Overhead Passenger Devices Automation System

The overhead passenger device automation system plays a critical role in ensuring the economic efficiency of mines. The safe and reliable operation of this system is crucial for enhancing system reliability and safety, implementing centralized monitoring, and achieving comprehensive protection and remote control. The automated and efficient operation of the overhead passenger device system requires not just an on-site control host and advanced sensors but also a supervisory upper computer capable of remotely controlling and coordinating various overhead passenger systems. This centralized control of automated control, ground dispatch remote monitoring, and video surveillance is a key direction for the development of centralized control in coal mine automation. It forms the foundation for unmanned operation in automated mining production.

High productivity, quality, safety, energy efficiency, labor reduction, reduction of on-site personnel, and ultimately cost reduction to maximize profit are essential for coal enterprises to survive and thrive in competitive markets. To develop and sustain, coal mines must pursue high productivity and efficiency and automate their operations. Through automation, they aim to reduce staffing, lower costs, and improve labor productivity. The overhead passenger automation system is a critical component of mine automation. In response, our company has independently developed an unmanned automated control system for the overhead passenger device.

Key Advantages of Implementing Overhead Passenger Automation Control:

Automated Detection and Operation: Sensors automatically detect passengers boarding and disembarking, and autonomously start and stop the carriage, enhancing operational efficiency, reducing idle power consumption, and lowering operational costs.

Reduction in Supervisory Personnel: The system allows for a significant reduction in supervisory staff, decreasing wage expenditures, fostering automation and intelligent construction, enhancing maintenance quality, reducing accidents, and shifting from reactive to proactive scheduled maintenance to improve equipment utilization.

Safety and Efficiency: The system ensures safe and efficient operation of the overhead passenger devices, preventing overspeed, rope drop, mispositioning, and other potentially dangerous incidents, thus enhancing safety and labor productivity.

1.Basic Functions of the System:

(1) The overhead passenger device system is equipped with comprehensive sensors, actuators, and controllers to meet functional requirements such as rope disengagement monitoring, automatic rope-catching in case of breakage, termination at bypass stations, and emergency stop locking.

(2) The system is capable of collecting and transmitting state signals such as operating speed, motor vibration, temperature, voltage, current, and power.

(3) The system monitors the start and stop times of the overhead passenger device, the number of passengers, operation records, and fault information. It can automatically detect load and no-load conditions, stopping automatically when unoccupied to achieve manned operation and unmanned parking.

(4) The system can issue alerts for protection actions, voltage and current over-limits, high temperature, overload, and speed anomalies, accompanied by textual and voice alerts. It records fault alarms and other operational parameters.

(5) Using configuration software, it compiles, classifies, stores, and processes data to create animated simulations of system operations; it manages real-time data, historical data, operational events, historical trend curves, histograms, and operational records.

(6) The system features flexible and diverse control modes including remote, continuous, intermittent, and maintenance modes. Both on-site and remote master computers can start and stop the equipment, offering dual local and remote control capabilities. The system automatically controls the overhead passenger device and its ancillary equipment based on device status and protection information, fulfilling unattended operation requirements.

(7) The ground control center's industrial computer runs configuration software that collects and processes data uploaded from the mine's overhead passenger device monitoring host. It enables remote operations on the system host, allowing modifications to the underground host's operating program and managing equipment start/stop actions and fault reset signals for comprehensive monitoring of the overhead passenger device operation system.

(8) Communication devices installed along the overhead passenger device enable centralized control from the ground, platform operation on site, and full-section video surveillance and voice communication along the transport route.

(9) The system has communication interface capabilities; the main host uses a German Siemens PLC and can communicate with both the touchscreen and ground master computer, facilitating data transfer, information exchange, and remote measurement, control, and adjustment functions.

(10) The system can detect personnel changes in a contactless manner. When unoccupied, it automatically reduces speed; when occupied, it starts automatically and reaches the set speed. The operation time is limited to the time set internally (based on the travel time from the head to the tail of the device, plus an additional 30 seconds before automatically reducing speed).

2. System Operating Modes

The control system has three operating modes: "Continuous", "Intermittent" and "Maintenance". By selecting the corresponding mode of operation, the selected mode of operation can be displayed on the touch screen.

