data of the position detection circuit board 5, if the deviation between the two exceeds the allowable value, the The elevator car 9 returns to the end station for position correction. As shown in Figure 2, here, the floor height table data refers to the incremental encoder pulse data on the main machine traction sheave 2, which is converted into car position data and recorded when the elevator is running at the floor height. Floor height data. When running at the floor height, record the position data of the incremental encoder on the traction sheave 2 of the main engine and the incremental encoder 12 on the speed limiter 3 when leaving the magnetic isolation plate at the bottom layer as X ₁ , X _2. The position data Y ₁ and Y ₂ when entering the top-layer magnetic isolation plate are calculated to obtain the rotation distance (mm) of the incremental encoder of the traction sheave 2 of the main engine and the incremental encoder 12 of the speed limiter 3. Pulse data ratio A=(Y ₂ -X ₂ )/(Y ₁ -X ₁ ), assuming that the position data detected by the incremental encoder on the speed limiter is S ₁ , then the real-time position of the car is S ₂ =S ₁ x A.

The above are only specific embodiments of the present invention, and do not limit the protection scope of the present invention; any replacement and improvement made on the basis of not violating the concept of the present invention shall fall within the protection scope of the present invention.

Claims (6)

1. A detection system for the absolute position of an elevator car, which includes a car, a speed limiter, a position detection circuit board and an elevator main control board, is characterized in that it also includes an incremental encoder, and the incremental The type encoder is installed on the roller shaft in contact with the wheel edge of the speed governor. 2. The detection system of the absolute position of the elevator car as claimed in claim 1, characterized in that it also includes a roller, and the roller is in contact with the wheel edge of the speed governor to make the rotation of the speed governor The distance is equal to the turning distance of the roller. 3. The detection system of the absolute position of the elevator car as claimed in claim 2, is characterized in that it also includes a differential signal conversion module, and the A, B, and Z phases of the incremental encoder are respectively connected to the The differential signal conversion module is connected, and the differential signal conversion module is arranged on the position detection circuit board; Wherein, the differential signal conversion module converts the double-pulse signal output by the incremental encoder into a single-pulse signal, so as to obtain the number N of pulse signals output by the incremental encoder. 4. The detection system for the absolute position of the elevator car according to claim 3, wherein the differential signal conversion module is a differential signal receiving chip. 5. The detection system of the absolute position of the elevator car as claimed in claim 2, wherein the position detection circuit board is provided with a calculation unit, the differential signal conversion module is connected with the calculation unit, and the calculation unit Calculate the rotation distance of the speed limiter according to S=(NC)/R; Wherein, C=πD, D is the diameter of the speed limiter, and R is the resolution of the incremental encoder. 6. The detection system for the absolute position of the elevator car according to claim 1, further comprising a battery device connected to the position detection circuit board.

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