Control system and method for safe operation of hydraulic machine

Abstract

The invention relates to a control system and method for safe operation of a hydraulic machine. The system comprises a first visual detection device, a second visual detection device, an RFID card reading device and a control module, and the control module stores an authorized personnel information base, contains face feature data and corresponding RFID card identifiers, and is used for determining whether personnel exist in the working space of the hydraulic machine or not according to the judgment result of the first visual detection device; comparing the face images collected by the second visual detection device, and judging whether the operators are authorized personnel or not and whether the number of the operators meets a preset requirement or not; matching the RFID card identifier read by the RFID card reading device with the information base, and judging whether the RFID card identifier is consistent with the information base; when three conditions that there is no person in the working space, the operator is authorized, the number of people meets the requirement and the RFID card identifiers are matched consistently are met at the same time, a starting permission signal is output, and a starting button indicating lamp is lightened; otherwise, outputting a starting forbidding signal or giving an alarm. Safety risks caused by mistaken operation of the hydraulic machine by personnel are effectively prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic press safety, and in particular relates to a control system and method for the safe operation of a hydraulic press. Background Art

[0002] In recent years, hydraulic presses have been widely used in sheet metal forming, powder pressing, mold debugging and other industrial fields. Their working space is narrow and the slide has a large inertia. Once misoperation occurs, it is very easy to cause serious personal injuries such as pinching and sliding. In order to reduce the risk, the industry generally adopts four types of safety control measures: First, the main cylinder is equipped with a hydraulic lock, which relies on a balance valve or a cartridge valve to close the oil circuit when the machine is shut down to maintain the position of the slide; second, a mechanical safety column (also known as a safety strut) is set up, which is manually inserted during maintenance or mold change to achieve rigid support; third, a safety grating or laser scanner (commonly known as a light curtain) is arranged to cut off the control circuit when a human body enters the detection area; fourth, multi-person button interlocking requires more than two operators to press their respective start buttons at the same time before the mold can be closed.

[0003] However, the above measures all have inherent defects that make it difficult to eradicate the risk of "carelessness": the hydraulic lock is extremely sensitive to system micro-leaks and seal aging. Once pressure relief occurs, the slider may slowly sink and cause accidental pinching. The safety column needs to be manually plugged in and out, and is often omitted or misused under rhythmic production or quick mold change conditions, and cannot provide protection for the normal production process. The gratings and light curtains can only detect "intrusion events" and cannot identify the operator's normal operations such as arranging workpieces and taking samples in the mold cavity, and oil mist and reflections can easily cause shielding or false triggering. Although the multi-person button can limit the accidental start-up of a single person, it is often stuck by wooden blocks or rubber strips or pressed by other people in actual production and is manually bypassed.

[0004] Due to the combination of the above technical shortcomings and management omissions, typical accidents such as "slipping and pinching fingers" and "getting pinched while removing parts" still occur from time to time in the hydraulic press industry. According to public statistics, in the past decade, there have been many cases of serious injuries or even deaths at home and abroad due to operators illegally entering the mold area, mistakenly canceling the safety device, or ignoring the hydraulic lock pressure relief warning. These examples show that it is difficult to build a redundant and reliable protection system relying solely on traditional mechanical, hydraulic, and electronic control safety devices. There is an urgent need for a new safety control solution that can sense the position relationship between man and machine in real time, take multiple precautions against pressure loss and misoperation, and take into account production rhythm and maintenance convenience, so as to fundamentally eliminate the hidden dangers of safety injuries caused by misoperation of personnel. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a control system and method for safe operation of a hydraulic press, thereby ensuring the safety protection of operators who cross the grating or light curtain to enter the hydraulic press for operation, and effectively preventing safety risks caused by human errors.

