A method for actively suppressing elevator car vibration

Abstract

The present invention belongs to the technical field of elevator equipment, and provides a method for actively suppressing vibration of an elevator car, which mainly includes the following steps: S10. Setting an absolute position detection device of the elevator car to obtain real-time position data S of the elevator car; S20. Adding a vibration control module to the operation control system of the elevator, the signal input end of the vibration control module is connected to the absolute position detection device, and the signal output end of the vibration control module outputs the elastic torque compensation value T of the wire rope to the current control module in the operation control system; S30. According to the elastic torque compensation value T of the wire rope obtained, the PWM instruction output by the current control module to the host is adjusted to control the rotation speed of the host. The present invention can offset the elastic vibration of the wire rope, thereby realizing the active suppression of mechanical resonance in the operation of the elevator car and improving the user experience.

Description

Technical Field

[0001] The present invention belongs to the technical field of elevator equipment, and particularly relates to a method for actively suppressing elevator car vibration. Background Art

[0002] During the operation of a conventional elevator car, if passengers walk, jump inside the car or due to poor installation of guide rails, it will cause vertical impacts during the operation of the car. Since the car is suspended in the building hoistway by steel ropes, and the steel ropes themselves have certain elastic deformation characteristics, the car, as a heavy object, will generate mechanical resonance at a certain frequency due to the above impacts and continue for a relatively long period. The generation of this vibration will affect the experience of passengers taking the elevator.

[0003] In a traditional elevator speed control system, it relies on a rotary encoder installed on the motor side to achieve closed-loop speed control of the motor. During the above elevator operation, mechanical impacts caused by certain reasons will lead to resonance of the elevator suspension system. This mechanical resonance is mainly caused by the elastic characteristics of the steel ropes. In the operation control of the motor, this vibration can basically not be detected by the rotary encoder on the motor side. Therefore, according to the speed control architecture of traditional elevators, this type of mechanical resonance cannot be handled. Summary of the Invention

[0004] In order to overcome the above-mentioned drawbacks of the prior art, the purpose of the present invention is to provide a method for actively suppressing elevator car vibration to offset the elastic vibration of the steel ropes, thereby achieving active suppression of mechanical resonance and improving the user experience.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0006] A method for actively suppressing elevator car vibration includes the following steps:

[0007] S10. Set an absolute position detection device for the elevator car to obtain real-time position data S of the elevator car;

[0008] S20. Add a vibration control module to the elevator operation control system. The signal input end of the vibration control module is connected to the absolute position detection device, and the signal output end of the vibration control module outputs an elastic torque compensation value T of the steel ropes to the current control module in the operation control system; where,

[0009] T = m * a(t) * r * ha / L / hk (1)

[0010] In Equation (1), m is the mass of the elevator car, a(t) is the instantaneous acceleration of the elevator car, r is the radius of the rope pulley on the main machine, ha is the torque correction coefficient, L is the distance between the elevator car and the main machine, and hk is the elastic torque compensation coefficient per unit length of the steel wire rope;

[0011] S30. According to the obtained elastic torque compensation value T of the steel wire rope, adjust the PWM command output by the current control module to the main machine to control the rotation speed of the main machine.

[0012] Preferably, the absolute position detection device is a grating scale detection device provided corresponding to the elevator car.

[0013] Preferably, after obtaining the real-time position data S of the elevator car, according to:

[0014] V(t) = dS / dt (3)

[0015] a(t) = dv / dt (4)

[0016] The instantaneous speed of the elevator car is obtained by Equation (3), and according to the obtained instantaneous speed and Equation (4), the instantaneous acceleration a(t) of the elevator car is obtained.

[0017] Preferably, the operation control system further includes a current feedback module. The signal input end of the current feedback module is connected with a current detection device, and the current detection device is used to detect the current of the motor on the main machine;

[0018] The signal output end of the current feedback module is connected to the current control module.

[0019] Preferably, the operation control system further includes a speed control module. The signal output end of the speed control module is connected to the current control module;

[0020] The signal input end of the speed control module receives a rated speed command and the actual speed value feedback by the encoder of the main machine respectively.

[0021] Preferably, the operation control system further includes a main machine speed feedback module. The signal input end of the main machine speed feedback module is connected to the encoder of the main machine;

[0022] The signal output end of the main machine speed feedback module is connected to the speed control module.