(1) Continuous Mode

In "continuous" mode, selected on the touchscreen which then displays "continuous mode", the system operates 24 hours non-stop, suitable for mines with high personnel traffic. First, the "start warning" button is pressed, the safety brake motor starts simultaneously, and then the "start" button is pressed to automatically start the passenger device motor, displaying the operating status of each motor in different windows.

(2) Intermittent Mode

This energy-saving mode operates based on a preset time on the main panel (e.g., 100 seconds set in "Parameter Settings" via panel buttons). This time is set to about 50% of a complete cycle of the device operation, sufficient to transport personnel from one end to the other. In "intermittent" mode, shown on the touchscreen as "intermittent mode", the "start warning" button is pressed first, followed by the "start" button, similar to the continuous mode start (can also automatically start when passenger boarding is detected by sensors). A timer starts upon activation, and if a boarding signal is detected, the timer resets. When the remaining time reaches zero, the system will automatically stop.

(3) Maintenance Mode

In "maintenance" mode, selected on the touchscreen displaying "maintenance mode", the "start" button switches to jog start, meaning the passenger device motor starts as long as the button is pressed and stops immediately when released, while a simulated animation runs on the touchscreen showing each motor's status.

3. Display Function

The control host is equipped with a 10-inch color LCD display, capable of showing the operational status of the overhead passenger device's equipment and sensors in graphics, animations, and characters. It also displays various protection alarms and has a function for querying historical alarms.

4. System Protection Features

The overhead passenger control has multiple protection features, with corresponding actions and voice alarm notifications at the main station.

(1)Motor Fault Protection: Parameters from the mine's high voltage switch for the underground monkey car are provided by the electrical grid system. Overcurrent, leakage, and low voltage faults are monitored and controlled in real-time by the supervisory computer and PLC.

(2)Monkey Car Start Protection: When starting the monkey car, the brake is engaged first, monitoring the brake switch position signal. Once the brake is in position, the monkey car motor starts. The motor's operational feedback signal is monitored, and if there is no feedback signal 3-5 seconds after the control signal is issued, the system will stop and issue a corresponding voice alarm.

(3)Access Protection: Parameter setting requires user login to prevent unauthorized access and modifications by non-professionals.

(4)Sensor Protection: Emergency stops along the line, under-speed, over-speed, misposition, counterweight limits, passenger spacing, rope drop, motor, reducer oil temperature, etc., are all monitored. Any protection action triggers a system stop and a corresponding voice alarm.

All protection events are recorded on the ground control center supervisory computer and the local controller touchscreen's historical alarm record screen, saved for at least a year, with support for exporting to Excel or printing. Real-time alarm information is displayed in a scrolling alarm bar at the bottom of the system monitoring screen.

5. System Communication Interface

PLC System: Features RS485 communication modules and standard TCP/IP protocol Ethernet interfaces for easy connection with smart power devices or other intelligent devices on site, facilitating data read and write functions.

Communication between the PLC system and the ground supervisory computer is achieved via optical fiber.

The network utilizes open Ethernet standard technology used in industrial automation. Devices can be connected from field level to management level, supporting communication within the system and facilitating engineering and configuration within the mine, all while adhering to IT standards. This enhances the usability and maintainability of the product, using real-time Ethernet communication with data response times under 150 milliseconds.

6. Voice Intercom and Audible and Visual Alarm Functions

Voice System: The main host uses amplification telephones along the monkey car route for dialing, communication, and voice alarms, providing clear and loud audio. Monkey car inspection personnel can communicate with personnel along the line at any time, facilitating maintenance and coordination.

Ground control centers equipped with voice intercom software can conduct voice communications with the overhead passenger system.

Communication between the ground control center and the monkey car host uses Ethernet.

The system has a voice alarm feature that issues equipment start warnings ("Monkey car starting, please be cautious") and different fault alarm sounds based on fault type ("Headstock misalignment protection, headstock misalignment protection"). These alarms can be transmitted to the ground dispatch room via the network and played through speakers. The system supports ground-to-underground shouting functions, allowing communication between microphones and underground controllers.

7. Password Protection Feature

Security: Before setting parameters at the control main station, user login is required to make modifications, effectively preventing unauthorized personnel from adjusting settings.

8. Video Surveillance System

Video Monitoring: Uses video cameras to collect live image information via fiber optic communication media, uploading it directly to the ground monitoring center through the mine's ring network switch. This setup allows for convenient remote monitoring of the overhead passenger device site, enhancing system reliability and safety.

Main Functions:

(1)Information Collection: Camera captures are transmitted in real-time to display screens.