[0006] The technical solution adopted by the present invention is: A control system for the safe operation of a hydraulic press, including

[0007] A first vision detection device, arranged above the working space of the hydraulic press, for collecting images of the working space in real time and outputting a determination result of whether a person is in / leaving;

[0008] A second vision detection device, arranged at each button operation station, for collecting the face image of the operator located at the corresponding button operation station;

[0009] An RFID card reader device, arranged at the button operation station, for reading the RFID card identification carried by the operator;

[0010] A control module, storing an authorized personnel information database containing face feature data and corresponding RFID card identifications. The control module is communicatively connected to the first vision detection device, the second vision detection device, and the RFID card reader device, and is used for:

[0011] Determining whether there is a person in the working space of the hydraulic press according to the determination result of the first vision detection device;

[0012] Comparing the face image collected by the second vision detection device to determine whether the operator is an authorized person and whether the number of operators meets the preset requirements;

[0013] Matching the RFID card identification read by the RFID card reader device with the information database to determine whether they are consistent;

[0014] When the three conditions of no person in the working space, the operator being authorized and the number of people meeting the requirements, and the RFID card identification matching are simultaneously met, an enabling signal for startup is output and the startup button indicator light is lit; otherwise, a prohibiting signal for startup is output and the indicator light remains off, or an alarm is issued.

[0015] The above technical solution proposes to use the first vision detection device, the second vision detection device, and the RFID card reader device as triple inputs, and the control module performs synchronous determination of "no person - face - RFID". Only when the three conditions are simultaneously met is an enabling signal for startup output, effectively eliminating the risk of accidental startup caused by proxy button pressing or single-person risky operation.

[0016] Preferably, the first vision detection device includes a first camera and a second camera installed at the front and rear positions above the hydraulic press slider, and the two form an overlapping monitoring area to eliminate the occlusion blind area.

[0017] Preferably, the second vision detection device includes at least one third camera installed on the left and right sides of the hydraulic press, for collecting the face image of the operator from multiple angles.

[0018] More preferably, the RFID card reader device is built-in with a timing unit, which starts timing after reading the RFID card identification; if the timing exceeds a preset threshold and the first vision detection device still recognizes that the operator is located in the operation space, the control module outputs a timeout alarm signal.

[0019] More preferably, the RFID card is fixedly arranged in the chest area of the operator's reflective vest; when the RFID card reader device fails to read the authorized RFID card identification within a preset scanning period, the control module locks the hydraulic press and records an event log.

[0020] In the above technical solution, the RFID card is fixedly sewn on the chest of the reflective vest, which not only ensures that the operator carries the identity identification at all times, but also can use the vision system to assist in detecting the highly visible color of the vest, further reducing the hidden danger of personnel not wearing personal protective equipment.

[0021] More preferably, it further includes a hydraulic state monitoring unit, which is arranged on the main cylinder oil circuit of the hydraulic press and includes at least a pair of redundant pressure sensors; when the pressure sensor detects that the oil circuit pressure is lower than a preset pressure relief threshold, the control module immediately outputs an emergency stop signal to drive the hydraulic brake valve to close and lock the slider position.

[0022] More preferably, the two pressure sensors of the hydraulic state monitoring unit are respectively connected to independent input channels of the control module, and the control module cross-checks the two pressure data. If the difference between the two exceeds the set tolerance range, it is determined that the sensor fails and a fault shutdown signal is output.

[0023] More preferably, the control module includes an event recording and remote communication sub-module, which is used to store the personnel identity verification result, hydraulic state, start / stop instruction and abnormal alarm in the form of a time stamp, and upload them to the upper computer or cloud server in real time through the industrial Ethernet or 5G network for safety audit and maintenance tracking.

[0024] More preferably, the first vision detection device is configured with a depth camera function and executes a pose recognition algorithm based on a convolutional neural network in the control module; when it detects that the operator is in at least a preset dangerous pose including bending down and leaning forward and is still in the operation space, the control module outputs a start prohibition signal and triggers an audible and visual alarm.

[0025] A control method using the control system for the safe operation of a hydraulic press includes the following steps:

[0026] Step S1: The first vision detection device continuously collects images of the hydraulic press operation space in real time, and performs a determination of whether a person is in / leaving in the control module to obtain a determination result of "no one in the operation space" or "someone in the operation space";

[0027] Step S2: The second vision detection device collects the face images of the operators at each button operation station and extracts the face feature vectors.

[0028] Step S3: The RFID card reader device reads the RFID card identification of the operator.

[0029] Step S4: The control module accesses the authorized personnel information database, compares the face feature vectors obtained in Step S2 with the authorized face features stored in the database to confirm whether the identity and number of the operators meet the preset requirements; meanwhile, matches the RFID card identification read in Step S3 with the corresponding identification in the database.

