Emergency shutdown control system for rubber open mill

Abstract

The invention relates to the technical field of safe operation of rubber open mills, and discloses an emergency shutdown control system for a rubber open mill, comprising: a photoelectric induction module for forming an induction light curtain and collecting a reflected signal; the reflective bracelet response module is used for reflecting the wavelength light rays emitted by the photoelectric induction module; the signal processing module is used for capturing the reflected signal, analyzing the frequency spectrum of the signal and extracting the frequency corresponding to the wavelength signal; the safety logic processing module is used for presetting a specific frequency according to the wavelength frequency, only responding to wavelength signals in a preset frequency range, and triggering shutdown after response; and the emergency braking module is used for immediately braking the roller of the open mill after receiving the shutdown signal of the safety logic processing module.

Description

Technical Field

[0001] The invention relates to the technical field of safe operation of a rubber mixing mill, and in particular to an emergency shutdown control system for a rubber mixing mill. Background Art

[0002] In the rubber industry, the mixing mill is one of the core production equipment, which is used for rubber plasticizing, mixing and other process. However, when the mixing mill is in operation, especially its roller part, there is a high safety risk, especially the possibility of squeezing injury to the operator's hands. In the traditional manual operation mode, once an emergency occurs, the operator needs to immediately press the emergency stop button to stop the equipment, but due to the human reaction time and mechanical response delay, this process often cannot be completed instantly, resulting in potential serious injury accidents.

[0003] In order to solve the above problems, an emergency shutdown control system for a rubber mixing mill is proposed. Summary of the invention

[0004] The purpose of the present invention is to solve the disadvantage of the prior art that it cannot play a preventive effect when a danger occurs, and to propose an emergency shutdown control system for a rubber mixing mill.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An emergency shutdown control system for a rubber mixing mill, comprising:

[0007] Photoelectric sensing module: forms a sensing light curtain and collects reflected signals;

[0008] Reflective bracelet response module: reflects the wavelength light emitted by the photoelectric sensing module;

[0009] Signal processing module: captures the reflected signal, analyzes the signal spectrum and extracts the frequency corresponding to the wavelength signal;

[0010] Safety logic processing module: according to the wavelength frequency, preset the normal frequency, respond to the wavelength signal exceeding the preset frequency, and send a shutdown signal after responding;

[0011] Emergency brake module: After receiving the shutdown signal from the safety logic processing module, it immediately brakes the roller of the mixing mill.

[0012] The photoelectric sensing module includes a light curtain forming unit, which uses an infrared laser as a light source. The light curtain forming unit includes a transmitter and a receiver. The transmitter and the receiver are pre-installed on both sides of the mixing mill to form a light curtain. The signal processing module receives the reflected signal through the receiver.

[0013] The reflective bracelet response module includes a reflective bracelet, which reflects the wavelength light emitted from the photoelectric sensing module to the receiver through the reflective surface of the reflective bracelet, and the receiver obtains the time domain signal from the wavelength signal

[0014] The signal processing unit analyzes the wavelength light time domain signal Extract the spectrum corresponding to the wavelength It is expressed as:

[0015]

[0016] in, is the frequency, Is an imaginary unit.

[0017] The signal processing unit frequency Optimize the acquisition process and introduce adaptive filters. Different frequency components correspond to different step factors. in:

[0018]

[0019] μ base is the basic step factor, β is the influence of the control error signal on the step factor, |E(f)[n] is the The error signal E[n] at frequency Frequency domain representation of ;

[0020] Based on β, the performance index P(β) is set to reflect the step size factor Stability, for β, a range is given based on a web search Select a candidate value and derive the corresponding It is expressed as:

[0021]

[0022] in, express The error score sequence is selected as right To solve, Get the optimal β.

[0023] The safety logic processing unit obtains the frequency spectrum based on the optimal β Define the signal response range, , expressed as Using the known spectrum X(f), check the frequency range The signal strength within is expressed as:

[0024]

[0025] Δf is the frequency resolution of the spectrum, E target Indicates the maximum spectrum within the range, where Δf is proportional to the sampling time length of the signal. The signal acquisition duration is 1 second, indicating T = 1, then The spacing between frequency components will be 1 Hz.

