WO2023272573A1

WO2023272573A1 - Contracting-brake failure protection method and apparatus

Info

Publication number: WO2023272573A1
Application number: PCT/CN2021/103477
Authority: WO
Inventors: 许晋宁; 陈恩普; 张志�; 张东花
Original assignee: 深圳市英威腾电气股份有限公司
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-01-05
Also published as: CN117440923A

Abstract

Disclosed in the present invention are a contracting-brake failure protection method and apparatus. The method comprises: when a contracting brake is in a failure state, enabling an open-loop zero servo control mode; in the open-loop zero servo control mode, determining an electric motor starting frequency which matches the current falling speed of a lifting load; controlling an electric motor to start at the electric motor starting frequency, and thus applying an upward pulling force to the lifting load by means of the electric motor, so as to control the lifting load to start to descend at the falling speed; and once the electric motor is started, adjusting the operation frequency of the electric motor from the electric motor starting frequency to a preset lowering frequency, so as to control the lifting load to descend to the ground at a smaller speed corresponding to the lowering frequency. By means of the present invention, there is no need for the action of an anti-falling device, and when a contracting brake fails, an open-loop zero servo control mode can be enabled, such that a lifting load safely descends to the ground when a mechanical shock suffered by a lifting mechanism is effectively reduced and the braking comfort is improved, thereby improving the working safety of the lifting mechanism.

Description

A brake failure protection method and device

technical field

The invention relates to the field of control technology, in particular to a method and device for protecting a brake failure.

Background technique

Construction hoists can be mechanical equipment used to lift people and goods in places such as construction sites and high-rise buildings. With the improvement of industrial automation control technology, the control technology of construction elevators is also continuously improved.

At present, the prior art can use the fall arrester to ensure the safety of the construction hoist. Specifically, when the construction elevator is running to the target floor, the closing command can be output to the holding brake. Tighten the cage so that the cage can hang stably in the air; if the brake brake cannot hold the cage tightly due to damage to the brake or insufficient brake torque, it will cause the cage to fall, and the fall arrester will start Action, forcibly lock the gears to prevent the cage from continuing to fall.

However, when the holding brake fails, the prior art cannot effectively protect the construction hoist.

Contents of the invention

In view of the above problems, the present invention provides a brake failure protection method and device that overcomes the above problems or at least partially solves the above problems. The technical solution is as follows:

A brake failure protection method, comprising:

When the holding brake is in a failure state, start an open-loop zero-servo control mode;

In the open-loop zero-servo control mode: determine the motor starting frequency that matches the current falling speed of the lifting load; control the motor to start at the starting frequency of the motor, so as to apply a upward pulling force to control the lifting load to descend from the falling speed; when the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to the preset The lowering frequency is set to control the lifting load to descend to the ground at the target speed corresponding to the lowering frequency.

Optionally, when the holding brake is in a failure state, the open-loop zero-servo control mode is started, including:

When the holding brake is in an invalid state and the falling speed of the lifting load is lower than a preset speed threshold, the open-loop zero-servo control mode is started;

The method also includes:

When the holding brake is in a failure state and the falling speed of the lifting load is not less than the speed threshold, the anti-fall device is activated to brake the lifting load.

Optionally, controlling the motor to start at the starting frequency of the motor, so as to control the lifting load to descend from the falling speed by applying an upward pulling force to the lifting load through the motor, include:

Controlling the motor to start under the preset input current and the starting frequency of the motor, so that when the torque output capability of the motor is improved, the motor applies an upward pulling force to the lifting load to control the The lifting load begins to descend from the falling speed.

Optionally, before starting the open-loop zero-servo control mode when the holding brake is in a failure state, the method further includes:

After sending the closing signal to the brake, continuously monitor the pulse count value sent by the encoder for measuring the number of rotations of the gear;

When the change value of the pulse count value is greater than the preset first pulse count change threshold value, it is determined that the brake is in a failure state, and the change value of the pulse count value is the difference between the currently monitored pulse count value and the initial value, The initial value is the pulse count value detected for the first time after the closing signal is sent to the brake.

Optionally, after the open-loop zero-servo control mode is started, the method further includes:

During the first preset time length, continuously monitor the pulse count value sent by the encoder, and when the change value of the pulse count value within the second preset time length is less than the second preset pulse count change threshold, determine the encoding If the device malfunctions, it is determined that the holding brake is actually in a non-failure state;

Exit the open-loop zero-servo control mode when it is determined that the holding brake is actually in a non-failure state.

A brake failure protection device, comprising: a first starting unit, a first determination unit, a control unit and an adjustment unit, wherein:

The first starting unit is configured to execute: when the holding brake is in a failure state, start an open-loop zero-servo control mode;

The first determination unit is configured to perform: in the open-loop zero-servo control mode, determine the starting frequency of the motor that matches the current falling speed of the lifting load;

The control unit is configured to: control the motor to start at the motor starting frequency, so that the motor can apply an upward pulling force to the lifting load to control the lifting load from the falling speed begin to descend;

The adjusting unit is configured to perform: after the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to a preset lowering frequency, so as to control the lifting The load descends to the ground at the target speed corresponding to the lowering frequency.

Optionally, the first startup unit is configured to execute:

The device also includes: a second startup unit; the second startup unit is configured to execute:

Optionally, the control unit is configured to:

Optionally, the device further includes: a first monitoring unit and a second determining unit, wherein:

The first monitoring unit is configured to perform: before starting the open-loop zero-servo control mode when the holding brake is in a failure state, after sending a closing signal to the holding brake, continuously monitor The pulse count value sent by the encoder to measure the number of revolutions of the gear;

The second determination unit is configured to perform: when the change value of the pulse count value is greater than the preset first pulse count change threshold, determine that the brake is in a failure state, and the change value of the pulse count value is currently monitored The difference between the detected pulse count value and the initial value, the initial value is the pulse count value detected for the first time after the closing signal is sent to the brake.