[0030] Step S5: The control module respectively receives the determination result of the operation space in Step S1, the face comparison result in Step S4, and the RFID card identification matching result; if and only if:

[0031] a) There is no one in the operation space;

[0032] b) The operator's identity is authorized and the number of operators meets the preset requirements;

[0033] c) The RFID card identification is consistent with the authorized information;

[0034] When all three conditions are satisfied simultaneously, go to Step S6; otherwise, go to Step S7.

[0035] Step S6: The control module outputs a start permission signal, synchronously lights up the start button indicator light, and allows the hydraulic press control circuit to close to drive the slider to move.

[0036] Step S7: The control module outputs a start prohibition signal, keeps the indicator light off, and triggers an audible and visual or network alarm.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] The present invention integrates five major functions, namely personnel detection in the working space, two-factor identity verification (face + RFID), real-time monitoring of hydraulic pressure loss, AI pose recognition, and event traceability, into the same control system to construct a hierarchical safety architecture of hardware-software-human factor collaboration. The hydraulic press is only allowed to start when the three conditions of "no one in the working space, the authorized number of people in place, and the RFID card identification matching" are simultaneously met. During operation, the depth vision algorithm is used to continuously monitor dangerous poses, and the double-redundancy pressure sensors are used to instantaneously handle pressure loss and sliding. Once a person enters by mistake, pressure loss occurs, or a sensor fails, the system will automatically stop tightly and give an alarm. At the same time, all start-stop and abnormal events are uploaded to the cloud in real time to achieve compliant and auditable digital safety management. Compared with the traditional single protection solutions that rely on light curtains, hydraulic locks, or two-hand buttons, the present invention significantly reduces the probability of personal injury caused by accidental start-up, accidental entry, or pressure relief without increasing the production cycle, reduces the operation risk of the hydraulic press, and greatly improves the equipment safety integrity level and maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of the hydraulic press of the present invention;

[0040] Figure 2 is a side view of the hydraulic press of the present invention;

[0041] Figure 3 is a top view of the hydraulic press of the present invention;

[0042] Figure 4 is a schematic structural diagram of the button operation station of the present invention;

[0043] Figure 5 is a schematic diagram of the position of the RFID card reader device of the present invention;

[0044] In the figure, 1 - hydraulic press, 2 - first camera, 3 - second camera, 4 - third camera, 5 - first button operation station, 6 - second button operation station, 7 - third button operation station, 8 - fourth button operation station, 9 - RFID card reader device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings. It should be noted here that the description of these embodiments is for helping to understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] As Figures 1-5 shown, the present invention provides a control system for the safe operation of a hydraulic press, including

[0047] The first vision detection device is set above the working space of the hydraulic press 1 and is used to collect images of the working space in real time and output the determination result of whether a person is in / leaving the area;

[0048] The second vision detection device is set at each button operation station and is used to collect the face images of the operators located at the corresponding button operation stations;

[0049] The RFID card reading device 9 is set at the button operation stations (the first button operation station 5 to the fourth button operation station 8 in this embodiment) and is used to read the RFID card identification carried by the operator;

[0050] The control module stores an authorized personnel information database, which contains face feature data and corresponding RFID card identifications. The control module is communicatively connected to the first vision detection device, the second vision detection device, and the RFID card reading device, and is used for:

[0051] Determine whether there are personnel in the working space of the hydraulic press according to the determination result of the first vision detection device;

[0052] Compare the face images collected by the second vision detection device to determine whether the operator is an authorized person and whether the number of operators meets the preset requirements;

[0053] Match the RFID card identification read by the RFID card reading device with the information database to determine whether they are consistent;

[0054] When the three conditions of no person in the working space, the operator being authorized and the number of people meeting the requirements, and the RFID card identification matching are simultaneously met, output a start permission signal and light up the start button indicator; otherwise, output a start prohibition signal and keep the indicator off, or issue an alarm.

[0055] In the above solution, the first vision detection device includes a first camera 2 and a second camera 3 installed at the front and rear positions above the slider of the hydraulic press 1, and the two form an overlapping monitoring area to eliminate the occlusion blind area.