(2)Video Sub-Control Management: Monitors multiple different video signals simultaneously, enabling remote monitoring, remote access, and alarm linkage.

(3)Monitoring Function: Any video signal can be monitored on the display screens.

(4)Playback Function: Enables real-time querying and playback of images saved on the hard disk recorder.

(5)Recording Function: The hard disk recorder provides real-time and scheduled recording storage.

(6)Switching Function: Automatically cycles through pre-set images at set time intervals.

(7)Preview Function: Users can directly access IP cameras or video servers through Internet Explorer.

(8)Video File Query Function: Video files from all cameras can be searched based on time, alarm records, and other criteria.

9. Upper Computer Remote Monitoring System

The unmanned remote monitoring station for the overhead passenger device is located in the dispatch center, equipped with high-performance industrial computers, displays, supervisory software, configuration software, sound systems, gigabit switches, etc. The industrial computer runs the supervisory configuration software, displaying real-time operational parameters and status of the overhead passenger device, such as misalignment, speed, rope drop, emergency stops, motor temperature, vibration, and speed, along with fault information and video linkage. The supervisory system allows for display, storage, remote operation, and communication with underground equipment, including dialing, talking, and music playback.

Main Control Equipment

KXJ127 Mine Explosion-Proof and Intrinsically Safe Programmable Control Box: This control box is equipped with a Siemens S7-1200 series PLC, enhanced with I/O expansion modules, analog input collection modules, and standard communication processing modules. It provides comprehensive monitoring and protection for the overhead passenger device system. The control box features an embedded LCD display, which graphically and intuitively presents the operational status and protection fault information of various devices. Additionally, it supports multiple communication methods including Ethernet, RS485, and CAN bus, allowing seamless integration with other actuative components within the overhead passenger device system. Once seamlessly connected to the mine's ring network, it facilitates data uploading and computer control functions.

Associated Equipment 

(1) KTK18-D Mine Intrinsically Safe Amplification Telephone: This is a communication product specifically designed for use in underground coal mines, open-pit coal mines, and coal preparation plants. It is mainly suitable for coal mine inclines, tunnels, and other locations that are at risk of gas and coal dust explosions. The amplification telephone can perform line dialing and communication functions and can emit audible and visual alarm signals; it also receives external signals for remote audio playback.

(2) KHJ24(B) Mine Intrinsically Safe Emergency Stop Switch: Suitable for hazardous locations with explosive gas mixtures, as well as open-pit coal mines and coal preparation plants. It includes a CAN bus automatic addressing emergency stop module and is used in conjunction with a programmable control box. It serves as an emergency stop lockout for controlled devices along the line, enabling system shutdown.

(3) XB127 Mine Explosion-Proof Display: Used in underground coal mines where continuous monitoring is required. It receives 16 channels of video signals that connect with the display's internal optical receiving module, converting them into video electrical signals that enter the display's internal hard disk recorder. It synthesizes a single video image to simultaneously display 16 channels of video images on the screen. The rated working voltage is AC127V, equipped with 2 SC type interface optical terminals.

(4) KXH127 Mine Explosion-Proof and Intrinsically Safe Audible and Visual Signal Device: Suitable for use in underground coal mines at locations such as inclined rail tracks, junctions, and curves that are at risk of gas and coal dust explosions. It serves as a hoisting alarm, track switching indicator, curve warning, and signal communication to ensure safe operations.

(5) KXB127 Mine Explosion-Proof and Intrinsically Safe Audible and Visual Alarm: Primarily used in underground coal mines in areas containing explosive gases, for audible and visual alarms at transport tunnel entrances/exits or three-way junctions. During alarms, it provides voice prompts and displays scrolling text on a double-sided screen. This alarm can also serve as a voice prompt system for air doors, junctions, or passenger conveyors.

(6) ZP-12R Mine Thermoluminescent Control Sensor: This sensor features a novel structure, reliable performance, and ease of use. It is suitable for environments in mines where explosive gases (methane) and coal dust are present, such as mine transport main roads, belt conveyors, and coal storage yards. The sensor primarily consists of a probe, amplification circuit, selective frequency circuit, and output circuit. When the sensor's probe detects human body heat infrared within a 5-meter range and a 0-180 degree angle in front of it, the built-in relay closes the normally open point, transmitting a signal through the communication cable to the control main host, which then controls the start and stop of the equipment.