[0026] The safety logic processing module defines the trigger threshold Compare E target and T, E target ≥T indicates that the signal within the frequency range is strong enough to respond to the emergency brake module. The surface signal is not sufficient to trigger a shutdown and the system remains operational.

[0027] The emergency brake module is in T Etarget ≥T, when the signal within the frequency range is detected to be strong enough, emergency braking is performed.

[0028] The present invention has the following beneficial effects:

[0029] 1. In the present invention, when the wristband worn by the operator enters the photoelectric ray area, the system can respond quickly and stop the equipment, greatly reducing the risk of the hand being squeezed. This response speed is much faster than the reaction time of the traditional emergency stop button, providing more immediate safety protection.

[0030] 2. In the present invention, since the braking effect of the system is activated only when the wristband is triggered and the response is rapid, it will hardly cause any interference or delay in the normal production process, which ensures production efficiency while improving workplace safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention provides a system block diagram of an emergency shutdown control system for a rubber mixing mill. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1

[0034] like Figure 1 As shown, the present invention proposes an emergency shutdown control system for a rubber mixing mill, comprising:

[0035] Photoelectric sensing module: forms a sensing light curtain and collects reflected signals;

[0036] Reflective bracelet response module: reflects the wavelength light emitted by the photoelectric sensing module;

[0037] Signal processing module: captures the reflected signal, analyzes the signal spectrum and extracts the frequency corresponding to the wavelength signal;

[0038] Safety logic processing module: according to the wavelength frequency, preset the normal frequency, respond to the wavelength signal exceeding the preset frequency, and send a shutdown signal after responding;

[0039] Emergency brake module: After receiving the shutdown signal from the safety logic processing module, it immediately brakes the roller of the mixing mill.

[0040] The photoelectric sensing module includes a light curtain forming unit, which uses an infrared laser as a light source. The light curtain forming unit includes a transmitter and a receiver. The transmitter and the receiver are pre-installed on both sides of the mixing mill to form a light curtain. The signal processing module receives the reflected signal through the receiver.

[0041] The reflective bracelet response module includes a reflective bracelet, which reflects the wavelength light emitted from the photoelectric sensing module to the receiver through the reflective surface of the reflective bracelet, and the receiver obtains the time domain signal from the wavelength signal

[0042] The signal processing unit analyzes the wavelength light time domain signal Extract the spectrum corresponding to the wavelength It is expressed as:

[0043]

[0044] in, is the frequency, Is an imaginary unit.

[0045] The signal processing unit frequency Optimize the acquisition process and introduce adaptive filters. Different frequency components correspond to different step factors. in:

[0046]

[0047] μ base is the basic step factor, β is the influence of the control error signal on the step factor, |E(f)[n] is the The error signal E[n] at frequency Frequency domain representation of ;

[0048] Based on β, the performance index P(β) is set to reflect the step size factor Stability, for β, a range is given based on a web search Select a candidate value and derive the corresponding It is expressed as:

[0049]

[0050] in, express The error score sequence is selected as right To solve, Get the optimal β.

[0051] In this embodiment, in the photoelectric sensing unit, the transmitter is composed of an infrared or laser transmitter. The light curtain area is adjusted by the activity of the customized frame to perfectly adapt to various types of open refining equipment. Generally, the interval of 2-3 cm from the intersection of the two rollers is the most suitable safety distance. This area can just cover the palm of an adult and there is also fault tolerance consideration for the inertia of equipment shutdown, and it will not cause any impact on normal production. Its task is to continuously emit a stable light beam to form a monitoring area. The reflective bracelet response module is based on a special bracelet equipped by the operator. A high-reflectivity material is embedded inside, which can effectively reflect light of a specific wavelength to ensure that the alarm can be accurately triggered even in harsh environments. The signal processing module captures the spectrum reflected by the bracelet and analyzes it to extract the corresponding frequency of the signal. The specific implementation process is as follows:

[0052] The signal processing unit analyzes and interprets the signal, converts the time domain signal into a frequency domain representation, and reveals the distribution of different frequency components in the signal. middle,

[0053] represents the signal in the time domain, X(f) is the signal in the frequency domain, and the above integral expression means multiplying the time domain signal x(t) by the complex exponential function e- j2πf , and then integrate over the entire time axis, the complex exponential function e- j2πf is a complex number of rotation, and its rotation frequency is given by This makes the original signal x(t) modulated at different frequencies, and then by calculating X(f), we can get the signal x(t) at different frequencies The amplitude and phase information under the condition is equivalent to decomposing the original signal into its constituent sinusoidal wave components. In the emergency shutdown control system, the signal processing unit can identify the specific frequency components of the bracelet reflection signal, thereby preliminarily distinguishing it from background noise or other interference sources. In the application of the system, when the photoelectric module receives the signal reflected by the bracelet, the signal contains the reflection information of light of a specific wavelength, corresponding to a certain frequency component. Through the above operation, the photoelectric signal in the time domain is converted into the frequency domain, so that the characteristic frequency of the bracelet reflection signal can be highlighted, the noise and interference of other frequencies can be filtered out, and only the specific frequency range of the bracelet reflection signal is allowed to pass;

[0054] On this basis, the signal processing unit frequency To optimize, the signal source is the light of a specific wavelength reflected by the bracelet, then the frequency The frequency corresponding to the wavelength is optimized. First, a frequency adaptive filter is introduced. For different frequency components, different frequency components appear corresponding to different step factors, that is, frequency Directly determines the step size factor The value of, in the frequency adaptive filter, the step factor It is also affected by the β parameter. If β is too small, the step factor will not increase significantly even in the presence of large errors, resulting in a slower convergence speed. On the contrary, if β is too large, the step factor will become very large when there is a large error, resulting in unstable or divergent calculation results of the adaptive filter. By defining the performance index P(β), it is expressed as the inverse of the final error after the algorithm converges. In this way, the higher the performance index, the better the algorithm performance. The performance index P(β) can be directly obtained by the step factor sequence Get, give a range based on network search among multiple candidate values Based on which the candidate values ​​are obtained here Select the largest right The solution is performed to obtain the best parameter value among all candidate parameters. The optimal β determines the most suitable threshold between the wristband signal and the photoelectric ray triggering shutdown, while reducing false alarms and avoiding unnecessary production interruptions. In this way, the system can more effectively protect operators from harm.

[0055] Embodiment 2

[0056] like Figure 1 As shown, based on the first embodiment, the safety logic processing unit obtains the frequency spectrum based on the optimal β Define the signal response range, , expressed as Using the known spectrum X(f), check the frequency range The signal strength within is expressed as:

[0057]

[0058] Δf is the frequency resolution of the spectrum, E target Indicates the maximum spectrum within the range, where Δf is proportional to the sampling time length of the signal. The signal acquisition duration is 1 second, indicating T = 1, then The spacing between frequency components will be 1 Hz.

[0059] The safety logic processing module defines the trigger threshold Compare E target and T, E target ≥T indicates that the signal within the frequency range is strong enough to respond to the emergency brake module. The surface signal is not sufficient to trigger a shutdown and the system remains operational.

[0060] The emergency brake module is in T Etarget ≥T, when the signal within the frequency range is detected to be strong enough, emergency braking is performed.