Optionally, the device further includes: a second monitoring unit, a third determining unit, and an exit unit, wherein:

The second monitoring unit is configured to perform: after the start of the open-loop zero-servo control mode, continuously monitor the pulse count value sent by the encoder within a first preset duration;

The third determining unit is configured to execute: when the change value of the pulse count value within the second preset time length is less than a preset second pulse count change threshold, determine that the encoder has a malfunction, and determine that the The holding brake is actually in a non-failure state;

The exit unit is configured to perform: exiting the open-loop zero-servo control mode when it is determined that the holding brake is actually in a non-failure state.

The brake failure protection method and device proposed by the present invention can start the open-loop zero-servo control mode when the brake brake is in the failure state, and in the open-loop zero-servo control mode, it is determined to match the current falling speed of the lifting load The starting frequency of the motor is controlled to start the motor at the starting frequency of the motor, so that the upward pulling force is applied to the lifting load by the motor to control the lifting load to descend from the falling speed. When the motor starts at the starting frequency of the motor, the motor's The operating frequency is adjusted from the starting frequency of the motor to the preset lowering frequency to control the lifting load to descend to the ground at the target speed corresponding to the lowering frequency. The invention can start the open-loop zero-servo control mode when the brake fails without adding any external detection equipment and controllers, effectively reducing the mechanical impact on the lifting mechanism and improving braking comfort , to safely control the lifting load to the ground, effectively improving the reliability and safety of the brake failure protection, without the need to operate the fall arrester, reducing the damage probability of the fall arrester, and improving the reliability of the fall arrester.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the specific embodiments of the present invention are enumerated below.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present application, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

FIG. 1 shows a flow chart of a first brake failure protection method provided by an embodiment of the present invention;

Fig. 2 shows a flow chart of a second brake failure protection method provided by an embodiment of the present invention;

FIG. 3 shows a flowchart of a fourth brake failure protection method provided by an embodiment of the present invention;

Fig. 4 shows a flowchart of a sixth brake failure protection method provided by an embodiment of the present invention;

Fig. 5 shows a schematic structural view of the first brake failure protection device provided by the embodiment of the present invention;

Fig. 6 shows a schematic structural diagram of a second brake failure protection device provided by an embodiment of the present invention;

Fig. 7 shows a schematic structural diagram of a fourth brake failure protection device provided by an embodiment of the present invention.

detailed description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

As shown in FIG. 1 , the present embodiment proposes a first brake failure protection method, which may include the following steps:

S101. When the holding brake is in an invalid state, start the open-loop zero-servo control mode;

Wherein, the holding brake may be a holding brake in the lifting mechanism. The lifting mechanism can be mechanical equipment used to lift people and goods in places such as construction sites and high-rise buildings, such as construction hoists, cranes and cranes.

It can be understood that the load of the lifting mechanism, that is, the lifting load, may include the cage, people and goods in the cage, and the like.

Specifically, the present invention can be applied to a frequency converter or a frequency conversion integrated machine system of a lifting mechanism. For example, when the lifting mechanism is a crane, the present invention can be applied to the frequency converter of the crane; as another example, when the lifting mechanism is a construction elevator, the present invention can be applied to the frequency conversion integrated machine system of the construction elevator.

It should be noted that the zero-servo in the prior art can be a closed-loop zero-servo, which means that when the operating command of the frequency converter or the integrated frequency conversion machine system is valid, if an instruction of zero operating frequency is given to the motor, it can be used The motor has a large enough zero-speed torque, and can always maintain the zero-speed state.

Among them, the closed-loop zero servo can be used in the closed-loop control mode. The present invention can design an open-loop zero-servo control mode, and can use the open-loop zero-servo control mode to be used in the open-loop control mode Zero servo, in the case of effectively reducing the mechanical impact force generated by the sudden drop of the lifting load, the lifting load is braked, and the lifting load is controlled to drop to the ground at a certain speed, and it is braked and supported by the base spring set on the ground Lifting loads to ensure the safety of lifting loads.

S102. In the open-loop zero-servo control mode: determine the starting frequency of the motor that matches the current falling speed of the lifting load;

Specifically, after the present invention enters the open-loop zero-servo control mode, a series of control processes can be executed correspondingly until the lifting load is controlled to the ground.

Wherein, the falling speed may be the speed of the lifting load during the falling process. It can be understood that if the gear friction force and wind resistance and other resistances are ignored when the brake brake fails, it can be considered that the lifting load will fall in a free fall motion. At this time, the present invention can use the free fall speed calculation formula to estimate its fall speed.

Specifically, the present invention can estimate the falling speed of the lifting load by obtaining the pulse count value sent by the encoder installed at the gear position for measuring the number of rotations of the gear. It is also possible to newly set the measurement accuracy in the lifting mechanism. A high speed sensor is used to determine the falling speed of the lifting load.

Wherein, the starting frequency of the motor may be the running frequency of the motor during the starting process.