[0056] In the above solution, the second vision detection device includes at least one third camera 4 installed on the left and right sides of the hydraulic press 1 and is used to collect the face images of the operators from multiple angles.

[0057] The RFID card reading device 9 is built-in with a timing unit, which starts timing after reading the RFID card identification; if the timing exceeds the preset threshold and the first vision detection device still recognizes that the operator is in the working space, the control module outputs an overtime alarm signal.

[0058] The RFID card is fixedly set in the chest area of the operator's reflective vest; when the RFID card reading device does not read the authorized RFID card identification within the preset scanning period, the control module locks the hydraulic press and records the event log.

[0059] It also includes a hydraulic state monitoring unit, which is arranged on the oil path of the main cylinder of the hydraulic press and includes at least a pair of redundant pressure sensors; when the pressure sensor detects that the oil path pressure is lower than the preset pressure relief threshold, the control module immediately outputs an emergency stop signal to drive the hydraulic brake valve to close and lock the position of the slider.

[0060] The two pressure sensors of the hydraulic state monitoring unit are respectively connected to the independent input channels of the control module. The control module performs cross-check on the two-way pressure data. If the difference between the two exceeds the set tolerance range, it is determined that the sensor is faulty and a fault shutdown signal is output.

[0061] The control module includes an event recording and remote communication sub-module, which is used to store the personnel authentication result, hydraulic state, start / stop instruction and abnormal alarm in the form of time stamps, and upload them to the upper computer or cloud server in real time through the industrial Ethernet or 5G network for safety audit and maintenance tracking.

[0062] The first vision detection device is configured with a depth camera function and executes a pose recognition algorithm based on a convolutional neural network in the control module; when it detects that the operator is in at least a preset dangerous pose including bending down and reaching forward and is still within the working space, the control module outputs a start prohibition signal and triggers an audible and visual alarm.

[0063] The present invention also provides a control method using the control system for the safe operation of the hydraulic press, including the following steps:

[0064] Step S1: The first vision detection device collects the image of the working space of the hydraulic press in real time, and performs a determination of whether there is someone in the working space in the control module to obtain a determination result of "no one in the working space" or "someone in the working space";

[0065] Step S2: The second vision detection device collects the face image of the operator at each button operation station and extracts the face feature vector;

[0066] Step S3: The RFID card reading device reads the RFID card identification carried by the operator;

[0067] Step S4: The control module accesses the authorized personnel information database, compares the face feature vector obtained in step S2 with the authorized face features stored in the database to confirm whether the identity and number of the operator meet the preset requirements; at the same time, matches the RFID card identification read in step S3 with the corresponding identification in the database;

[0068] Step S5: The control module respectively receives the working space determination result of step S1, the face comparison result of step S4 and the RFID card identification matching result; when and only when:

[0069] a) The working space is unoccupied;

[0070] b) The operator's identity is authorized and the number of operators meets the preset requirements;

[0071] c) The RFID card identification is consistent with the authorized information;

[0072] When all three conditions are met, proceed to step S6; otherwise, proceed to step S7;

[0073] Step S6: The control module outputs a start permission signal, synchronously lights up the start button indicator, and allows the hydraulic press control circuit to close to drive the slider to move;

[0074] Step S7: The control module outputs a start prohibition signal, keeps the indicator off, and triggers an audible and visual or network alarm.

[0075] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall be covered by the protection scope of the present invention. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. A control system for the safe operation of a hydraulic press, characterized in that: including A first vision detection device, which is arranged above the working space of the hydraulic press and is used to collect images of the working space in real time and output the determination result of whether a person is in / leaving; A second vision detection device, which is arranged at each button operation station and is used to collect the face images of the operator located at the corresponding button operation station; An RFID card reading device, which is arranged at the button operation station and is used to read the RFID card identification carried by the operator; A control module, which stores an authorized personnel information database containing face feature data and corresponding RFID card identifications. The control module is communicatively connected to the first vision detection device, the second vision detection device and the RFID card reading device, and is used for: Determining whether there is a person in the working space of the hydraulic press according to the determination result of the first vision detection device; Comparing the face images collected by the second vision detection device to determine whether the operator is an authorized person and whether the number of operators meets the preset requirements; Matching the RFID card identification read by the RFID card reading device with the information database to determine whether they are consistent; When the three conditions of no person in the working space, the operator being authorized and the number of people meeting the requirements, and the RFID card identification matching are met simultaneously, output a start permission signal and light up the start button indicator; otherwise, output a start prohibition signal and keep the indicator off, or issue an alarm.