[0023] Compared with the prior art, the beneficial effects of the present invention include:

[0024] In this solution, an absolute position detection device is provided for the elevator car, and a vibration control module is added to the elevator operation control system, so that the elastic torque compensation value T of the wire rope can be obtained by measuring the actual position data of the elevator car, and then the PWM command obtained by the main machine can be adjusted according to the elastic torque compensation value T of the wire rope to control the rotation speed of the main machine, so that the elastic vibration of the wire rope can be offset in time, and the mechanical resonance occurring during the operation of the elevator car can be actively suppressed, so that the smoothness of the elevator car during operation is better and the user experience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic diagram of the traction structure of the elevator in the present invention.

[0027] Figure 2 It is a comparison schematic diagram of the elevator car operation speed curves in the present invention.

[0028] Figure 3 It is a system control block diagram in Embodiment 1 of the present invention.

[0029] Figure 4 It is a system control block diagram in Embodiment 2 of the present invention.

[0030] Wherein:

[0031] 1 - elevator car, 2 - grating ruler, 3 - grating ruler sensor, 4 - wire rope, 5 - main machine. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be described in detail below with reference to the drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Many specific details are set forth in the following description in order to fully understand the present invention. The described embodiments are only some embodiments of the present invention, not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention.

[0034] Embodiment 1

[0035] As Figures 1-3 shown, in this embodiment, an active vibration suppression method for an elevator car is provided, which mainly includes the following steps:

[0036] S10. Corresponding to the elevator car 1, an absolute position detection device capable of detecting the real-time position of the elevator car 1 is provided to obtain the real-time position data S of the elevator car 1. In this embodiment, the absolute position detection device is a grating scale detection device provided corresponding to the elevator car 1. The grating scale detection device includes a grating scale 2 arranged along the running track of the elevator car 1 and a grating scale sensor 3 arranged on the elevator car 1 and moving synchronously with the elevator car 1. The specific settings of the grating scale 2 and the grating scale sensor 3 can refer to the prior art and will not be elaborated here. Through the detection and feedback between the grating scale 2 and the grating scale sensor 3, the real-time position data S of the elevator car 1 can be obtained.

[0037] S20. A vibration control module is added to the operation control system of the elevator. In this embodiment, the operation control system of the elevator includes the above-mentioned vibration control module, current control module, current feedback module, speed control module, and host speed feedback module.

[0038] Specifically, the signal input end of the vibration control module is connected to the absolute position detection device, and the signal output end of the vibration control module outputs the elastic torque compensation value T of the wire rope 4 to the current control module in the operation control system; among them, the elastic torque compensation value T of the wire rope 4 is obtained by the following formula:

[0039] T = m * a(t) * r * ha / L / hk (1)

[0040] In formula (1):

[0041] m is the mass of the elevator car 1, and the corresponding data can be obtained by directly measuring the elevator car 1.

[0042] a(t) is the instantaneous acceleration of the elevator car 1; in this embodiment, after obtaining the real-time position data S of the elevator car 1, according to:

[0043] V(t) = dS / dt (3)

[0044] a(t) = dv / dt (4)

[0045] Through Equation (3), the instantaneous speed of the elevator car 1 can be obtained. Based on the obtained instantaneous speed and Equation (4), the instantaneous acceleration a(t) of the elevator car 1 can be obtained.

[0046] r is the radius of the rope pulley on the main machine 5, which can be directly obtained by measurement or the dimensional parameters of the rope pulley.

[0047] ha is the torque correction coefficient, and its value is usually taken as 0.7 - 1.0.

[0048] The accelerating torque of the vibration of the elevator car 1 is reflected on the main machine 5 side and is affected by the length of the steel wire rope 4 between the main machine 5 and the elevator car 1, and can be compensated by the factor L / hk in Equation (1).

[0049] L is the distance between the elevator car 1 and the main machine 5, which can be obtained by the feedback of the absolute position detection device.

[0050] hk is the elastic torque compensation coefficient per unit length of the steel wire rope, which can be preset according to the model of the steel wire rope 4.

[0051] S30. According to the obtained elastic torque compensation value T of the steel wire rope 4, adjust the PWM command output by the current control module to the main machine 5 according to Equation (5) to control the rotational speed of the motor on the main machine 5.