It should be noted that the lifting load can drag the motor to rotate during the falling process, during which the falling speed of the lifting load corresponds to the rotation speed at which the motor is driven. However, the present invention can determine the current dragged speed of the motor when it is determined that the brake brake fails and enters the open-loop zero-servo control mode, and can control the motor to start at the motor starting frequency corresponding to the dragged speed, so that the motor can During the process, it can directly reach the dragged speed, effectively reduce the mechanical impact of the lifting mechanism due to braking the lifting load, reduce the loss of the lifting mechanism, protect the safety of people or goods in the lifting load, and improve the comfort during the braking process sex.

Specifically, the present invention can first calculate the current falling speed of the lifting load when entering the lifting open-loop control mode, then calculate the current driven speed of the motor according to the falling speed, and then calculate the current speed of the motor according to the current driven speed of the motor. The corresponding running frequency is the starting frequency of the motor.

S103. Control the motor to start at the motor starting frequency, so as to apply an upward pulling force to the lifting load through the motor to control the lifting load to start falling from the falling speed;

Wherein, step S103 may be an execution step in the open-loop zero-servo control mode of the present invention.

Wherein, the present invention can control the motor to start at the starting frequency of the motor after calculating the starting frequency of the motor, so that the lifting load can be controlled to drop from the falling speed when entering the open-loop zero-servo control mode.

Specifically, in the process of controlling the motor to start at the motor starting frequency according to the present invention, the corresponding motor input current can be calculated and input into the motor according to data such as the weight, speed and falling acceleration of the lifting load, and the rotation of the motor is controlled to move toward the lifting speed. The load exerts an upward pulling force, outputs a sufficient torque to the lifting load, effectively brakes the lifting load in the accelerated falling state, controls the lifting load to leave the acceleration state, and enables the lifting load to start in the open-loop zero-servo control mode The falling speed starts to drop at a constant speed, so as to prevent the lifting load from entering the state of losing control and accelerating the fall.

S104. After the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to a preset lowering frequency, so as to control the lifting load to drop to the ground at a target speed corresponding to the lowering frequency.

It should be noted that step S104 may be an execution step in the open-loop zero-servo control mode of the present invention.

Wherein, the lowering frequency can be the running frequency lower than the starting frequency of the motor, or it can be the running frequency not lower than the starting frequency of the motor.

Wherein, the lowering frequency can be set by technicians according to the actual working conditions of the lifting mechanism, which is not limited in the present invention.

Wherein, the target speed may be the falling speed corresponding to the lifting load when the operating frequency of the motor is stable at the lowering frequency. It can be understood that the target speed may be lower than the falling speed corresponding to the starting frequency of the motor, or the target speed may not be lower than the falling speed corresponding to the starting frequency of the motor.

Optionally, when setting the target speed in the present invention, it is prohibited to set the target speed too small to avoid insufficient output torque of the motor, and at the same time it is prohibited to set the target speed to be too large to avoid excessive damage when the lifting load reaches the ground. mechanical shock.

It should be noted that the present invention can utilize the displacement sensor originally provided in the lifting mechanism to determine the height of the lifting load during the falling process, or a new displacement sensor with more accurate measurement accuracy can be installed in the lifting mechanism to determine the height of the lifting load during the falling process. The height at which it is during the process to determine whether the lifting load reaches the ground.

Specifically, the present invention can directly exit the open-loop zero-servo control mode after the lifting load is controlled to reach the ground, and the lifting load is supported and braked by the base spring set on the ground, reducing the load while ensuring the safety of the lifting load. Consumption of control resources.

It can be understood that after the motor is started, the present invention can control the rotation speed of the motor by adjusting the operating frequency of the motor, and then control the falling speed of the lifting load. Wherein, when the operating frequency of the motor is higher, the rotational speed of the motor is greater, and the falling speed of the lifting load is greater; when the operating frequency of the motor is lower, the rotating speed of the motor is smaller, and the falling speed of the lifting load is smaller.

Specifically, the present invention can adjust the operating frequency of the motor from the starting frequency of the motor to the preset lowering frequency after the motor is started. When the motor can output a large enough torque, the whereabouts of the lifting load can be adjusted by adjusting the motor speed. Adjust the speed to the target speed until the lifting load is controlled to drop to the ground, reducing the braking impact of the lifting load when it reaches the ground, and improving the safety of the lifting load.

Optionally, in the present invention, a technician may first determine the target speed, and then determine the corresponding lowering frequency according to the target speed.

Optionally, the present invention can adjust the operating frequency of the motor by defaulting that the motor has been started after a preset period of time after the start command is sent to the motor.

Optionally, the present invention may start to monitor the operating frequency of the motor after sending the starting instruction to the motor, and when the monitored operating frequency of the motor reaches the starting frequency of the motor, it may be determined that the motor has started. At this point, step S104 may include:

When it is detected that the running frequency of the motor reaches the starting frequency of the motor, the running frequency of the motor is adjusted from the starting frequency of the motor to the lowering frequency.

Optionally, the present invention can also adjust the operating frequency of the motor multiple times in stages during the process of the lifting load falling to the ground after the motor is started, so that the falling speed of the lifting load can be increased under the condition that the motor can output sufficient torque. Multiple reductions are obtained, further improving the safety of the lifting mechanism and reducing the mechanical impact suffered by the lifting mechanism. At this time, the lowering frequency may include multiple frequency values.

Optionally, after entering the open-loop zero-servo control mode, the present invention can adjust the current lowering frequency of the motor to a smaller frequency value every time the lifting load falls for a certain period of time or height, and the motor can output enough torque In this case, gradually reduce the falling speed of the lifting load until the lifting load is lowered to the ground.

Wherein, each time the present invention reduces the operating frequency of the lifting load, it will brake the lifting load. At this time, it is necessary to ensure that the motor can output a large enough torque to hold the lifting load and prevent it from falling out of control again.