2. The control system for safe operation of a hydraulic press according to claim 1, characterized in that: The first vision detection device includes a first camera and a second camera installed at the front and rear positions above the hydraulic press slider, and the two form an overlapping monitoring area to eliminate the occlusion blind area.

3. A control system for the safe operation of a hydraulic press according to claim 1, characterized in that: The second vision detection device includes at least one third camera installed on the left and right sides of the hydraulic press, which is used to collect the face images of the operator from multiple angles.

4. A control system for safe operation of a hydraulic press according to claim 1, characterized in that: The RFID card reading device is built-in with a timing unit, which starts timing after reading the RFID card identification; if the timing exceeds the preset threshold and the first vision detection device still recognizes that the operator is in the working space, the control module outputs a timeout alarm signal.

5. The control system for safe operation of a hydraulic press according to claim 1 or 4, characterized in that: The RFID card is fixedly arranged in the chest area of the operator's reflective vest; when the RFID card reading device does not read the authorized RFID card identification within the preset scanning period, the control module locks the hydraulic press and records the event log.

6. The control system for safe operation of a hydraulic press according to claim 1, wherein: It also includes a hydraulic state monitoring unit, which is arranged on the main cylinder oil circuit of the hydraulic press and includes at least a pair of redundant pressure sensors; when the pressure sensor detects that the oil circuit pressure is lower than the preset pressure relief threshold, the control module immediately outputs an emergency stop signal to drive the hydraulic brake valve to close and lock the slider position.

7. A control system for safe operation of a hydraulic press according to claim 6, characterized in that: The two pressure sensors of the hydraulic state monitoring unit are respectively connected to the independent input channels of the control module, and the control module cross-checks the two-way pressure data. If the difference between the two exceeds the set tolerance range, it is determined that the sensor is faulty and a fault shutdown signal is output.

8. A control system for safe operation of a hydraulic press according to claim 1, characterized in that: The control module includes an event recording and remote communication sub-module, which is used to store the personnel identity verification results, hydraulic states, start / stop instructions and abnormal alarms in the form of time stamps, and upload them to the upper computer or cloud server in real time through the industrial Ethernet or 5G network for security auditing and maintenance tracking.

9. A control system for safe operation of a hydraulic press according to claim 1, characterized in that: The first visual detection device is configured with a depth camera function and executes a pose recognition algorithm based on a convolutional neural network in the control module; when it detects that the operator is in at least a preset dangerous pose including bending down and leaning forward and is still within the operation space, the control module outputs a start prohibition signal and triggers an audible and visual alarm.

10. A control method using the control system for safe operation of a hydraulic press according to any one of claims 1-9, characterized in that, It includes the following steps: Step S1: The first visual detection device collects the hydraulic press operation space image in real time and performs a determination of whether a person is in / leaving the operation space in the control module to obtain a determination result of "no person in the operation space" or "person in the operation space". Step S2: The second visual detection device collects the face images of the operator at each button operation station and extracts the face feature vectors. Step S3: The RFID card reader device reads the RFID card identification of the operator. Step S4: The control module accesses the authorized personnel information database, compares the face feature vectors obtained in Step S2 with the authorized face features stored in the database to confirm whether the identity and number of the operator meet the preset requirements; at the same time, matches the RFID card identification read in Step S3 with the corresponding identification in the database. Step S5: The control module respectively receives the operation space determination result of Step S1, the face comparison result of Step S4, and the RFID card identification matching result; if and only if: a) There is no person in the operation space; b) The operator's identity is authorized and the number of operators meets the preset requirements; c) The RFID card identification is consistent with the authorized information; When all three conditions are met simultaneously, go to Step S6, otherwise go to Step S7; Step S6: The control module outputs a start permission signal, synchronously lights up the start button indicator light, and allows the hydraulic press control circuit to close to drive the slider to move. Step S7: The control module outputs a start prohibition signal, keeps the indicator light off, and triggers an audible and visual or network alarm.

Images