[0061] In this embodiment, the safety logic processes the light emitted by the receiving transmitting unit and detects that the received signal frequency exceeds E target , the signal processing module will immediately detect the change and generate an interrupt instruction. The specific implementation process is as follows:

[0062] The photoelectric detection module of the set system is monitoring the signal strength of the rubber mixing mill. It is known that the signal strength of the equipment is mainly concentrated in the range of 20Hz to 30Hz when it is operating normally. This is the main range of the equipment when it is operating normally. When the reflective bracelet worn by the operator enters the light curtain monitoring area, the system will detect changes in the signal strength in the range of 20Hz to 30Hz. When the operator approaches the equipment, the signal strength in the range will change. When it is detected that the maximum spectrum E in the set range is exceeded, the system will detect the signal strength change. target When the safety logic processing module sends an emergency stop signal, the preset frequency range is expressed as: At the same time, in order to more accurately distinguish the signal between 20Hz and 30Hz, it is necessary to ensure that Δf is small enough. When T=1, This is enough to meet our needs. The system continuously collects signals based on the reflective bracelet and light curtain and converts them into spectrum. When the signal frequency changes, it exceeds the preset threshold. This means that the position of the wristband worn by the operator has passed the light curtain, directly responding to the emergency brake module and stopping the rotation of the roller part.

[0063] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An emergency shutdown control system for a rubber mixing mill, characterized in that: include: Photoelectric sensing module: forms a sensing light curtain and collects reflected signals; Reflective bracelet response module: reflects the wavelength light emitted by the photoelectric sensing module; Signal processing module: captures the reflected signal, analyzes the signal spectrum and extracts the frequency corresponding to the wavelength signal; Safety logic processing module: according to the wavelength frequency, preset the normal frequency, respond to the wavelength signal exceeding the preset frequency, and send a shutdown signal after responding; Emergency brake module: After receiving the shutdown signal from the safety logic processing module, it immediately brakes the roller of the mixing mill.

2. An emergency shutdown control system for a rubber mixing mill according to claim 1, characterized in that: The photoelectric sensing module includes a light curtain forming unit, which uses an infrared laser as a light source. The light curtain forming unit includes a transmitter and a receiver. The transmitter and the receiver are pre-installed on both sides of the mixing mill to form a light curtain. The signal processing module receives the reflected signal through the receiver.

3. An emergency shutdown control system for a rubber mixing mill according to claim 2, characterized in that: The reflective bracelet response module includes a reflective bracelet, which reflects the wavelength light emitted from the photoelectric sensing module to the receiver through the reflective surface of the reflective bracelet, and the receiver obtains the time domain signal from the wavelength signal 4. The emergency shutdown control system for a rubber mixing mill according to claim 2, characterized in that: The signal processing unit analyzes the wavelength light time domain signal Extract the spectrum corresponding to the wavelength It is expressed as: in, is the frequency, Is an imaginary unit.

5. The emergency shutdown control system for a rubber mixing mill according to claim 4, characterized in that: The signal processing unit frequency Optimize the acquisition process and introduce adaptive filters. Different frequency components correspond to different step factors. in: μ base is the basic step factor, β is the influence of the control error signal on the step factor, |E(f)[n] is the The error signal E[n] at frequency Frequency domain representation of ; Based on β, the performance index P(β) is set to reflect the step size factor Stability, for β, a range is given based on a web search Select a candidate value and derive the corresponding It is expressed as: in, express The error score sequence is selected as right To solve, Get the optimal β.

6. The emergency shutdown control system for a rubber mixing mill according to claim 1, characterized in that: The safety logic processing unit obtains the frequency spectrum based on the optimal β Define the signal response range, expressed as Using the known spectrum X(f), check the frequency range The signal strength within is expressed as: Δf is the frequency resolution of the spectrum, E target Indicates the maximum spectrum within the range, where Δf is proportional to the sampling time length of the signal. The signal acquisition duration is 1 second, indicating T = 1, then The spacing between frequency components will be 1 Hz.

7. The emergency shutdown control system for a rubber mixing mill according to claim 1, characterized in that: The safety logic processing module defines the trigger threshold Compare E target and T, E target ≥T indicates that the signal within the frequency range is strong enough to respond to the emergency brake module. The surface signal is not sufficient to trigger a shutdown and the system remains operational.

8. The emergency shutdown control system for a rubber mixing mill according to claim 1, characterized in that: The emergency brake module is in T Etarget ≥T, when the signal within the frequency range is detected to be strong enough, emergency braking is performed.

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