It should be noted that in the prior art, when the anti-fall device is used to brake the lifting load that falls due to the failure of the brake brake, the anti-drop device may be damaged after multiple actions, and the reliability is low. And in the prior art, the fall arrester generally only intervenes in braking when the falling speed of the lifting load is relatively high. At this time, forcible braking will generate a strong mechanical impact force, which will cause damage to the lifting load. In addition, after the fall arrester forcibly brakes the lifting load, the lifting load may always be suspended in the sky, waiting for safety personnel to handle or rescue. If there are people in the lifting load, it is easy to cause panic and there are unsafe factors.

Compared with the prior art, the present invention can set the open-loop zero-servo control mode without adding any external detection equipment and controllers, and start the open-loop zero-servo control mode when the brake fails, effectively reducing the When the lifting mechanism suffers mechanical shock and improves braking comfort, the lifting load is safely controlled to the ground, effectively improving the reliability and safety of the brake failure protection, without the need to operate the fall arrester, and reducing the damage to the fall arrester probability and improve the reliability of the fall arrester.

It should also be noted that, in the actual working process of the lifting mechanism, the present invention can use the technical solution shown in Figure 1 alone to protect the brake from failure, without using a fall arrester to protect the brake from failure, avoiding the failure of the brake. The damage problem that may be caused by multiple actions of the dropper.

Optionally, in the actual working process of the lifting mechanism, the present invention can also use the technical solution shown in Fig. 1 alone in certain periods of time to perform the brake failure protection, and in certain periods of time use the anti-drop device alone to perform the brake failure protection. Brake failure protection increases the diversity of brake failure protection methods and improves equipment utilization.

Optionally, in the present invention, the solution shown in FIG. 1 can also be used as the main solution for the failure protection of the holding brake, and the anti-fall device can be used as a backup solution for the failure protection of the holding brake. When the scheme shown in Figure 1 can be implemented normally, use the scheme shown in Figure 1 to carry out the brake failure protection. If the scheme shown in Figure 1 cannot be implemented normally due to equipment maintenance or failure, you can use the anti-fall device Perform holding brake failure protection.

The brake failure protection method proposed in this embodiment can start the open-loop zero-servo control mode when the brake brake is in the failure state, and determine the current falling speed of the lifting load in the open-loop zero-servo control mode. Motor starting frequency, control the motor starting at the starting frequency of the motor, so as to control the lifting load to descend from the falling speed, when the motor starts at the starting frequency of the motor, adjust the operating frequency of the motor from the starting frequency of the motor to the preset lowering frequency , by applying an upward pulling force to the lifting load through the motor, the lifting load is controlled to descend to the ground at a target speed corresponding to the lowering frequency. The invention can start the open-loop zero-servo control mode when the brake fails without adding any external detection equipment and controllers, effectively reducing the mechanical impact on the lifting mechanism and improving braking comfort , to safely control the lifting load to the ground, effectively improving the reliability and safety of the brake failure protection, without the need to operate the fall arrester, reducing the damage probability of the fall arrester, and improving the reliability of the fall arrester.

Based on the steps shown in FIG. 1 , as shown in FIG. 2 , this embodiment proposes a second brake failure protection method. In this method, step S101 may specifically be step S201, and the method may further include step S202, wherein:

S201. When the holding brake is in an invalid state and the falling speed of the lifting load is lower than the preset speed threshold, start the open-loop zero-servo control mode;

It should be noted that the present invention can simultaneously use the two modes of the open-loop zero-servo control mode and the anti-dropping device to perform brake failure protection. Optionally, when the brake fails, the present invention can first try to start the open-loop zero-servo control mode to protect the brake from failure. If the open-loop zero-servo control mode is abnormal and the protection cannot be effectively realized, the present invention can Then try to activate the fall arrester for brake failure protection.

Specifically, the present invention can determine whether to activate the open-loop zero-servo control mode to protect the brake from failure, or to activate the fall arrester to protect the brake from failure based on the falling speed of the lifting load.

Specifically, during the working process of the lifting mechanism, if it is detected that the holding brake fails and the falling speed of the lifting load does not reach the speed threshold, the open-loop zero-servo control mode can be activated first to perform braking protection on the lifting load.

Wherein, the speed threshold can be formulated by technicians according to the actual working conditions of the lifting mechanism, which is not limited in the present invention.

S202. When the holding brake is in an invalid state and the falling speed of the lifting load is not less than a speed threshold, activate the anti-fall device to brake the lifting load.

It can be understood that if the open-loop zero-servo control mode cannot effectively brake the lifting load, the falling speed of the lifting load will continue to increase. When the falling speed of the lifting load increases to reach or exceed the speed threshold, the present invention can determine An abnormality occurs in the open-loop zero-servo control mode, and the anti-fall device is activated to brake and protect the lifting load.

Optionally, when the falling speed of the lifting load reaches the speed threshold, the present invention can exit the open-loop zero-servo control mode, and enable the anti-fall device alone to perform brake failure protection. At this time, the consumption of control resources can be reduced. Avoid conflicts in control logic;

Optionally, when the falling speed of the lifting load reaches the speed threshold, the present invention can also start the anti-dropping device to perform the braking operation without exiting the open-loop zero-servo control mode while continuing to execute the open-loop zero-servo control mode. Failure protection, at this time, double braking can be provided for the lifting load, which improves the safety protection against the failure of the holding brake.

It should be noted that the present invention implements the failure protection of the brake brake by using the open-loop zero-servo control mode and the anti-fall device at the same time, which can realize redundant protection and further improve the reliability and reliability of the failure protection of the brake brake. safety.