[0052]

[0053] Among them, T 0 is the control torque output by the speed control module, I m is the rated current of the motor, T m is the rated torque of the motor.

[0054] As an application example, when the elevator car 1 has an impact vibration during operation, by obtaining the elastic torque compensation value T of the steel wire rope 4, adjust the magnitude of the current output to the motor in the main machine 5, so as to control the rotational speed of the motor in the main machine 5; for example, when vibrating, the steel wire rope 4 is in a slack state, at this time, control the motor to output at an increased rotational speed so that the steel wire rope 4 returns to a relatively taut state; another example is that the steel wire rope 4 is in a stretched state, at this time, control the motor to output at a reduced rotational speed so that the steel wire rope 4 returns to a relatively compressed state. In this way, the elastic vibration of the steel wire rope 4 is offset, so as to actively suppress the mechanical resonance phenomenon and ensure the stable operation of the elevator car 1.

[0055] Further, in this embodiment, a current detection device is connected to the signal input end of the current feedback module, and the current detection device is used to detect the current of the motor on the host 5; the signal output end of the current feedback module is connected to the current control module, so as to realize the closed-loop detection and adjustment of the motor current.

[0056] In addition, the signal output end of the speed control module is connected to the current control module; the signal input end of the speed control module respectively receives a rated speed command and the actual speed value fed back by the encoder of the host 5. By comparing the actual speed value fed back by the encoder with the rated speed issued by the system, and then outputting the comparison conclusion signal to the current control module to adjust the rotation speed of the motor, so as to realize the closed-loop detection and adjustment of the motor rotation speed.

[0057] As a preferred solution, in this embodiment, the signal input end of the host speed feedback module is connected to the encoder of the host 5, and the signal output end of the host speed feedback module is connected to the speed control module, so as to calculate and sort out the data detected from the encoder through the host speed feedback module, and output the corresponding data type to the speed control module.

[0058] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Therefore, any modifications, equivalent changes and decorations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for actively suppressing elevator car vibration, characterized in that: The steps include: S10. An absolute position detection device is provided for the elevator car to obtain real-time position data S of the elevator car; S20. A vibration control module is added to the operation control system of the elevator, wherein the signal input end of the vibration control module is connected to the absolute position detection device, and the signal output end of the vibration control module outputs the elastic moment compensation value T of the wire rope to the current control module in the operation control system; the operation control system also includes a speed control module, and the signal output end of the speed control module is connected to the current control module; wherein, T = m * a(t) * r * ha / L / hk (1) In formula (1), m is the mass of the elevator car, a(t) is the instantaneous acceleration of the elevator car, r is the radius of the sheave on the main machine, ha is the torque correction coefficient, L is the distance between the elevator car and the main machine, and hk is the elastic torque compensation coefficient per unit length of the wire rope; S30. According to the elastic torque compensation value T of the steel wire rope, the PWM command output by the current control module to the host is adjusted to control the rotation speed of the host, wherein: （5） In formula (5), T0 is the control torque output by the speed control module, I m is the rated current of the motor, T m is the rated torque of the motor.

2. A method for actively suppressing elevator car vibration according to claim 1, characterized in that: The absolute position detection device is a scale detection device provided corresponding to the elevator car.

3. A method for actively suppressing elevator car vibration according to claim 1 or 2, characterized in that: After obtaining the real-time position data S of the elevator car, according to: V(t)=dS / dt(3) a(t)=dv / dt(4) The instantaneous speed of the elevator car is obtained by equation (3), and the instantaneous acceleration a(t) of the elevator car is obtained based on the obtained instantaneous speed and equation (4).

4. The method for actively suppressing elevator car vibration according to claim 1, characterized in that: The operation control system further comprises a current feedback module, a signal input end of the current feedback module is connected to a current detection device, and the current detection device is used to detect the current of the motor on the host; The signal output terminal of the current feedback module is connected to the current control module.

5. The method for actively suppressing elevator car vibration according to claim 4, characterized in that: The signal input end of the speed control module receives the rated speed instruction and the actual speed value fed back by the encoder of the host respectively.

6. A method for actively suppressing elevator car vibration according to claim 5, characterized in that: The operation control system further comprises a host speed feedback module, wherein a signal input end of the host speed feedback module is connected to an encoder of the host; The signal output end of the host speed feedback module is connected to the speed control module.

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