The brake failure protection method proposed in this embodiment uses the open-loop zero-servo control mode and the anti-fall device to protect the brake brake failure, which can realize redundant protection and further improve the brake performance. Fail-safe reliability and security.

Based on the steps shown in FIG. 1 , this embodiment proposes a third brake failure protection method. In this method, step S102 may include:

Control the motor to start at the preset input current and motor starting frequency, so as to increase the torque output capability of the motor, and apply an upward pulling force to the lifting load through the motor to control the lifting load to start falling from the falling speed.

It can be understood that when the input current of the motor is larger, the torque output capability of the motor is stronger, and the torque that the motor can output is larger. The invention can improve the torque output capability of the motor by increasing the input current of the motor.

Wherein, the preset input current may be greater than a current value of the rated current of the motor, for example, may be 1.5 times of the rated current of the motor.

Optionally, the preset input current can be formulated by technicians according to the actual working conditions of the lifting mechanism, which is not limited in the present invention.

It should be noted that, in the open-loop zero-servo control mode of the present invention, the corresponding motor input current calculated according to data such as lifting load, speed, and falling acceleration is generally not greater than its rated current.

Specifically, the present invention can set the input current of the motor to the preset input current in the open-loop zero-servo control mode, and improve the torque output capability of the motor by increasing the input current of the motor, and control the lifting load during the process of decreasing the load. It performs effective braking to prevent the lifting load from falling out of control again, and further improves the safety and reliability of controlling the falling of the lifting load.

The brake failure protection method proposed in this embodiment can set the input current of the motor to a preset input current, increase the torque output capability of the motor by increasing the input current of the motor, and control it during the process of controlling the lifting load to drop Effective braking prevents the lifting load from falling out of control again, and further improves the safety and reliability of controlling the falling of the lifting load.

Based on the steps shown in FIG. 1 , as shown in FIG. 3 , this embodiment proposes a fourth brake failure protection method. Before step S101, the method may also include steps S301 and S302, wherein:

S301. After sending the closing signal to the brake, continuously monitor the pulse count value sent by the encoder for measuring the number of rotations of the gear;

Wherein, the encoder may be a device installed on the gear in the lifting mechanism to measure the number of rotations of the gear.

Specifically, the present invention can continuously monitor the pulse count value sent by the encoder within a preset certain period of time after sending the closing signal to the brake, and determine whether the gear is still rotating and estimate according to the change value of the pulse count value. The rotation speed and acceleration of the gear, so as to determine whether the brake brake is effective to brake the lifting load, so as to determine whether the brake brake is invalid.

S302. When the change value of the pulse count value is greater than the preset first pulse count change threshold, it is determined that the brake is in an invalid state, and the change value of the pulse count value is the difference between the currently monitored pulse count value and the initial value, The initial value is the pulse count value first detected after sending the closing signal to the holding brake.

It should be noted that, after the present invention sends a closing signal to the brake, it can continuously monitor the pulse count value sent by the encoder. Among them, the present invention can determine the pulse count value monitored for the first time during the period as the initial value of the pulse count value, and in the subsequent monitoring process, the real-time monitoring value of the pulse count value is subtracted from the initial value, and the subtracted The obtained value is determined as the change value of the pulse count value.

It can be understood that the pulse count value will not change when the brake is intact, that is, it has not failed, that is, the change value of the pulse count value is zero; when the brake brake fails, the pulse count value will change, And when the change value of the pulse count value is greater than the first pulse count change threshold value, it means that the gear is continuously rotating and the lifting load is in a falling state, and the present invention can determine that the brake is invalid.

Wherein, the first pulse count change threshold can be determined by technicians according to the actual working conditions of the lifting mechanism, which is not limited in the present invention.

Optionally, an audio player may be provided on the lifting mechanism. At this time, the fourth brake failure protection method may also include:

When it is determined that the brake brake fails, the audio player is instructed to output a brake brake failure alarm to prompt technicians to check and deal with the fault of the brake brake in time, so as to improve the efficiency of fault handling and effectively avoid the occurrence of safety accidents.

The brake failure protection method proposed in this embodiment can effectively determine whether the brake is invalid, so as to determine whether to start the open-loop zero-servo control mode, and further improve the safety and reliability of the lifting mechanism.

Based on the steps shown in FIG. 3 , this embodiment proposes a fifth brake failure protection method. After step S101, the method may further include steps S303, S304 and S305, wherein:

S303. Continuously monitor the pulse count value sent by the encoder within the first preset duration;

It should be noted that the maintenance personnel may mistakenly operate the gear with the encoder during maintenance, resulting in a change in the change value of the pulse count value. When the change value is greater than the first pulse count change threshold, the open-loop zero-servo control mode A false start will occur.

When false start occurs in the open-loop zero-servo control mode, the holding brake does not actually fail. At this time, the open-loop zero-servo control mode may not be able to impact the braking force of the opening brake for the operation control of the motor and the lifting load. The ring-zero servo control mode cannot control the lifting load to drop, and the lifting load is still in a static state. However, the holding brake will also be impacted in the open-loop zero-servo control mode, and the long-term impact may cause damage to the holding brake and reduce the reliability of the holding brake.

Specifically, the present invention can continuously monitor the change value of the pulse count value within the first preset time period after entering the open-loop zero-servo control mode, and if the change value is less than a certain value or does not change, the present invention can be determined The start of the sub-open-loop zero-servo control mode is triggered by the malfunction of the encoder, which actually does not fail.

Wherein, the first preset duration can be determined by the technician according to the actual working conditions of the lifting mechanism and maintenance, which is not limited in the present invention.

S304. When the change value of the pulse count value within the second preset time length is less than the preset second pulse count change threshold, it is determined that the encoder has malfunctioned, and it is determined that the holding brake is actually in a non-failure state;

Wherein, the second preset duration can be determined by the technician according to the actual working conditions of the lifting mechanism and maintenance, which is not limited in the present invention.

Wherein, the second pulse count change threshold can also be formulated by technicians according to the actual working conditions of the lifting mechanism and maintenance, which is not limited in the present invention.

Optionally, the second pulse count change threshold may be zero. At this time, after the present invention enters the open-loop zero-servo control mode, if the change value of the pulse count value is continuously monitored within the second preset time length and no longer changes, then the start of the open-loop zero-servo control mode can be determined. It is triggered by the malfunction of the encoder, so that it can be determined that the holding brake is not actually invalid. Of course, the second pulse count change threshold may also be non-zero.

S305. Exit the open-loop zero-servo control mode when it is determined that the holding brake is actually in a non-failure state.

Specifically, the present invention can stop executing the control command in the open-loop zero-servo control mode and exit the open-loop zero-servo control mode when it is determined that the holding brake is actually not ineffective, reducing the consumption of control resources.

Optionally, if within the above-mentioned first preset time length, the change value of the pulse count value within the second preset time length is not less than the second pulse count change threshold, the present invention may determine that the holding brake has actually failed, so that Continue to execute the control commands in the open-loop zero-servo control mode to control the lifting load to drop to the ground.

The brake failure protection method proposed in this embodiment can avoid the false start of the open-loop zero-servo control mode caused by the malfunction of the encoder, thereby avoiding the equipment damage caused by the false start of the open-loop zero-servo control mode and enhancing the protection against The protection of the holding brake improves the reliability of the holding brake.

Based on the steps shown in FIG. 1 , as shown in FIG. 4 , this embodiment proposes a sixth brake failure protection method. In this method, step S102 may include steps S401 and S402, wherein:

S401. Determine the motor drag speed that matches the falling speed;

Specifically, the present invention can use the relationship between the falling speed of the lifting load and the driving speed of the motor to determine the driving speed of the motor.

Optionally, step S401 may include:

Input the preset first pulse count change threshold into the speed calculation model to obtain the motor drag speed output by the speed calculation model; where the speed calculation model is:

Among them, R _l is the driving speed of the motor, k is the transmission ratio of the motor reducer, Z _p is the number of teeth of the pinion installed on the encoder, g is the acceleration of gravity, m is the modulus of the pinion, and P _f is the preset The first pulse count change threshold, P ₁ is the pulse count value for one rotation of the encoder, and Z _j is the number of teeth of the gear rack meshed.

Wherein, the first pulse count change threshold is the same value as the first pulse count change threshold in the technical solution shown in FIG. 3 .

Wherein, the first pulse count change threshold can be set by a technician according to the actual working conditions of the lifting mechanism, which is not limited in the present invention.

It should be noted that, in the open-loop zero-servo control mode, the present invention can be based on formula (1):

To calculate the drop height of the lifting load. Among them, s is the drop height. Afterwards, the present invention can utilize formula (2), and promptly initial velocity is the free-fall acceleration formula of zero:

To calculate the falling speed of the lifting load. Among them, V _t is the falling speed.

Specifically, when the present invention enters the open-loop zero-servo control mode, the rotational speed calculation model can be started, and the rotational speed calculation model can calculate and output the driving rotational speed of the motor.

S402. Calculate the starting frequency of the motor matching the driving speed of the motor.

Specifically, the present invention can calculate the starting frequency of the motor according to the relationship between the driving speed of the motor and the starting frequency of the motor.

Optionally, step S402 may include:

Input the driving speed of the motor into the frequency calculation model to obtain the motor starting frequency output by the frequency calculation model; where:

Among them, fs is the starting frequency of the motor, F is the rated frequency of the motor, R _l is the driving speed of the motor, and R is the rated speed of the motor.

Specifically, the present invention can use a frequency calculation model to calculate the starting frequency of the motor.

The brake failure protection method proposed in this embodiment can improve the calculation efficiency of determining the starting frequency of the motor, and ensure the effective implementation of the brake failure protection.

Corresponding to the method shown in FIG. 1 , as shown in FIG. 5 , this embodiment proposes a first brake failure protection device, which may include: a first starting unit 101 , a first determining unit 102 , and a control unit 103 and adjustment unit 104, wherein:

The first starting unit 101 is configured to execute: when the holding brake is in a failure state, start the open-loop zero-servo control mode;

Wherein, the holding brake may be a holding brake in the lifting mechanism. The lifting mechanism can be mechanical equipment used to lift people and goods in places such as construction sites and high-rise buildings, such as construction hoists, cranes and hoists.

Specifically, the present invention can be applied to a frequency converter or a frequency conversion integrated machine system of a lifting mechanism.

The first determination unit 102 is configured to perform: in the open-loop zero-servo control mode, determine the starting frequency of the motor matching the current falling speed of the lifting load;

The control unit 103 is configured to execute: controlling the motor to start at the motor starting frequency, so as to apply an upward pulling force to the lifting load through the motor, so as to control the lifting load to descend from the falling speed;

Wherein, the control unit 103 may be an execution unit for realizing the open-loop zero-servo control mode of the present invention.

The adjustment unit 104 is configured to execute: after the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to a preset lowering frequency, so as to control the lifting load to drop to the ground at a target speed corresponding to the lowering frequency .

Wherein, the adjustment unit 104 may be an execution unit for realizing the open-loop zero-servo control mode of the present invention.

Wherein, the lowering frequency may be an operating frequency lower than the starting frequency of the motor, or an operating frequency not lower than the starting frequency of the motor.

Optionally, the present invention may start to monitor the operating frequency of the motor after sending the starting instruction to the motor, and when the monitored operating frequency of the motor reaches the starting frequency of the motor, it may be determined that the motor has started. At this point, the adjustment unit 104 is configured to perform:

It should be noted that the first determination unit 102, the control unit 103 and the adjustment unit 104 may integrally form an open-loop zero-servo control unit. When the conditions for starting the open-loop zero-servo control mode are met, the present invention can trigger the open-loop zero-servo control unit, that is, sequentially trigger the first determination unit 102, the control unit 103 and the adjustment unit 104 to realize brake failure protection.

The brake failure protection device proposed in this embodiment can start the open-loop zero-servo control mode when the brake fails without adding any external detection equipment and controllers, and effectively reduce the mechanical damage suffered by the lifting mechanism. In the case of impact and improved braking comfort, the lifting load is safely controlled to the ground, effectively improving the reliability and safety of the brake failure protection, without the need to operate the fall arrester, reducing the damage probability of the fall arrester, and improving the fall prevention device reliability.

Based on FIG. 5 , as shown in FIG. 6 , this embodiment proposes a second brake failure protection device. In this device, the first starting unit 101 is configured to execute:

When the holding brake is in an invalid state and the falling speed of the lifting load is lower than the preset speed threshold, the open-loop zero-servo control mode is started;

At this time, the device further includes: a second startup unit 201; the second startup unit 201 is configured to execute:

When the holding brake is in an invalid state and the falling speed of the lifting load is not less than the speed threshold, the anti-fall device is activated to brake the lifting load.

The brake failure protection device proposed in this embodiment uses both the open-loop zero-servo control mode and the anti-fall device to protect the brake brake failure, which can realize redundant protection and further improve the performance of the brake brake. Fail-safe reliability and security.

Based on FIG. 5 , this embodiment proposes a third brake failure protection device. In the device, the control unit 103 is configured to perform:

The brake failure protection device proposed in this embodiment can set the input current of the motor to the preset input current, increase the torque output capability of the motor by increasing the input current of the motor, and control it during the process of controlling the lifting load to drop Effective braking prevents the lifting load from falling out of control again, and further improves the safety and reliability of controlling the falling of the lifting load.

Based on FIG. 5 , as shown in FIG. 7 , this embodiment proposes a fourth brake failure protection device. The device also includes: a first monitoring unit 301 and a second determining unit 302, wherein:

The first monitoring unit 301 is configured to execute: before starting the open-loop zero-servo control mode when the holding brake is in a failure state, after sending the closing signal to the holding brake, continuously monitor the encoder for measuring The pulse count value of the number of revolutions of the gear;

The second determining unit 302 is configured to execute: when the change value of the pulse count value is greater than the preset first pulse count change threshold, determine that the brake is in a failure state, and the change value of the pulse count value is the currently monitored pulse The difference between the count value and the initial value, the initial value is the pulse count value detected for the first time after the close signal is sent to the brake.

It can be understood that the pulse count value will not change when the brake is intact, that is, it has not failed, that is, the change value of the pulse count value is zero; when the brake brake fails, the pulse count value will change, And when the change value of the pulse count value is greater than the first pulse count change threshold, it means that the gear is continuously rotating and the lifting load is in a falling state, and the present invention can determine that the brake is invalid.

Optionally, an audio player may be provided on the lifting mechanism. At this time, the fourth brake failure protection device may further include: an alarm unit; wherein, the alarm unit is configured to execute:

The brake failure protection device proposed in this embodiment can effectively determine whether the brake is invalid, so as to determine whether to start the open-loop zero-servo control mode, and further improve the safety and reliability of the lifting mechanism.

Based on FIG. 7 , this embodiment proposes a fifth brake failure protection device. The device also includes: a second monitoring unit, a third determining unit and an exit unit, wherein:

The second monitoring unit is configured to perform: after starting the open-loop zero-servo control mode, continuously monitor the pulse count value sent by the encoder within a first preset time period;

The third determining unit is configured to execute: when the change value of the pulse count value within the second preset time length is less than the preset second pulse count change threshold, determine that the encoder has malfunctioned, and determine that the brake is actually in the non-operating position. failure state;

An exit unit configured to: exit the open-loop zero-servo control mode upon determining that the holding brake is in an actual non-failed state.

The brake failure protection device proposed in this embodiment can avoid the false start of the open-loop zero-servo control mode caused by the malfunction of the encoder, thereby avoiding the damage to the brake caused by the false start of the open-loop zero-servo control mode, and enhancing the protection against The protection of the holding brake improves the reliability of the holding brake.

Based on FIG. 5 , this embodiment proposes a sixth brake failure protection device. In this device, the first determination unit 102 may include: a fourth determination unit and a frequency calculation unit, wherein:

The fourth determination unit is configured to perform: determine the motor drag speed matching the falling speed;

Optionally, the fourth determining unit may include: a first input unit and a first obtaining unit; wherein:

The first input unit is configured to: input the preset first pulse count change threshold into the rotational speed calculation model;

The first obtaining unit is configured to execute: obtain the motor drag speed output by the speed calculation model; wherein, the speed calculation model is:

The frequency calculating unit is configured to perform: calculating the starting frequency of the motor matching the driving speed of the motor.

Optionally, the frequency calculating unit may include: a second input unit and a second obtaining unit; wherein:

The second input unit is configured to perform: input the driving speed of the motor into the frequency calculation model;

The second obtaining unit is configured to perform: obtaining the starting frequency of the motor output by the frequency calculation model; wherein:

The brake failure protection device proposed in this embodiment can improve the calculation efficiency of determining the starting frequency of the motor, and ensure the effective implementation of the brake failure protection.

It should also be noted that the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes Other elements not expressly listed, or elements inherent in the process, method, commodity, or apparatus are also included. Without further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

The above are only examples of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may occur in this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

A brake failure protection method, characterized in that, comprising:

When the holding brake is in a failure state, start an open-loop zero-servo control mode;

In the open-loop zero-servo control mode: determine the motor starting frequency that matches the current falling speed of the lifting load; control the motor to start at the starting frequency of the motor, so as to apply a upward pulling force to control the lifting load to descend from the falling speed; when the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to the preset The lowering frequency is set to control the lifting load to descend to the ground at the target speed corresponding to the lowering frequency.
The method according to claim 1, wherein when the holding brake is in a failure state, starting an open-loop zero-servo control mode includes:

When the holding brake is in an invalid state and the falling speed of the lifting load is lower than a preset speed threshold, the open-loop zero-servo control mode is started;

The method also includes:

When the holding brake is in a failure state and the falling speed of the lifting load is not less than the speed threshold, the anti-fall device is activated to brake the lifting load.
The method according to claim 1, characterized in that the motor is controlled to start at the starting frequency of the motor so as to apply an upward pulling force to the lifting load by the motor to control the lifting load Descend from the stated fall speed, including:

Controlling the motor to start under the preset input current and the starting frequency of the motor, so that when the torque output capability of the motor is improved, the motor applies an upward pulling force to the lifting load to control the The lifting load begins to descend from the falling speed.
The method according to claim 1, characterized in that, before starting the open-loop zero-servo control mode when the holding brake is in a failure state, the method further comprises:

After sending the closing signal to the brake, continuously monitor the pulse count value sent by the encoder for measuring the number of rotations of the gear;

When the change value of the pulse count value is greater than the preset first pulse count change threshold value, it is determined that the brake is in a failure state, and the change value of the pulse count value is the difference between the currently monitored pulse count value and the initial value, The initial value is the pulse count value detected for the first time after the closing signal is sent to the brake.
The method according to claim 4, characterized in that, after the open-loop zero-servo control mode is started, the method further comprises:

During the first preset time length, continuously monitor the pulse count value sent by the encoder, and when the change value of the pulse count value within the second preset time length is less than the second preset pulse count change threshold, determine the encoding If the device malfunctions, it is determined that the holding brake is actually in a non-failure state;

Exit the open-loop zero-servo control mode when it is determined that the holding brake is actually in a non-failure state.
A brake failure protection device, characterized in that it includes: a first starting unit, a first determination unit, a control unit and an adjustment unit, wherein:

The first starting unit is configured to: start an open-loop zero-servo control mode when the holding brake is in a failure state;

The first determination unit is configured to perform: in the open-loop zero-servo control mode, determine the starting frequency of the motor that matches the current falling speed of the lifting load;

The control unit is configured to execute: controlling the motor to start at the motor starting frequency, so as to apply an upward pulling force to the lifting load through the motor, so as to control the falling speed of the lifting load from the begin to descend;

The adjusting unit is configured to perform: after the motor starts at the motor starting frequency, adjust the operating frequency of the motor from the motor starting frequency to a preset lowering frequency, so as to control the lifting The load descends to the ground at the target speed corresponding to the lowering frequency.
The device according to claim 6, wherein the first starting unit is configured to execute:

When the holding brake is in an invalid state and the falling speed of the lifting load is lower than a preset speed threshold, the open-loop zero-servo control mode is started;

The device also includes: a second startup unit; the second startup unit is configured to execute:

When the holding brake is in a failure state and the falling speed of the lifting load is not less than the speed threshold, the anti-fall device is activated to brake the lifting load.
The device according to claim 6, wherein the control unit is configured to:

Controlling the motor to start under the preset input current and the starting frequency of the motor, so that when the torque output capability of the motor is improved, the motor applies an upward pulling force to the lifting load to control the The lifting load begins to descend from the falling speed.
The device according to claim 6, further comprising: a first monitoring unit and a second determining unit, wherein:

The first monitoring unit is configured to perform: before starting the open-loop zero-servo control mode when the holding brake is in a failure state, after sending a closing signal to the holding brake, continuously monitor The pulse count value sent by the encoder to measure the number of revolutions of the gear;

The second determination unit is configured to execute: when the change value of the pulse count value is greater than the preset first pulse count change threshold, determine that the brake is in a failure state, and the change value of the pulse count value is currently monitored The difference between the detected pulse count value and the initial value, the initial value is the pulse count value detected for the first time after the closing signal is sent to the brake.
The device according to claim 9, further comprising: a second monitoring unit, a third determining unit, and an exit unit, wherein:

The second monitoring unit is configured to perform: after the start of the open-loop zero-servo control mode, continuously monitor the pulse count value sent by the encoder within a first preset duration;

The third determining unit is configured to execute: when the change value of the pulse count value within the second preset time length is less than a preset second pulse count change threshold, determine that the encoder has a malfunction, and determine that the The holding brake is actually in a non-failure state;

The exit unit is configured to execute: exiting the open-loop zero-servo control mode when it is determined that the holding brake is actually in a non-failure state.